Economics & Finance

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570 domain-specific abstractions whose origin domain is Economics & Finance. They span 422 subdomains — sort by that column to group them, or click any subdomain to filter to it.

Abstraction	Subdomain	Description
Absence rate	Labor Statistics	The proportion of an employed reference population absent from usual full-time work during a specified measurement period under a declared absence definition.
Absolute Advantage	Trade Theory	A per-good comparison of output per unit input between two producers — establishing that productivity differences exist (the precondition for gains from trade) while deliberately not settling who should specialize in what.
Absolute income hypothesis	Keynesian EconomicsConsumption TheoryMacroeconomics	A Keynesian consumption hypothesis in which current real consumption rises with current real disposable income but by less than the income increase, so the marginal propensity to consume is positive and below one and average propensity tends to fall as income rises.
Abstract economy	Mathematical EconomicsGeneral Equilibrium Theory	In theoretical economics, an abstract economy (also called a generalized N-person game) is a model that generalizes both the standard model of an exchange economy in microeconomics, and the standard model of a game in game theory.
Accelerator Effect	Macroeconomics	The macroeconomic mechanism by which a change in the level of consumer demand produces a proportionally larger swing in investment, because desired capital tracks output at a fixed ratio — so it is the rate of change of demand, not the level, that drives capital ordering.
Additionality	Program Evaluation	Attribute only the outcome increment that would not have occurred without an intervention, using an explicit counterfactual baseline and adjustments for displaced, leaked, substituted, or already-planned activity.
AD–AS Model	Macroeconomics	The workhorse macroeconomic framework that plots the economy as the intersection of an aggregate-demand and an aggregate-supply schedule in price-level × output space, reading disturbances as curve shifts and diagnosing their source from a four-quadrant typology.
Agflation	Agricultural EconomicsCommodity Price Inflation	A period when food and agricultural-commodity prices rise substantially faster than the general price level, creating a sector-specific inflation gap with acute food-security and distributional consequences.
Aggregate Demand	Macroeconomics	The total planned expenditure on final goods and services at a given price level, summed as C + I + G + (X − M) and matched against aggregate supply to set short-run output and the price level.
Aggregate Supply	Macroeconomics	The total real output producers will supply at a given general price level — sloping up in the short run because wages are sticky, but vertical at potential output in the long run once the binding constraint migrates from nominal rigidity to capacity.
Alchian–Allen Effect	MicroeconomicsTrade	A common absolute per-unit charge compresses the price ratio of high- to low-grade goods and can, under specified choice conditions, shift the mix toward higher quality.
Allais Paradox	Decision Theory Under Risk	An engineered pair of lottery choices whose majority preference pattern (A over B, D over C) violates the independence axiom of expected-utility theory, isolating the certainty effect as the culprit.
Allocative efficiency	Welfare Economics	An economic state in which resources and output mix cannot be reallocated to make someone better off without making another worse off, often characterized under competitive assumptions by price equaling marginal cost.
Ambiguity Aversion	Decision Theory Under Uncertainty	The regularity that people prefer options with known probabilities over those with unknown ones even at equal expected value — a Savage-violating tilt toward the precise that the single-prior model can't represent, repaired by scoring acts against a set of priors.
Amoroso–Robinson Relation	MicroeconomicsIndustrial Organization	Relate marginal revenue to a selling price and the signed own-price elasticity of demand along a differentiable price–quantity schedule.
Anti-rival Good	Public EconomicsInformation Economics	Identify when added participation in a shared economic good increases a specified benefit available to existing users through a positive mechanism.
Applied general equilibrium	Computational EconomicsGeneral Equilibrium Models	Numerical economy-wide modeling that calibrates interdependent markets, agents, technologies and policy constraints to compute counterfactual equilibrium prices, production, income and welfare.
Arc elasticity	MicroeconomicsElasticity Measurement	A measure of one variable's proportional responsiveness to another between two observations, commonly calculated as the ratio of their midpoint percentage changes.
Arrow's Impossibility Theorem	Social Choice Theory	Prove that no ranked-preference voting rule over three or more alternatives can jointly satisfy four minimal fairness axioms — certifying the 'fair in every respect' region of design space empty and reducing the debate to which axiom to knowingly sacrifice.
Arrow–Debreu exchange market	General Equilibrium Theory	In theoretical economics, an Arrow–Debreu exchange market is a special case of the Arrow–Debreu model in which there is no production - there is only an exchange of already-existing goods.
Arrow–Debreu Model	General Equilibrium Theory	Prove that a competitive economy has a set of prices at which every market clears at once, by treating each date-and-state-indexed good as its own priced commodity and applying a fixed-point argument to joint excess demand.
Assume a Can Opener	Economic MethodologyPolicy Analysis	A critique of a proposed solution that assumes the missing capability needed to solve the original problem, then treats its conditional result as a practical answer.
Assurance Game	Game Theory and Coordination	The stag-hunt game in which each player strictly prefers to cooperate if and only if the others do, producing two self-enforcing equilibria — a payoff-dominant cooperative one and a risk-dominant defection one — so the binding constraint is mutual confidence, not incentives.
Asynchrony (game theory)	Game Theory	In game theory, asynchrony refers to a gameplay structure where interactions and decisions do not occur in uniformly timed rounds.
Atkinson index	Welfare Economics	An inequality measure equal to the proportional mean income society could forgo while retaining the same equally distributed equivalent welfare at a chosen inequality-aversion parameter.
Auction	Auction TheoryMarket Design	An auction is usually a process of buying and selling goods or services by offering them up for bids, taking bids, and then selling the item to the highest bidder or buying the item from the lowest bidder.
Austerity	Fiscal PolicyMacroeconomics	A deliberate public fiscal program intended to reduce a deficit or debt path through spending restraint, tax increases, or both, assessed against a specified policy baseline and time horizon.
Autoregressive Conditional Duration	Financial Econometrics	Model positive intervals between irregular events as a unit-mean innovation times a conditional expected duration that evolves from past durations and past conditional means.
Average variable cost	Microeconomics	Variable production cost divided by quantity of output, used in the firm's shutdown decision.
Balance of payments	International Macroeconomics	A double-entry statistical account recording a country's transactions with the rest of the world over a period across current, capital and financial accounts.
Balance-Sheet Recession	Macroeconomics	A contraction caused not by weak income but by impaired private balance sheets — after a debt-financed boom collapses, actors switch from profit maximization to paying down debt, so monetary policy goes inert and only fiscal deficits sustain demand until balance sheets heal.
Balassa-Samuelson Effect	International Economics	The mechanism by which countries with fast-growing tradable-sector productivity end up with systematically higher price levels and appreciating real exchange rates — because tradable wage gains spill through mobile labor into non-tradable prices that cross-border arbitrage cannot compete away.
Bank Run	Banking and Financial Stability	A self-reinforcing mass withdrawal or refusal to renew short-term claims on a financial institution, where a finite liquid pool rewards early exit and each withdrawal worsens later claimants' prospects, so even a solvent institution can be drained by the race.
Banzhaf power index	Cooperative Game Theory and Collective Choice	A voting-power measure based on how often a voter is critical in winning coalitions, normalized either across that voter's possible swings or across all voters' swings.
Barrier to Entry	Industrial Organization	Read market power off the durable, asymmetric cost of joining a market rather than the current count of firms — sorting each barrier into structural, strategic, or legal to select the remedy that can actually remove it.
Basis-Risk Failure	Risk Management and Derivatives	Diagnose why a hedge collapses at the worst moment: the proxy instrument, chosen for its calm-market correlation with the exposure, decouples under stress, so protection that passed every ex-ante metric evaporates exactly when it is needed.
Baumol's Cost Disease	Labor Economics and Productivity	Explain why labor-intensive sectors with little productivity growth become relatively more expensive as wages rise with productive sectors through a shared labor market while stagnant-sector output per worker does not.
Baxter's Law	Antitrust EconomicsIndustrial Organization	An economic-antitrust proposition that a regulated monopoly can leverage control of a bottleneck input or network layer to extend dominance into a potentially competitive, unregulated adjacent market.
Bayes Correlated Equilibrium	Game TheoryInformation Design	In game theory, a Bayes correlated equilibrium is a solution concept for static games of incomplete information.
Bayesian Nash Equilibrium	Game Theory	The solution concept for games of incomplete information: recast not knowing an opponent's payoffs as Nature drawing each player's private type from a common prior, then solve for a fixed point of type-conditional strategy functions where every type's action is a best response in expectation and the supporting beliefs are Bayes-consistent.
Bayesian Persuasion	Game Theory	Model how a sender who cannot lie — committed to a public, truthful signal structure faced by a Bayes-rational receiver — still shifts the receiver's action by choosing how informative the signal is, solved geometrically as the concave closure of the sender's value over posteriors.
Beauty Contest Game	Game Theory	Have players simultaneously pick a number to land closest to p times the group average, so that iterated best-response contracts the target toward zero — turning the infinite tower of 'what others expect others to expect' into a single measurable reasoning-depth scalar read off the choices.
Bertrand competition	Price Competition and Oligopoly Theory	A strategic market model in which firms choose prices while buyers select quantities at the offered prices.
Bertrand Paradox (Economics)	Industrial Organization	Compute the extreme corner of price competition — two firms selling an identical good at equal marginal cost price at marginal cost with zero profit — as a deliberately-wrong baseline whose gap to real margins becomes a five-assumption diagnostic audit.
Bertrand–Edgeworth model	Capacity Constrained Price Competition	Model homogeneous-product price competition among capacity-constrained sellers under an explicit rationing rule, so residual demand can prevent the pure marginal-cost equilibrium of unconstrained Bertrand competition.
Beta (finance)	Asset Pricing	The slope relating an asset’s returns to market returns, used as a measure of systematic covariance exposure.
Black–Scholes Model	Derivatives Pricing	Price an option without forecasting the stock by noting that a continuously rebalanced stock-and-bond portfolio can replicate its payoff exactly, so no-arbitrage forces the price to equal that replication cost — leaving volatility as the only input to estimate.
Boltzmann Fair Division	Probabilistic Allocation	A proposed probabilistic allocation model that converts contribution, need, and preference into a distribution potential and assigns resources through a Boltzmann-like probability rule.
Border's theorem	Mechanism Design	Border's theorem gives necessary and sufficient inequalities for whether interim allocation rules can be implemented by an auction.
Breusch–Godfrey test	Econometrics	A regression diagnostic testing residual serial correlation through an auxiliary regression that permits higher-order autocorrelation and lagged dependent regressors.
Breusch–Pagan test	EconometricsRegression Diagnostics	A Lagrange-multiplier regression diagnostic testing whether disturbance variance in a fitted linear model depends systematically on specified covariates rather than remaining constant.
Budget-balanced mechanism	Mechanism DesignGame Theory	In mechanism design, a branch of economics, a weakly-budget-balanced (WBB) mechanism is a mechanism in which the total payment made by the participants is at least 0.
Buffer Stock Scheme	Commodity Market PolicyPhysical Stock Price Stabilization	A commodity-price stabilization mechanism in which an authorized operator accumulates physically deliverable stock when price reaches a lower intervention trigger and releases stock when price reaches an upper trigger, using countercyclical inventory flows to resist short-run price swings within finite finance, storage, and stock constraints.
Buffered probability of exceedance	Risk Measurement	A tail-risk measure giving the probability mass of a tail whose conditional mean reaches a specified threshold, equivalently an inverse-CVaR quantity.
Buffett indicator	Financial Markets	A market-valuation ratio comparing aggregate listed-equity capitalization with a jurisdiction’s gross domestic product.
Bullwhip Effect	Supply Chain Management	Excess variability in replenishment orders relative to downstream sales or nearer-tier orders as demand information travels upstream through a supply chain.
Bundling	Industrial Organization	A seller conditions access to one good on accepting another by offering a combined package, extracting more surplus when component valuations are dispersed and negatively correlated — or leveraging market power in one good to foreclose rivals in a complementary one.
Burstable billing	Telecommunications Economics	A network-capacity charging method that bills a high percentile of sampled traffic, allowing short bursts above commitment without pricing every peak as sustained demand.
Business Cycle	Macroeconomics	Read the joint state of a whole economy off one phase label on an ordered ring — expansion, peak, contraction, trough, recovery — by tracking position relative to trend and direction of motion rather than the absolute level of activity.
Capacity utilization	Production Economics and Operations	The ratio of actual output during a period to the potential output achievable from a defined stock of productive capacity under a stated engineering or economic convention.
Capital Accumulation	Growth Theory	Track an economy's whole productive base as one state variable growing under the law of motion ΔK = I − δK, a self-feeding loop of output-saving-investment that diminishing returns brake into a steady state where thrift raises the level but not the long-run growth rate.
Capital intensity	Economics of Production	The amount of fixed or real capital used relative to labor or another production input at a process, firm, industry or economy level.
Capital Stock	Capital Theory	Treat a durable productive resource as a priced stock with four operations — investment, depreciation, accumulation, and return — plus a present-value pricing convention that renders holdings of different capital forms commensurable on one ROI ledger.
Capitalization-Weighted Index	Financial IndicesPortfolio Theory	A capitalization-weighted (or cap-weighted) index, also called a market-value-weighted index is a stock market index whose components are weighted according to the total market value of their outstanding shares.
Captive market	Industrial Organization	A market in which buyers have severely restricted practical alternatives because of monopoly, switching costs, location, compatibility, contracts, regulation, or control of access.
Carbon leakage	Climate Economics	The increase in greenhouse-gas emissions outside a regulated region caused by mitigation policy inside it, relative to the emissions reduction achieved there.
Cash Conversion Cycle	Working CapitalFinancial Analysis	A working-capital measure that combines receivable days and inventory days minus payable days into one signed accounting cycle.
Cash-flow-to-debt ratio	Corporate Finance and Credit Analysis	A solvency ratio dividing a defined operating cash-flow measure by a defined total debt balance to indicate cash generation relative to leverage.
Catastrophe Modeling	InsuranceCatastrophe Risk Modeling	A loss-estimation method that connects severe-event hazards, exposed assets, damage vulnerability, and financial terms to portfolio loss scenarios or distributions.
Catch-up effect	Growth EconomicsDevelopment Economics	The catch-up effect is the conditional-convergence hypothesis that economies starting with lower income per person can grow faster than richer economies when structural determinants of their long-run steady states are comparable.
Centipede Game	Finite Horizon Cooperation Unravelling	A sequential finite-horizon game in which each player can take the larger share or pass to grow the pot, where backward induction prescribes taking on the first move — isolating common knowledge of rationality as the load-bearing assumption cooperation depends on.
Chamberlinian monopolistic competition	Industrial OrganizationMarket Structure	One example where Chamberlinian monopolistic competition can be experienced is the book market.
Chance-constrained portfolio selection	Financial Optimization	A portfolio optimization model that maximizes a return objective while limiting the probability that final wealth or another outcome falls below a declared safety threshold.
Chicken Game	Game Theory	A two-player payoff structure (DC > CC > CD > DD) where each side prefers the other to yield and mutual non-yielding is catastrophic but off-path, so the strategic question is not what to play but which asymmetric equilibrium gets selected — resolved by whoever can most credibly and irreversibly commit first.
Chow Test	EconometricsLinear Regression Structural Change Testing	A classical linear-model F-test that asks whether one coefficient vector can govern two prespecified subsamples by comparing a pooled restricted fit with separate unrestricted fits.
Circular Cumulative Causation	Development EconomicsRegional Economics	A social or economic feedback process in which linked changes reinforce a development path over successive rounds.
Circular Flow	Macroeconomics Intro	Represent the whole economy as two loops running opposite ways between households and firms, then track every off-loop flow as a leakage or an injection whose sums must balance when the loop closes in steady state.
Closed-household economy	Economic HistoryHistorical School Economics	A closed-household economy is a society's economic system in which goods are not traded.
Club Good	Public Economics	Classify a shared resource as excludable-and-non-rival-up-to-congestion, which fixes that it can be provided privately by membership fee, and select its pricing regime by which side of the congestion threshold it sits on.
Coase Theorem	Law and Economics	State that with clear property rights and zero transaction costs, parties bargain to the same efficient allocation whatever the initial assignment — so the assignment fixes only who pays whom, and observed inefficiency is read contrapositively as the signature of a specific friction.
Cobweb Model	Market Dynamics	The economic model of self-sustaining price-quantity oscillation in markets with a rigid production lag, where producers commit output on today's price and discover it clears at another — tracing a cobweb spiral whose stability follows from the supply-to-demand slope ratio.
Cognitive Hierarchy Theory	Behavioral Game Theory	Predict strategic play by mixing reasoning-depth types whose positive levels best respond to beliefs over all strictly lower levels.
Collateral Squeeze	Financial Stability and Credit	The procyclical spiral in which a fall in a pledged asset's price cuts every leveraged holder's borrowing capacity and forces sales into the same market that sets the price — coupling firms through a shared observable rather than a counterparty network.
Collectible market index	Alternative Asset IndicesPrice Indices	An index aggregating observed or estimated prices for a defined segment of collectible assets relative to a base date in order to track market-value change over time.
Common-Pool Resource	Public Economics	The taxonomy cell for a good that is rival yet non-excludable — a conjunction that opens an appropriability gap between private and social cost, switching on the overuse dynamic and posing a three-way governance choice: privatize, regulate, or self-govern.
Compensation principle	Welfare Economics	A welfare-economic decision rule favoring a change when its gainers could hypothetically compensate its losers and still retain a gain.
Competitive Equilibrium	General Equilibrium Theory	A price vector and feasible allocation at which consumers and firms optimize given prices and every market clears simultaneously.
Composite Good	Consumer TheoryMicroeconomics	In economics, a composite good is an abstraction that represents all but one of the goods in the relevant budget.
Concentration Illusion	Portfolio Construction and Risk Management	The failure where a portfolio looks diversified across many labels but its holdings share a hidden common factor — so a single shock moves them together and realized risk tracks the rank of the factor-exposure matrix, not the count of positions.
Conjectural variation	Industrial OrganizationOligopoly Theory	In oligopoly theory, conjectural variation is the belief that one firm has an idea about the way its competitors may react if it varies its output or price.
Consumer leverage ratio	Household Finance	The ratio of household debt outstanding to annual disposable personal income for a matched population and period.
Consumer price index	Official Statistics and Price Measurement	A periodically updated weighted index estimating price change for a defined basket of household consumption goods and services relative to a reference period or chain.
Consumer Surplus	Microeconomics	The aggregate welfare buyers gain by paying a market price below what each would have been willing to pay, measured as the area between the demand curve and the price line — giving voluntary exchange's buyer-side value a monetary magnitude for welfare analysis.
Consumption Rivalry	Public EconomicsResource Economics	Test whether one consumer's use of a specified economic benefit subtracts from what another can use, under stated time and capacity conditions.
Contestable Market	Industrial Organization	Diagnose market power from entry conditions rather than firm count — where entry and exit are costless, the mere credible threat of hit-and-run entry disciplines even a monopolist to competitive pricing, so the binding variable is sunk cost, not concentration.
Contract curve	Microeconomics	The locus of Pareto-efficient allocations in an Edgeworth box where the two consumers’ indifference curves are tangent or a boundary constraint binds.
Convergence (economics)	Economic Growth and Development	The hypothesis or observed tendency for initially poorer economies to grow faster than richer ones and thereby narrow differences in per-capita income or productivity.
Convergence clubs	Development Economics	Groups of economies whose declared development indicators converge toward a shared long-run path or level within each group while remaining separated from other groups.
Coordination good	Civil Society EconomicsPublic Goods Theory	A largely non-rival good whose value is created or amplified by coordinated participation, with access sometimes limited by withholding cooperation from nonparticipants.
Correlated equilibrium	Game Theory	A joint distribution over players' action recommendations such that, conditional on each private recommendation, no player gains by unilaterally remapping their action.
Cost-Weighted Activity Index	Official StatisticsNon Market Output MeasurementNational Accounts	A nonmarket output-volume index that aggregates changes in homogeneous service activities using base-period cost shares or unit costs as weights.
Costly state verification	Contract Theory	A contract-theory framework in which an informed borrower privately observes project return and an uninformed financier must pay to verify it.
Cox–Ingersoll–Ross model	Mathematical FinanceShort Rate Models	A mean-reverting square-root diffusion for a nonnegative short interest rate, supporting affine bond pricing and volatility proportional to the square root of the rate.
Credence good	Information Economics	A good or service whose important quality is difficult or costly for consumers to evaluate even after purchase and consumption.
Credibility thesis	Institutional Economics	A thesis that institutions evolve endogenously and persist when their function is socially credible rather than because they match original design.
Credit channel	Monetary EconomicsMonetary Policy Transmission	Explain how monetary-policy impulses are amplified when financial frictions change borrowers' external-finance premiums or banks' supply of intermediated credit, altering spending beyond the conventional interest-rate channel.
Credit rationing	Credit Markets and Information Asymmetry	Restrict the quantity of lending available to some observationally willing borrowers at the quoted terms because information, incentives, risk, or institutional constraints prevent price alone from clearing the credit market.
Cross Elasticity of Demand	Microeconomics	The unit-free ratio of the percentage change in one good's quantity demanded to the percentage change in another good's price — whose sign classifies goods as substitutes, complements, or independent and whose magnitude ranks how tightly they constrain each other's prices.
Crowding In	Public Finance Macroeconomics	The macroeconomic pattern in which public expenditure raises rather than displaces private investment — the sign reversal of crowding out — obtained when the economy has slack and the public input complements private activity, through a demand channel or a complementarity channel.
Currency	Monetary Systems	A currency is an institutionally recognized system of monetary units together with the tokens, account balances, or records denominated in those units and accepted within a scope for pricing, payment, settlement, and monetary accounting.
Currency crisis	International Macroeconomics	A financial crisis in which confidence in a currency or exchange-rate regime collapses, producing abrupt depreciation, reserve loss, forced devaluation or abandonment of a peg.
Current Ratio	Financial Statement Analysis	Measure balance-sheet liquidity at a reporting date as current assets divided by current liabilities, interpreted through asset convertibility, liability timing, seasonality, and industry operating cycles.
Cyclically adjusted price-to-earnings ratio	Equity ValuationFinancial Economics	The cyclically adjusted price-to-earnings ratio (CAPE, Shiller P/E, or P/E 10 ratio) is a stock valuation measure usually applied to the US S&P 500 equity market.
Debt Overhang	Corporate Finance	The condition where existing senior debt is so large that a new project's upside flows first to old creditors, so the residual claimant rationally declines even positive-NPV investment — the cure being to reorder the payoff cascade until the needed party can capture enough to participate.
Debt service coverage ratio	Corporate FinanceCredit Analysis	The debt service coverage ratio (DSCR), also known as the debt coverage ratio (DCR), is a financial ratio that measures an entity's ability to generate sufficient cash to cover its debt obligations, including interest, principal, and lease payments.
Debt service ratio	International Finance	A country-level ratio of external principal and interest payments to export earnings over the same period.
Debt-to-income ratio	Consumer Finance	The proportion of a consumer's gross monthly income committed to recurring debt and specified housing payments.
Decartelization	Competition PolicyPolitical Economy	The policy-driven dismantling of cartelized or monopoly-concentrated economic control through prohibition of collusion, breakup or deconcentration, entry measures, and institutional reforms intended to restore competitive decision making.
Deflation	Monetary Macroeconomics	A sustained, broad-based fall in the general price level whose policy-critical content is the debt-deflation spiral — falling prices raise the real burden of fixed nominal debts, forcing distress selling and spending cuts that push prices down further when the monetary stabiliser is bounded.
Deleveraging	Corporate FinanceMacrofinance	At the micro-economic level, deleveraging refers to the reduction of the leverage ratio, or the percentage of debt in the balance sheet of a single economic entity, such as a household or a firm.
Demand curve	Microeconomics	A ceteris-paribus price–quantity representation for a specified good and buyer population, distinguishing movement from nonprice-induced shifts.
Demand Shaping	Supply Chain Management	The supply-chain practice of applying pricing, promotion, substitution, and channel levers to the consumer side of a capacity mismatch — moving realized demand toward feasible supply rather than scaling supply to meet it — by steering the marginal consumer's selection.
Demand Shock	Macroeconomics	An unanticipated or externally driven shift in desired spending that moves demand at prevailing prices, raising or lowering output and price pressure relative to baseline according to persistence, slack, expectations, and policy response.
Demerit good	Public Economics	A good judged to be overconsumed because consumers undervalue harms to themselves, motivating paternalistic taxation, regulation, or information policy.
Dependency theory	Development Studies	A development theory arguing that peripheral economies are structurally constrained and impoverished by their unequal integration into a core-dominated world economy.
Deposit Concentration Risk	Bank Funding and Liquidity	Judge a bank's funding fragility by the correlation-adjusted effective depositor count rather than the headline number — coupled depositors collapse toward one bet, voiding the law-of-large-numbers smoothing a large base seems to guarantee.
Differentiated Bertrand competition	Industrial OrganizationOligopoly Theory	Differentiated Bertrand competition is a price-setting model in which firms sell imperfect substitutes, so each firm's demand depends on its own price and those of its rivals.
Discount function	Intertemporal Choice	Map delay to a present weight applied to future utility, payoff, or value, making timing assumptions explicit and distinguishing exponential consistency from nonexponential patterns.
Disintermediation	Market IntermediationDistribution Channels	Reroute an economic flow away from a specified incumbent intermediary layer without implying that every intermediation function disappears.
Disposition Effect	Behavioral Finance	Explain why investors sell winners too early and cling to losers: the purchase price is a reference point, so gains sit in the concave risk-averse domain of the prospect-theory value function and losses in the convex risk-seeking one, measured as the PGR minus PLR gap.
Distributed lag	Econometrics	A time-series regression structure in which the current response depends on present and multiple lagged values of an explanatory variable through a lag-weight sequence.
Distributive Efficiency	Utilitarian Distribution	Distributive efficiency in Lerner-style welfare economics allocates a fixed income stock to maximize a stated, interpersonally comparable welfare criterion.
Dividend discount model	Equity ValuationAsset Pricing	An equity-valuation model that prices a share as the present value of expected future dividends discounted at the required return.
Divisia Index	Index Number Theory	A continuous-time economic index whose logarithmic growth rate is a current value-share-weighted sum of component quantity or price growth rates, with discrete data ordinarily implemented through superlative approximations such as Törnqvist or Fisher indexes.
Domestic Liability Dollarization	Banking and Currency Mismatch	The denomination of domestic banking-system deposits and loans in a foreign hard currency, creating balance-sheet dependence on a unit of account not controlled by the home monetary authority.
Dominant Strategy	Game Theory	An action that yields a payoff at least as high as any alternative regardless of what opponents choose, so the player needs no model of the others — a belief-free best response that makes the strategic problem collapse to a row-by-row dominance check on the payoff matrix.
Donchian Channel	Technical AnalysisTrading Indicators	The Donchian channel is an indicator used in market trading developed by Richard Donchian.
Double Coincidence of Wants	Monetary Economics and Barter	The two-sided matching requirement that makes direct barter expensive — each trader must simultaneously hold what the other wants and want what the other holds — whose probability falls as goods diversify, motivating a commonly accepted medium that splits each two-sided match into two one-sided sell-then-buy problems.
Double Marginalization	Industrial Organization and Vertical Pricing	Explain why a chain of firms each holding pricing power ends up charging more and selling less than a single integrated firm would, because each node adds its markup while ignoring the demand-shrinking externality that markup imposes on the other node's profit base.
Driver Safety Arms Race	Transport EconomicsRoad SafetyExternalities	The driver-safety arms race is a prisoner's-dilemma dynamic in which individually protective vehicle enlargement makes the fleet progressively larger and collectively more dangerous.
Dumb agent theory	Market EfficiencyInformation Aggregation	A hypothesis that aggregating many independent, individually limited market judgments can estimate value or forecast outcomes better than relying on one purported expert, under conditions that preserve diverse information and incentives.
Duopsony	Industrial OrganizationMarket Structure	A procurement market dominated by two strategic buyers whose concentrated demand and suppliers’ limited outside options confer material power over purchase prices, quantities, or contract terms.
Durbin–Wu–Hausman test	EconometricsSpecification Testing	The Durbin–Wu–Hausman test (also called Hausman specification test) is a statistical hypothesis test in econometrics named after James Durbin, De-Min Wu, and Jerry A.
Dutch Disease	International Trade	Trace how a boom in one tradable sector hollows out the others by running a foreign-exchange windfall through two channels — a spending effect that appreciates the real exchange rate and a resource-movement effect that bids up factor costs — so that headline GDP rises while non-booming tradables de-industrialize.
Easterlin Paradox	Subjective Wellbeing Economics	Reconcile the puzzle that richer people report more happiness at any moment yet national well-being stays flat as real income multiplies over decades — by recognising the cross-sectional gradient reflects relative income against a moving reference, not absolute income.
Economic Complexity Index	Economic ComplexityDevelopment Economics	A model-based index inferring the productive capabilities of a location from the diversity and ubiquity pattern of its economic activities, commonly exports.
Economic Growth Model	Macroeconomic Growth Theory	Represent an economy's long-run output path as a closed dynamic system of productive stocks, accumulation and depreciation, production returns, population or labor, and technology, so assumptions determine whether growth converges, balances on a knife-edge, or sustains itself endogenously.
Economic opportunism	Institutional Economics	Self-interested economic conduct that exploits incomplete rules, information asymmetry or bargaining vulnerability through deception, strategic withholding or norm evasion.
Economic Overheating	Macroeconomics	A macroeconomic state in which aggregate demand or activity presses against sustainable economy-wide productive capacity over a stated horizon.
Economic System	Comparative Economic SystemsInstitutional Economics	An organized institutional arrangement through which a community coordinates production, resource allocation, exchange, distribution, consumption, property, and labor across interdependent actors.
Ecosystem valuation	Ecological EconomicsEcosystem Services Valuation	Estimate monetary, biophysical, or deliberative values for ecosystems and their services so policy comparisons expose benefits, tradeoffs, distribution, uncertainty, and value judgments that markets omit.
Edgeworth Box	MicroeconomicsTwo Person Exchange Economies	Represent every feasible allocation of two fixed goods between two consumers in one reciprocal-coordinate rectangle, then overlay both preference maps to diagnose gains from trade, Pareto efficiency, and competitive equilibrium.
Edgeworth Paradox	Oligopoly Theory	Show that Bertrand's price-equals-marginal-cost result collapses once firms face capacity constraints below total demand: no pure-strategy equilibrium exists and prices cycle endlessly between the competitive floor and monopoly ceiling.
Edgeworth's limit theorem	General Equilibrium Economics	Edgeworth's limit theorem is an economic theorem, named after Francis Ysidro Edgeworth, stating that the core of an economy shrinks to the set of Walrasian equilibria as the number of agents increases to infinity.
Effective exchange rate index	International Economics	An index of a currency’s value against a weighted basket of trading-partner or competitor currencies relative to a base period.
Efficient envy-free division	Fair Division	A resource allocation that is both Pareto efficient and envy-free, so no feasible change benefits someone without harming another and no agent prefers another’s bundle to their own.
Elasticity of complementarity	Production TheoryFactor Substitution	The percentage responsiveness of the ratio of two factors' marginal products or prices to a one-percent change in their relative input quantities, equal under the stated two-factor conditions to the inverse of elasticity of substitution.
Elasticity of intertemporal substitution	MacroeconomicsConsumption Theory	In economics, elasticity of intertemporal substitution (or intertemporal elasticity of substitution, EIS, IES) is a measure of responsiveness of the growth rate of consumption to the real interest rate.
Elliott Wave Principle	Technical Analysis	Interpret market-price charts through a recursively nested taxonomy of motive and corrective wave counts, while treating every count as a revisable reading rather than established predictive evidence.
Ellsberg Paradox	Decision Theory Under Uncertainty	Show that people prefer betting on a known-composition urn over an ambiguous one of equal expected value on both colors at once — a pattern no single subjective probability can rationalize — proving ambiguity is a separately priced dimension of uncertainty distinct from risk.
Employment Arrangement	Labor EconomicsEmployment Arrangements	An employment arrangement is a legally, economically, and organizationally structured relation for obtaining labor that allocates task scope, control, duration, compensation, benefits, termination, liability, and risk among a worker, employer, customer, platform, or intermediary under a governing jurisdiction.
Endogenous Growth Theory	Growth Theory	The class of models that make long-run growth an output of the economy's own agents and incentives rather than an exogenous parameter — the non-rivalry of knowledge generating aggregate increasing returns that escape diminishing-returns convergence and turn R&D and IP policy into growth levers.
Endowment Effect	Behavioural Economics	Explain why the same person prices the same good higher once they own it — willingness-to-accept running two-to-five times willingness-to-pay — by acquisition shifting the reference point to include the good, so parting with it registers as a loss that loss aversion over-weights.
Engel curve	Consumer Demand	Read a good's economic character — normal or inferior, necessity or luxury — off the slope and curvature of a single schedule that plots its consumption against household income while holding all prices fixed.
Entrepreneurial Discovery	Austrian Economics	Explain how markets correct their own disequilibria — alert agents perceive profit gaps that others overlook and are not yet in anyone's search space, act on them, and thereby arbitrage the gaps away, an endogenous error-correction no central planner could replicate.
Entrepreneurship	Business and EconomicsEntrepreneurship Studies	Committed action under uncertainty that forms or reconfigures a venture to create or expand economic, social, or cultural value through new products, processes, markets, or organizational arrangements.
Environmental Kuznets curve	Environmental Economics	The hypothesis that environmental degradation follows an inverted-U against per-capita income — rising as a poor economy industrializes, peaking at middle income, then falling as richer populations buy cleaner technique — holding only for local, internalized pollutants, not global-commons ones.
Envy ratio	Private Equity	The ratio of institutional investors' price per equity percentage point to management's price per equity percentage point in a buyout.
Equity premium puzzle	Asset Pricing	Confront one number against one model — the ~6-point historical equity premium against what a consumption-CAPM with plausible risk aversion can rationalize — and read the order-of-magnitude miss as indicting a load-bearing assumption in an enumerable stack.
EV/EBITDA	Equity ValuationCorporate Finance	EV/EBITDA is a valuation multiple dividing enterprise value by earnings before interest, taxes, depreciation, and amortization to compare the market value of operating businesses across financing and accounting structures.
EV/GCI	Corporate Valuation and Croci Analysis	An enterprise-basis valuation multiple dividing enterprise value by gross cash invested, read as the market value assigned per unit of cumulative operating capital within CROCI-style returns analysis.
Exchange economy	MicroeconomicsGeneral Equilibrium Theory	A microeconomic model in which agents trade endowed goods through a price system, with pure exchange excluding production and production-exchange variants adding firms and transformation of goods.
Exchange rate	International FinanceForeign Exchange	The quoted price at which one currency can be exchanged for another, expressed as units of a quote currency per unit of a base currency under a specified market, time, and transaction convention.
Excludability	Public Economics	Classify a good by whether non-payers can feasibly be kept from consuming it, and cross that with rivalry to place it in the four-cell Samuelsonian map — private, club, common-pool, public — each cell carrying its own provision pathology and remedy.
Expected-return allocation under rationed premium employment	Labor Economics	Model how access to a rationed premium job changes with applicant crowding and shapes entry between labor alternatives.
Expenditure function	Microeconomic Consumer Theory	The minimum spending needed at given prices to attain a specified utility level.
Experience Good	Information EconomicsIndustrial Organization	An experience good is a product or service whose relevant quality can be evaluated accurately only after it has been purchased and experienced.
Extended Sympathy	Social Choice and Welfare EconomicsInterpersonal Comparison	An interpersonal evaluative ordering over person–state pairs that ranks one person's situation in one social state against another person's situation in another, expanding welfare analysis beyond separate individual preferences.
Factor cost	National Accounts	A valuation of production or national output at the payments to factors of production, excluding indirect taxes and adding subsidies rather than using purchasers' market prices.
Fair Division	Fair DivisionMechanism Design	The formal allocation problem of assigning goods or burdens among agents under an explicitly stated fairness criterion and feasible-share constraints.
Faustmann's formula	Forest Economics	The rotation problem, deciding when to cut down the forest, means solving the problem of maximising Faustmann's formula and this was solved by Bertil Ohlin in 1921 to become the Faustmann-Ohlin theorem, although other German foresters were aware of the correct solution in 1860.
Feasibility condition	Consumer TheoryMicroeconomics	The feasibility condition is a fundamental concept in microeconomics used in conjunction with the tangency condition to solve the consumer choice problem and derive the demand function.
Feldman–Mahalanobis model	Development Economics	A two-sector development model prioritizing investment in capital-goods capacity to raise the long-run ability to produce both capital and consumer goods.
Feldstein-Horioka Puzzle	International Macroeconomics	The anomaly that national saving and investment rates are strongly correlated across countries when frictionless capital mobility predicts near-zero — turning the regression slope into a continuous gauge of de facto capital-market integration.
Financial Accelerator	Macroeconomics and Credit Cycles	The credit-market feedback loop by which a modest shock is amplified — falling asset prices erode collateral, raising the external-finance premium, which cuts investment and depresses prices further — its whole strength read off one elasticity: the premium's sensitivity to borrower net worth.
Financial network	Financial NetworksNetwork Economics	A financial network is a concept describing any collection of financial entities (such as payment card companies, firms, banks and financial transaction processing) and the links between them, ideally through direct transactions or the ability to mediate a transaction.
Financial Repression	Financial Regulation	A policy configuration that channels domestic savings toward favored borrowers through paired return restraints and captive financing rules.
Fiscal Gap	Long Term Fiscal ProjectionFiscal Sustainability	A conditional measure of the sustained revenue or spending adjustment needed to meet a declared long-run government fiscal target under a specified projection.
Fiscal Illusion	Public Finance	The public-finance phenomenon in which a financing mechanism obscures the price signal linking public goods to their cost, so taxpayers underperceive the true burden — biasing demand for public spending upward relative to what fully-informed citizens would choose.
Fiscal Multiplier	Macroeconomics	Compress a fiscal impulse's whole propagation cascade into one estimable ratio — the change in aggregate output over the change in government spending or taxation — driven by the marginal propensity to consume through induced rounds of income, less leakages and offset channels, and conditioned on regime.
FISIM	National Accounts	In the System of National Accounts it is an estimate of the value of the services provided by financial intermediaries, such as banks, for which no explicit charges are made; instead these services are paid for as part of the margin between rates applied to savers and borrowers.
Fixed-Effects Estimator	Panel Data EconometricsEconometrics	In panel data analysis the term fixed effects estimator (also known as the within estimator) is used to refer to an estimator for the coefficients in the regression model including those fixed effects (one time-invariant intercept for each subject).
Flight to Quality	Financial Markets	Read a scatter of cross-asset crisis moves as one event with one direction — capital fleeing toward the safe end of the risk spectrum — driven by a self-reinforcing amplification loop that safe-asset provision is designed to break.
Flow of funds	National AccountsFlow of Funds Accounting	Flow of funds accounts are a system of interrelated balance sheets for a nation, calculated periodically.
Folk Theorem (Repeated Games)	Game Theory	Show that in a sufficiently long, patiently discounted repeated game, almost any mutually acceptable outcome can be held as an equilibrium by credible intertemporal punishment — so repetition both explains cooperation and destroys predictive determinacy.
Forced saving	MacroeconomicsShortage Economics	An involuntary gap between household income and current consumption caused by goods shortages, unaffordable prices, or credit constraints rather than by a voluntary plan to defer consumption.
Forward measure	Mathematical FinanceDerivative Pricing	In finance, a T-forward measure is a pricing measure equivalent to a risk-neutral measure, but rather than using the money market as numeraire, it uses a bond with maturity T.
Foster–Greer–Thorbecke Poverty Measures	Development EconomicsPoverty Measurement	A parameterized family of poverty measures averaging powered, normalized welfare shortfalls below a line, with additive subgroup decomposition.
Fractional Pareto efficiency	Fair Division	A discrete allocation is fractionally Pareto-efficient when no feasible allocation, including fractional ones, can make every agent at least as well off and one strictly better off.
Fractional Response Model	Fractional Response	A fractional response model estimates how covariates change the conditional mean of a proportion in [0,1] through a bounded link, retaining exact zero and one observations.
Fractional-Reserve Banking	Monetary EconomicsBanking	A banking system in which deposit-taking banks hold only part of their deposit liabilities in liquid reserves while investing or lending the remainder under monetary and prudential constraints.
Friedman Rule	Monetary Policy and Macroeconomics	Set the nominal interest rate to zero — via a steady deflation at the real rate — so that the private opportunity cost of holding money equals its near-zero social cost of production, eliminating the shoe-leather distortion; a benchmark that isolates one welfare cost and prices money at marginal cost.
Friedman–Savage utility function	Decision Theory	A wealth-dependent expected-utility curve with alternating concave and convex regions intended to explain simultaneous insurance purchase and lottery play.
Full employment	Macroeconomics	A macroeconomic condition in which employment is as high as sustainably attainable, allowing frictional and structural unemployment but no material deficient-demand unemployment.
Functional Finance	Macroeconomic PolicyPublic FinanceMonetary Economics	A macroeconomic policy doctrine that judges sovereign fiscal and monetary operations by their effects on employment, inflation, output, and interest conditions rather than by budget balance as an end in itself.
Funding Fragility	Financial Stability Systemic Risk	The condition in which an entity depends on short, revocable, confidence-sensitive financing to sustain long, illiquid positions, so that the same balance sheet supports both a continued-funding equilibrium and a self-fulfilling run equilibrium — and can be killed while technically solvent.
FWL theorem	EconometricsLinear Regression	An ordinary-least-squares equivalence stating that a regressor's coefficient equals the coefficient obtained after residualizing both the outcome and that regressor against the other included regressors.
Gambling	Gambling StudiesDecision Under Risk	Gambling (also known as betting or gaming) is the wagering of something of value ("the stakes") on a random event with the intent of winning something else of value, where instances of strategy are discounted.
General equilibrium theory	Microeconomic TheoryGeneral Equilibrium	An economic framework that solves for mutually compatible prices, production, and allocations across all modeled markets by imposing agent optimization and simultaneous market clearing.
Generalized entropy index	Inequality Measurement	A parameterized family of decomposable inequality measures computed from powers or logarithms of each observation's ratio to the population mean.
Generalized Ozaki cost function	Production EconomicsCost Functions	In economics the generalized-Ozaki (GO) cost function is a general description of the cost of production proposed by Shinichiro Nakamura.
Generational Accounting	Public Finance	Project each birth cohort's net public fiscal flows within a declared government or program boundary and discount them to a common date.
Gibbard's theorem	Social Choice TheoryMechanism Design	In the fields of mechanism design and social choice theory, Gibbard's theorem is a result proven by philosopher Allan Gibbard in 1973.
Gibrat's Law	Industrial Organization and Firm Dynamics	The claim that a firm's proportional growth rate is independent of its current size — which, iterated as multiplicative iid noise, makes log-size a random walk and drives the cross-sectional size distribution toward log-normal.
Gibson's Paradox	Monetary Economics and Macro History	The gold-standard-era regularity that long-term nominal interest rates tracked the price level itself, not the rate of inflation — a Fisher-violating correlation that vanished under fiat money, marking it a regime-specific artifact rather than a law.
Giffen Good	Microeconomic Theory Consumer Demand	A good whose quantity demanded rises as its own price rises — the rare case where a good is inferior and its income effect outweighs its substitution effect, flipping the Marshallian demand curve upward in apparent violation of the law of demand.
Gig economy	Labor EconomicsPlatform Economy	A labor-market arrangement in which organizations or customers purchase bounded tasks or short engagements from workers—often mediated and governed by digital platforms—rather than providing continuous standard employment.
Gini Coefficient	Inequality and Distributional Measurement	Collapse a whole distribution of a resource into one number on a 0-to-1 scale by measuring how far its Lorenz curve bows away from perfect equality.
Global Games	Game Theory and Equilibrium Selection	Pick a single prediction out of a coordination game's many self-fulfilling equilibria by giving each player a private noisy signal of a common fundamental and deleting dominated strategies inward until one threshold cutoff survives.
Gold points	Monetary EconomicsGold Standard Exchange	The upper and lower exchange-rate bounds under the gold standard at which the cost of settling by shipping gold became cheaper than buying or selling foreign bills.
Golden Rule Savings Rate	Macroeconomic Growth Theory	Pin the savings rate that maximizes steady-state per-capita consumption at the capital stock where the marginal product of capital equals population growth plus depreciation (f'(k*) = n + δ) — turning savings-policy welfare into a single scalar sign test.
Gompertz–Makeham Law of Mortality	—	An adult-lifetime model decomposes instantaneous mortality into an age-independent Makeham hazard plus a Gompertz hazard that rises exponentially with age.
Government Failure	Public Economics	The patterned ways government intervention produces outcomes worse than the market failure it meant to correct, derived by modeling the state as self-interested actors under institutional constraints — capture, rent-seeking, electoral myopia, bureaucratic bloat — and set symmetrically against market failure on one comparative surface.
Greater Fool Theory	Speculative Markets	The transaction logic in which a buyer knowingly pays above what they judge an asset is worth, betting purely on a higher-paying successor before they must exit — individually rational under a long enough mania, yet collectively self-terminating once the supply of willing buyers is exhausted.
Greenwald-Stiglitz theorem	Information EconomicsWelfare Economics	The Greenwald-Stiglitz theorem shows that an economy with externalities or distortions associated with imperfect information and incomplete markets is in general not constrained Pareto optimal, and there exist government interventions such as taxes and subsidies to make a Pareto improvement.
Gross Household Product	Household EconomicsNational Accounting	Gross Household Product is a recurring household economics, national accounting identity in which unpaid household labor and household capital are valued to estimate household-sector economic production omitted from conventional accounts.
Gross national product	National AccountingMacroeconomics	The former production-framed name for gross national income: the gross primary income attributable to a country's residents, equal to GDP plus residents' factor income from abroad minus factor income paid to nonresidents.
Gross Value Added	National Accounts	Measure a producer's output minus intermediate consumption, then aggregate contributions under national-account valuation rules.
Growth elasticity of poverty	Development EconomicsPoverty Analysis	Growth elasticity of poverty (GEP) is the percentage reduction in poverty rates associated with a percentage change in mean (per capita) income.
Growth Recession	MacroeconomicsBusiness Cycles	A period of positive but sub-threshold real economic growth in which output expands too slowly to stabilize employment, so unemployment or labor-market slack rises without an ordinary output recession.
Habakkuk Thesis	Economic History	The Habakkuk thesis, proposed and named after British economist Sir John Habakkuk, is a theory that land abundance and labor scarcity in antebellum America led to high wages, which resulted in effective searches for labor-saving technological innovations.
Hahn's problem	Monetary TheoryGeneral Equilibrium Theory	Hahn's problem (or Hahn's question) refers to the theoretical challenge of building general equilibrium models where money does not enter preferences, yet has a positive equilibrium value.
Harrod-Domar Model	Macroeconomics and Growth Theory	Estimate an economy's sustainable growth rate as its savings rate divided by its capital-output ratio (g = s/v), giving a two-lever policy arithmetic and exposing a knife-edge equilibrium with no mechanism to return the economy to its warranted path.
Hawk–Dove Game	Game Theory and Evolutionary Dynamics	Model an anti-coordination contest with mutually destructive escalation as a 2x2 game whose entire equilibrium is fixed by the cost-to-prize ratio V/C — predicting a structural, tunable rate of costly conflict among fully rational players who would all prefer peace.
Heckman correction	EconometricsSample Selection Models	A two-step or full-likelihood econometric method that models sample selection and adds the implied inverse Mills ratio to correct outcome estimates under joint-normality assumptions.
Heckscher–Ohlin Model	International Trade TheoryGeneral Equilibrium	A general-equilibrium trade model in which countries export goods that intensively use their relatively abundant factors and import goods intensive in relatively scarce factors, conditional on the model's maintained assumptions.
Hedonic regression	Hedonic Price Models	Regress the price or rent of a differentiated good on its characteristics to estimate an implicit price surface and, with additional assumptions, demand or welfare effects.
Heteroskedasticity-consistent standard errors	EconometricsRobust Covariance Estimation	Regression standard-error estimators using a sandwich covariance formula that remains asymptotically valid when error variance differs across observations under independence and regularity conditions.
Hicksian demand function	Microeconomic Consumer Theory	A compensated demand function giving expenditure-minimizing quantities at prices while holding utility fixed.
Hierarchical Risk Parity	Portfolio Construction	Allocates asset weights by clustering return behavior, ordering assets by the tree, then recursively splitting weight between branches by their estimated variances.
Hold-up Problem	Transaction Cost Economics	Explain why parties who would both gain from a relationship-specific asset fail to build it: once the investment is sunk the counterparty can renegotiate against the exposed investor, and it is the anticipation of that squeeze — not the squeeze itself — that quietly distorts investment beforehand.
Holdout Problem	Bargaining and Collective Action	The bargaining failure in which a complementary surplus requiring unanimous consent lets any pivotal, non-substitutable party refuse agreement and extract a disproportionate share as the price of consent — making rational extraction, not bad faith, the equilibrium.
Home bias in trade puzzle	International EconomicsGravity Models and Border Effects	The empirical finding that otherwise comparable regions trade far more within national borders than across them, leaving a large border effect after distance, size and standard gravity-model determinants are controlled.
Hoover index	Inequality Measurement	An inequality measure equal to the share of total income or another resource that would need redistribution to achieve equal per-capita shares.
Horizontal Integration	Corporate StrategyIndustrial Organization	Bringing activities at the same business-chain stage under common firm control.
Horizontalism	Monetary EconomicsEndogenous Money	A post-Keynesian theory of endogenous money in which bank lending creates deposits and central banks accommodate the resulting reserve demand at a policy-controlled interest rate.
Hotelling's Law	Industrial Organization	The result that two share-maximizing suppliers competing for uniformly distributed consumers who patronize the nearest provider converge on minimum differentiation — both clustering at the median — a share-maximizing yet welfare-minimizing equilibrium whose predictions shift in signed directions as its base-case assumptions are relaxed.
Hotelling's Rule	Natural Resource Economics	Treat an unextracted unit of a nonrenewable resource as a non-dividend asset, and require its net price — spot price minus marginal extraction cost — to compound at the interest rate, so the owner is indifferent between extracting now and holding for later.
Household electricity approach	Shadow Economy MeasurementMacroeconomic Measurement	An indirect macroeconomic method that estimates a country's hidden economy from excess household electricity use relative to modeled official activity and other observable determinants.
Household production function	Household EconomicsNew Home Economics	A household production function models how households combine purchased commodities with time and skills to produce the services or final goods from which they derive utility.
Housing Affordability Index	Housing Affordability Measurement	A normalized indicator that compares a defined household's income or purchasing capacity with the housing costs of a defined dwelling or market, making affordability trends and geographic differences legible only under explicit financing, tenure, cost, and population assumptions.
Human Capital	Labor and Development Economics	Treat the knowledge, skills, experience, and health embodied in people as an investable capital stock — with a cost, a discounted return stream, and a depreciation rate — so schooling and health spending become commensurable investments rather than consumption.
Immiserizing growth	International Economics	A trade-theoretic case in which output growth worsens a large exporting country’s terms of trade enough to reduce national welfare.
Import ratio	International Economics and Sovereign Risk	A sovereign-liquidity indicator comparing a country's imports with its foreign-exchange reserves, commonly expressed as imports divided by reserves or as months of import cover.
Import Replacement	Urban Economic Development	City enterprises locally produce goods formerly imported, expanding production capabilities.
Impossible Trinity	International Macroeconomics	A monetary authority can hold at most two of a fixed exchange rate, free capital mobility, and independent monetary policy because interest-rate parity and balance-of-payments adjustment make the third a residual.
Imputation (Game Theory)	Cooperative Game Theory	A payoff allocation in a transferable-utility cooperative game that distributes the grand coalition's entire worth while giving every player at least its stand-alone coalition value.
Income Effect	Microeconomic Consumer Theory	Split a consumer's demand response to a price change into the part driven purely by the shift in real purchasing power — separating it from re-optimization toward cheaper substitutes — so a good's Engel-curve slope classifies it as normal, inferior, or Giffen.
Income Elasticity of Demand	Microeconomic Consumer Theory	Collapse a good's whole income-demand relationship into one unit-free ratio of percentage change in quantity to percentage change in income, so its sign and position relative to one classify it as inferior, necessity, or luxury.
Incremental Capital–Output Ratio	Macroeconomics	A period-matched ratio relating capital formation to a change in real output, used cautiously as an investment-intensity indicator or conditional growth-planning parameter.
Index (Economics)	Economic Measurement	A normalized statistic comparing the level or change of a specified economic aggregate across periods, places, or populations relative to a declared base using explicit items, weights, and an aggregation formula.
Industrial Inertia	Economic GeographyIndustrial Location Theory	Geographical industrial inertia is a stage at which an industry prefers to run in its former location although the main alluring factors are gone.
Industrialization	Economic HistoryDevelopment Economics	Industrialisation (UK) or industrialization (US) is "the period of social and economic change that transforms a human group from an agrarian and feudal society into an industrial society.
Inferior Good	Microeconomics Consumer Theory	Classify a good by the sign of its income elasticity: one whose demand falls as income rises (η_Y < 0), because a rising budget lets the consumer shift toward a preferred substitute now within reach — with the Giffen good as its extreme tail.
Inflation	Monetary Economics	Track the shrinking purchasing power of a currency by measuring the annualized percentage change in a weighted price index, isolating the common price movement shared across a basket from the relative-price shifts that carry allocative information.
Informal Economy	Labor and Development Economics	Economic activities by workers and units that are, in law or practice, not covered or insufficiently covered by formal arrangements, spanning both informal enterprises and informal jobs.
Information Avoidance	Epistemic Choice	Actively decline information that is freely available because the anticipated content carries disutility — affective pain, identity threat, or an unwanted obligation — so the resulting non-knowledge is a chosen decision, not an absence.
Information matrix test	EconometricsEconometric Specification Testing	Diagnose parametric likelihood misspecification by testing whether score outer-product and negative expected-Hessian information estimates agree under the fitted model.
Inframarginal analysis	New Classical EconomicsEconomics of Specialization	Inframarginal analysis compares discrete specialization and organizational configurations, solves the local optimum within each feasible corner, and then selects the best configuration including transaction costs.
Inside money and outside money	Monetary Theory	A monetary distinction between privately issued debt money whose asset is matched by an internal issuer liability and money or monetary assets held in net positive amount by the private economy because their counterpart liability lies outside it.
Interest Rate	Monetary Finance	Price the use of money over time as a percentage of principal per period, the single factor that discounts any future cash flow into a present-value equivalent and, through a web of arbitrage conditions, binds every rate in an economy into one coherent system.
Intermediate-Scale Option (the "missing middle")	Regulatory Market Structure	Diagnose a hollowed-out middle of some continuum — building size, price tier, credential level — not as revealed preference for the extremes but as the artefact of a specific removable rule that burdened the intermediate, so the fix is to change the rule rather than serve the extremes.
International trade	International Economics	International trade is the exchange of capital, goods, and services across international borders or territories because there is a need or demand for goods or services.
Intertemporal Equilibrium	Intertemporal Equilibrium TheoryGeneral Equilibrium	A multi-period allocation and price system in which agents' complete dated plans are individually optimal and mutually feasible across time, states, assets, production, and resource constraints.
Inverted yield curve	Fixed IncomeFinancial Markets	In finance, an inverted yield curve is a yield curve in which short-term debt instruments (typically bonds) have a greater yield than longer term bonds.
Invisible balance	Balance of PaymentsInternational Economics	The balance of international receipts and payments for services and other non-goods transactions—such as transport, tourism, consulting, and licensing—contrasted with the visible balance in merchandise trade.
Isovalue lines	Production and Trade Theory	A straight constant-market-value contour in two-good quantity space, defined by V = PₓQₓ + PᵧQᵧ and ordered in a parallel family with slope −Pₓ/Pᵧ at fixed prices.
IS–LM model	Macroeconomics	A two-curve diagram fixing short-run equilibrium in a closed economy: the downward IS curve where the goods market clears and the upward LM curve where the money market clears cross at one point (r*, Y*) that pins down the interest rate and output jointly.
Iterated Prisoner's Dilemma	Game Theory and Strategic Interaction	The prisoner's-dilemma stage game (payoffs T > R > P > S) played over many observed rounds, where a high enough continuation probability lets the threat of future punishment deter present defection — turning the one-shot game's unavoidable mutual defection into sustainable cooperation.
J-Curve Effect	Macroeconomics and International Trade	Explain why a policy's early signal reverses sign — an initial deterioration then a larger, delayed improvement — via a time-elasticity gap between a fast price channel and a slow quantity channel, gated by the Marshall-Lerner condition.
Jensen's alpha	Portfolio Performance EvaluationFinancial Economics	In finance, Jensen's alpha (or Jensen's Performance Index, ex-post alpha) is used to determine the abnormal return of a security or portfolio of securities over the theoretical expected return.
Job creation index	Labor Market IndicatorsLabor Economics	A job creation index is a measure of net hiring of full- and part-time adult workers.
Joint product pricing	Managerial EconomicsPricing	In microeconomics, joint product pricing is the firm's problem of choosing prices for joint product, each of which is considered to be of value.
Jones model	Economic Growth TheorySemi Endogenous Growth	The Jones model (also known as the semi-endogenous growth model) is a growth model developed in 1995 by economist Charles I.
Kakwani Index	Public FinanceTax Progressivity Measurement	A rank-based progressivity measure comparing an intervention's concentration coefficient with pre-intervention income inequality under a declared ranking and sign convention.
Kalai–Smorodinsky Bargaining Solution	Cooperative Bargaining	Select the Pareto-efficient feasible agreement that equalizes each bargainer's gain above disagreement as a proportion of that bargainer's maximum feasible gain.
Kaldor-Hicks Efficiency	Welfare Economics and Cost Benefit Analysis	Judge a policy efficiency-improving if the gainers could in principle fully compensate the losers and still stay ahead, reducing the whole welfare ledger to the sign of one scalar — aggregate willingness-to-pay minus willingness-to-accept — whether or not compensation is paid.
Kenneth Boulding's Evolutionary Perspective	Evolutionary Economics	Boulding's evolutionary perspective is an approach to economics (see also evolutionary economics) put forward most completely in his Ecodynamics (1978) and Evolutionary Economics (1981) had roots in his 1934 work on population theory and the age structure of capital as well as his Reconstruction (1950) with chapter titles like "An Ecological Introduction" and "The Theory of the Economic Organism.".
Kinetic Exchange Models of Markets	Econophysics	Model a market distribution through stochastic pairwise transfers of a declared conserved money or wealth stock.
Knightian uncertainty	Economics of Uncertainty	Uncertainty about outcomes for which no well-grounded probability distribution is available, contrasted with measurable risk.
Knowledge Falsification	Preference and Knowledge FalsificationPolitical Economy	The deliberate public misrepresentation or concealment of one's privately held information, interpretation, or understanding in response to perceived social, economic, or political pressure.
Kondratiev wave	Macroeconomics	The contested hypothesis that capitalist economies exhibit roughly 40-60-year cycles of expansion and contraction, driven by clusters of general-purpose innovations whose diffusion generates a long upswing, saturates, and gives way to a depressive phase in which the next techno-economic paradigm gestates — a heuristic placement ladder more than a predictive model.
KPSS test	Econometrics	A time-series test whose null hypothesis is level or trend stationarity and whose alternative is a unit-root process.
Kuhn's theorem	Game TheoryExtensive Form Games	In game theory, Kuhn's theorem is a foundational result in the analysis of extensive-form games, first formalized by American mathematician Harold W.
Kuznets curve	Development Economics	Read income inequality's response to development as an inverted-U — rising early as a dispersion force (sectoral transition) dominates and falling late as a compression force (skills and redistributive institutions) overtakes it — while checking whether the falling limb is developmental or merely contingent institutions.
Kuznets swing	Macroeconomics	Read a roughly 15-25-year cycle in construction and investment as the interaction of two coupled lags — a slow demographic demand pulse against the multi-year build lag of long-lived capital — placing it as the medium octave between the short business cycle and the long Kondratiev wave.
Laffer curve	Public Finance	Tax revenue is a non-monotone function of the rate — zero at 0% and zero at 100% — so a mechanical effect raising revenue and a behavioural base-erosion effect eroding it produce an interior revenue-maximising peak at rate 1/(1+e).
Law of Demand	Microeconomics	In microeconomics, the law of demand is a fundamental principle which states that there is an inverse relationship between price and quantity demanded.
Law of increasing costs	Production Economics	In economics, the law of increasing costs is a principle that states that to produce an increasing amount of a good a supplier must give up greater and greater amounts of another good.
Law of the handicap of a head start	Economic HistoryTechnological Catch up	A development hypothesis that an early technological or institutional lead can become a later disadvantage when sunk infrastructure and routines impede adoption of superior successor systems.
Legal origins theory	Law and EconomicsComparative Political Economy	Legal origins theory denotes claims that civil law and common law shape lawmaking within law and economics.
Lender of Last Resort	Financial StabilityLiquidity Support	A contingent financial liquidity backstop that supplies bounded residual funding when ordinary refinancing for an eligible institution or market segment fails.
Leontief utilities	Microeconomics	A fixed-proportions utility model in which bundle value is the minimum of each good’s quantity divided by its required coefficient.
Lerman ratio	Labor EconomicsWelfare Economics	The ratio of the actual increase in income compared to the benefit is the Lerman ratio, which is ordinarily between zero and one.
Lerner index	Industrial Organization	Collapse a firm's market power into one dimensionless number, the markup of price over marginal cost as a fraction of price, L = (P − MC) / P, which under profit maximization also equals the reciprocal of the demand elasticity the firm faces.
Lerner symmetry theorem	International Economics	The trade-theory result that an ad valorem import tariff has equivalent real effects to an equal export tax under specified general-equilibrium assumptions.
Linkage principle	Auction TheoryMechanism Design	The linkage principle is seen in the art market with the tradition of auctioneers hiring art experts to examine each lot and pre-commit to provide a truthful estimate of its value.
Liquidity Preference	Monetary Economics	Keynes's claim that agents hold money out of three motives — transactions, precaution, and speculation — so the interest rate is the reward for parting with liquidity, set in the money market where the rate adjusts until money demanded across the three motives equals the supply the central bank controls.
Liquidity Trap	Monetary Economics	The regime where the central bank's short-rate lever stops working because the rate has hit its effective lower bound and cash and short bonds become perfect substitutes, so added base money is hoarded rather than spent and the transmission to demand is severed even as the lever still moves.
Lorenz Curve	Inequality Measurement	Read a whole distribution's inequality off a single curve by plotting the cumulative share of a quantity against the cumulative share of its ranked holders, so the sag below the perfect-equality diagonal shows how concentrated it is and whether two distributions can be safely ranked.
Lottery (decision theory)	Decision TheoryExpected Utility Theory	A discrete probability distribution over mutually exclusive outcomes or states, treated as an object of preference and choice under risk and often evaluated by probability-weighted utility in expected-utility theory.
Lucas Critique	Macroeconomic Methodology	Refuse to trust a macroeconometric model's historical coefficients for policy evaluation unless they are deep, regime-invariant parameters, because reduced-form relationships are themselves functions of the policy regime and shift the instant policy shifts.
Malthusian Trap	Long Run Growth	The demographic-economic dynamic in which productivity gains trigger population growth fast enough to absorb them, pinning long-run living standards near a subsistence floor through a negative feedback loop — until either technology outruns demographic absorption or the feedback's sign reverses.
Marginal demand	Demand TheoryMicroeconomics	Marginal demand in economics is the change in demand for a product or service in response to a specific change in its price.
Marginal Profit	MicroeconomicsMarginal Analysis	The change in profit generated by a small or one-unit increase in output, equal under differentiable conditions to marginal revenue minus marginal cost and used to locate an interior profit maximum.
Marginal revenue productivity theory of wages	Labor EconomicsWage Determination	A labor-demand theory in which a profit-maximizing firm hires workers until the wage equals labor's marginal product multiplied by the marginal revenue from additional output.
Mark-to-Market Cliff	Accounting and Valuation	The discontinuous worsening of a financial position when a continuously-marked value crosses a contractual threshold, waking a dormant clause whose enforcement — forced selling, collateral calls, cross-default — pushes the reference further in the direction that tripped it.
Market	Market Institutions	A market is an institutional arrangement in which potential counterparties discover, negotiate, or accept terms for exchanging specified goods, services, claims, labor, or other valued objects under rules governing participation, information, price formation, transfer, and enforcement.
Market basket	Price MeasurementPrice Indices	A documented weighted bundle of goods and services priced across times or places to measure inflation, purchasing power, affordability, or cost change.
Market concentration	Industrial Organization and Competition Policy	The degree to which sales, capacity, assets, employment, or another market activity measure is distributed among relatively few firms within a defined relevant market.
Market distortion	Microeconomics	A departure from a declared competitive benchmark that changes prices, quantities or incentives so decentralized choices no longer produce the benchmark allocation.
Market facilitation index	Technical AnalysisTrading Indicators	The Market Facilitation Index (MFI) is the creation of Bill Williams.
Market form	Market StructureIndustrial Organization	Based on the factors that decide the structure of the market, the main forms of market structure are as follows.
Market power	Industrial Organization	Gauge an actor's ability to profitably set price above (or wages below) the competitive level by reading the slope of the downward-sloping residual demand curve it faces, quantified as the price-cost wedge (P − MC)/P.
Market Relation	Industrial Organization	A market relation is a structured economic relation among firms, buyers, sellers, intermediaries, gatekeepers, or market positions in which the parties' roles, exchanged resources, access, competition, dependence, or strategic interconnection shape feasible conduct and outcomes.
Market share	Industrial OrganizationCompetition Policy	A supplier's or product's measured portion of a defined competitive market on a specified, compatible basis.
Marriage penalty	Tax Policy and Public Finance	A tax-system effect in which a married couple owes more tax or receives fewer benefits jointly than the same two people would under a specified unmarried filing counterfactual.
Marshallian Demand Function	Microeconomic Consumer Theory	The unique utility-maximizing consumption bundle selected at each price-and-income combination without utility-preserving compensation.
Max-dominated strategy	Game Theory	A game-theoretic strategy that is never a best response to any admissible strategy profile of the other players, even though no single alternative need yield a strictly higher payoff against every profile.
Mean Log Deviation	Inequality MeasurementEconometrics	In statistics and econometrics, the mean log deviation (MLD) is a measure of income inequality.
Median Voter Theorem	Public Choice	Under majority rule with single-peaked preferences on one policy dimension, binary competition converges to the median voter's ideal point, because that position is the unique Condorcet winner — any platform away from it is beaten by one moving closer.
Merton's portfolio problem	Continuous Time FinancePortfolio Theory	Merton's portfolio problem is a problem in continuous-time finance and in particular intertemporal portfolio choice.
Metallism	Monetary Theory	Metallism is the economic principle that the value of money derives from the purchasing power of the commodity upon which it is based.
Middle-Income Trap	Development Economics	The growth deceleration where a country that rose from low to middle income via factor accumulation stalls before high income, because the engines of the first regime exhaust while the qualitatively different capabilities of an innovation-led regime are not yet built.
Minimal-entropy martingale measure	Mathematical Finance	An equivalent martingale measure selected from an incomplete market by minimizing relative entropy with respect to the objective probability measure.
Minsky Moment	Financial Instability	The financial collapse in which an extended calm endogenously breeds its own undoing — leveraged actors drift from hedge to speculative to Ponzi finance until a modest trigger reveals the hidden fragility and forces a cascade of fire-sale deleveraging; stability is destabilizing.
MIRAB	Development EconomicsSmall Island Economies	A model of small-island political economy organized around migration, remittances, external aid and a large public bureaucracy that distributes and stabilizes those flows.
Misery index (economics)	Macroeconomics	The economic misery index is a composite indicator conventionally formed from inflation and unemployment rates to summarize two household-facing sources of macroeconomic distress.
Mode of Production	Marxian Political Economy	A historically scoped material-production arrangement classified by how productive labor and means are coupled to social relations of production and control.
Modigliani–Miller theorem	Corporate Finance	Establish that in a frictionless capital market a firm's total value is independent of its debt-equity mix — enforced by investors replicating corporate leverage on personal account — so every real financing decision reads as that baseline minus a catalog of named frictions.
Monetarist Paradox	Monetary Economics	A monetary-policy time-horizon reversal: easier money may depress nominal rates initially but raise them later through inflation and expectations, while sustained restraint can produce lower long-run nominal rates.
Monetary Policy	Monetary EconomicsCentral Banking	Monetary policy is the framework and sequence of decisions by a monetary authority that uses interest rates, balance-sheet operations, reserve or liquidity tools, communication, and institutional rules to influence monetary and financial conditions in pursuit of price, employment, exchange-rate, or stability objectives.
Money flow index	Technical Analysis	A bounded price-volume oscillator comparing positive with total signed money flow over a chosen lookback period.
Money Multiplier	Monetary Economics	The relation by which one unit of base money supports up to 1/r units of bank deposits through the chained redeposit of fractional-reserve lending — a causal lever where the reserve fraction binds, but only an ex-post accounting ratio where the central bank accommodates reserve demand.
Monopolistic Competition	Industrial Organization	A market structure where many small firms each sell a differentiated product — giving each a downward-sloping demand curve and local pricing power — while free entry erodes any profit until price equals average cost, leaving excess capacity as the standing signature.
Monopsony power	Labor Economics	Gauge a buyer's ability to set the price it pays below the competitive level by the slope of the upward-sloping residual supply curve it faces (finite elasticity ε), which yields a markdown of roughly 1/ε and the double distortion of underpayment plus under-hiring.
Monotone preferences	Microeconomics	Preferences under which having weakly more of every good and strictly more of a qualifying good is never worse or is strictly better.
Multidimensional Poverty Index	Development EconomicsMultidimensional Poverty Measurement	A dual-cutoff poverty measure that identifies each person or household by a weighted count of simultaneous deprivations, then aggregates the poor population's incidence and average deprivation intensity as MPI = H × A.
Multimarket contact	Industrial Organization	A competitive overlap in which the same firms meet in multiple markets, creating opportunities for cross-market retaliation and possible mutual forbearance.
Multiple principal problem	Common Agency and Multiple Accountability	Analyze delegation when one agent answers to several principals whose preferences, contracts, monitoring, or accountability demands interact and can conflict, duplicate, or free-ride.
Multiplier Effect	Macroeconomics and Aggregate Demand	Read the total output change from a one-shot spending injection off a single number — the leakage rate — by recognizing the successive re-spending rounds as a convergent geometric series summing to 1/(1−c) times the injection.
Multiplier Uncertainty	Macroeconomic Policy	Represent uncertainty about how strongly a policy instrument changes its target, making optimal intervention depend on the distribution and covariance of the transmission coefficient rather than only its estimated mean.
Myerson-regular distribution	Auction TheoryMechanism Design	A regular distribution in auction theory is a value distribution whose virtual valuation is nondecreasing, equivalently whose quantile-space revenue curve is concave under the standard continuous formulation.
Nash welfare rule	Social Choice TheoryWelfare EconomicsFair Division	The Nash welfare rule is often described as a compromise between the utilitarian rule, which maximizes the sum of utilities and emphasizes aggregate efficiency, and the egalitarian rule, which maximizes the minimum utility and emphasizes the worst-off individual.
National Intangible Capital	Intellectual Capital MeasurementNational Intangibles	A country-level intellectual-capital accounting construct that aggregates indicators of human, market, process, and renewal capacities and relates the resulting stock estimate to modeled GDP impact and input–output efficiency.
Natural Rate of Unemployment	Macroeconomics and Labour	The unemployment rate consistent with stable inflation in the long run — the frictional-plus-structural floor set by labour-market frictions and institutions, below which demand stimulus buys only accelerating inflation, never durable jobs.
Net (economics)	Economics Accounting and Finance	A value remaining after specified additions and deductions are applied to a corresponding gross amount, with the modifier meaningful only when the adjustment boundary is named.
Net domestic product	National Accounting	Gross domestic product minus consumption of fixed capital, estimating domestic production net of the capital used up during the accounting period.
Net Foreign Assets	International MacroeconomicsBalance of Payments	The net foreign asset (NFA) position of a country is the value of its net claims on the rest of the world (RoW), i. e. the value of the assets that country owns abroad, minus the value of the domestic assets owned by foreigners.
Net material product	National Accounting History	A former socialist-accounting aggregate of material-sector net output, excluding fixed-capital consumption and most nonmaterial services.
New trade theory	International EconomicsTrade Models	A family of international-trade models explaining intra-industry trade and specialization through increasing returns, product differentiation, imperfect competition and market size.
No-reserve auction	Auction Market DesignAuction Theory	An auction without a seller reserve threshold, in which the highest valid bid is not refused solely for its price.
Non-convexity (economics)	Nonconvex Economies	An economic setting in which preferences, technologies or feasible sets violate convexity, allowing indivisibilities, increasing returns and multiple or unsupported competitive outcomes.
Non-renewable resource	Natural Resource EconomicsExhaustible Resource Classification	Classify a natural-resource stock as non-renewable when replenishment on the relevant human decision horizon is negligible relative to extraction or consumption, making depletion and stock accounting constitutive.
North–South model	Development Economics	Findlay's stylized two-region growth model linking a manufacturing North and primary-exporting South through trade and terms-of-trade feedback.
Old-age-security hypothesis	Demographic EconomicsFertility Theories	A demographic-economic hypothesis that parents demand more children where adult offspring are expected to provide income, care and protection in old age, with pensions reducing that motive.
Oligopoly	Industrial Organization	A market structure of a few sellers each large enough that its choices visibly move the others, so optimal strategy turns on anticipating rivals' responses — with the outcome swinging between competitive and monopoly-leaning by which equilibrium template (Cournot, Bertrand, Stackelberg, or repeated-game collusion) the market fits.
One-shot deviation principle	Dynamic Game Theory	A sequential-game criterion stating that a strategy profile is subgame-perfect when no player can gain by changing one action at one information point and then returning to the prescribed strategy.
Open-source economics	Peer ProductionCommons Based Production	Open-source economics is an economic platform based on open collaboration for the production of software, services, or other products.
Operating Surplus	National AccountsMacroeconomicsOfficial Statistics	The national-accounts balance of production income left after labor compensation and production taxes less subsidies, before property income.
Optimum sustainable yield	Fisheries EconomicsBioeconomicsNatural Resource Economics	In population ecology and economics, optimum sustainable yield is the level of effort (LOE) that maximizes the difference between total revenue and total cost.
Option Value (Cost–Benefit Analysis)	Welfare EconomicsEnvironmental EconomicsCost Benefit Analysis	Willingness to pay to preserve a public asset or service as a future-use opportunity under uncertainty, especially when loss is irreversible, replacement costly, and the service non-storable.
Overconfidence effect	Judgment and Decision Making	Miscalibration in which confidence, perceived performance, comparative rank, or precision systematically exceeds warranted accuracy.
Panjer recursion	Actuarial Mathematics	A recursive algorithm for computing an aggregate-loss distribution when claim counts belong to the Panjer (a,b,0) class and severities are discrete or discretized.
Parabolic SAR	Financial Technical Analysis	A recursive technical-analysis indicator that places a trailing stop-and-reverse level behind a price trend and accelerates it toward the trend’s extreme point.
Paradox of Plenty (Resource Curse)	Development Economics	The resource-curse regularity that extractive-rent dependence can turn abundance into slower development through five reinforcing channels — Dutch disease, revenue volatility, severed tax accountability, conflict finance, and diversification crowd-out — whose mix and timing are gated by prior institutional quality.
Paradox of Thrift	Macroeconomics	The macroeconomic result that a simultaneous, economy-wide rise in the desire to save lowers total saving in equilibrium, because the coordinated withdrawal of spending contracts demand and income until realized saving falls.
Paradox of toil	MacroeconomicsLiquidity Trap Paradoxes	A zero-lower-bound macroeconomic result in which a collective increase in willingness to work lowers wages and expected inflation enough to raise real interest rates, reduce demand and decrease equilibrium employment.
Pareto index	Econometrics	The shape parameter of a Pareto income or wealth distribution, often interpreted as a tail-inequality or concentration exponent.
Partial Equilibrium	Microeconomics	The Marshallian method of isolating one market and solving its equilibrium price and quantity off supply and demand while holding the rest of the economy as fixed background — trading economy-wide feedbacks for tractability, valid only when the studied market is small and weakly connected.
Partially observable Markov decision process	Decision TheoryPlanning Under Uncertainty	A sequential decision model with Markovian hidden states, stochastic observations and actions chosen from observation histories or belief-state probability distributions.
Participation constraint (mechanism design)	Mechanism DesignContract Theory	An individual-rationality condition requiring each relevant participant's utility from joining a mechanism to be at least the utility of the outside option, evaluated ex ante, interim, or ex post according to available type information.
Payment for Order Flow	Securities Market StructureMarket MicrostructureBrokerage	Compensation paid by a market maker or trading venue to a broker for routing customer orders to that counterparty, creating a revenue stream whose execution-quality and conflict implications require disclosure and oversight.
Peace war game	Game TheoryIterated Games	Peace war game is an iterated game originally played in academic groups and by computer simulation for years to study possible strategies of cooperation and aggression.
Pecuniary Externality	Welfare EconomicsGeneral Equilibrium	A welfare effect on other agents transmitted through an action-induced change in market prices rather than through a direct change in their production possibilities, consumption technology, or physical resources.
Peer-to-peer investing	Financial MarketsMarketplace Lending	Investment in borrower notes originated through an online peer-to-peer lending platform, exposing investors to credit, liquidity, servicing, platform and regulatory risks without a traditional bank intermediary.
Perfect Competition	Microeconomic Theory	The idealized market of many small price-takers trading a homogeneous good under free entry and full information, yielding price equal to marginal cost and a Pareto-efficient allocation — a benchmark whose five assumptions, when they break, name every standard market failure.
Perfect Information	Extensive Form Games	In an extensive-form game, every decision maker can identify the exact history at each turn, so every decision information set is a singleton.
Peso problem	Asset Pricing and Inference	Explain an apparent pricing anomaly — persistent forward-rate bias or too-good Sharpe ratios — as a sampling artifact, in which the price correctly embeds a rare severe tail event that the finite observation window happened to omit.
Phillips Curve	Macroeconomics	The short-run inverse relation between unemployment and inflation — positioned by expected inflation, sloped by how anchored those expectations are, vertical at the natural rate in the long run, and displaced by supply shocks — whose exploitable trade-off dissolves once agents come to expect the inflation.
Pignistic probability	Decision TheoryTransferable Belief Model	A decision probability obtained from a belief function by distributing each focal set's mass equally among its members when a single probabilistic choice is required.
Pigou–Dalton principle	Welfare EconomicsInequality Measurement	The Pigou-Dalton transfer principle says that a rank-preserving transfer from a richer person to a poorer person must reduce measured inequality, provided their order is not reversed.
Pirate game	Game Theory and Mechanism Design	A toy sequential-bargaining model showing how backward induction in a propose-vote-or-eliminate mechanism lets the most senior proposer capture nearly the whole prize, because each voter's price is their continuation payoff and downstream subgames impoverish enough players to buy a cheap minimum coalition.
Planned obsolescence	Industrial Economics and Product DesignDurability and Replacement Strategy	A product strategy that intentionally limits useful life, durability, compatibility, or perceived fashionability to accelerate replacement demand.
Platform economy	Digital Platform Economics	China's platform economy is dominated by homegrown companies like Alibaba and Tencent, while foreign platforms like eBay have struggled to gain market share.
Pollution haven hypothesis	Environmental EconomicsInternational Trade	The contested claim that weaker environmental regulation can attract pollution-intensive production or investment through lower compliance costs.
Polytomous choice	Econometrics	A discrete-choice setting in which a decision maker selects among more than two mutually distinguished alternatives.
Pooling Equilibrium	Game Theory	Sustain a signaling-game equilibrium in which every hidden sender type chooses the same on-path action and the receiver's posterior remains its prior.
Porter Hypothesis	Environmental EconomicsInduced Innovation	The hypothesis that well-designed, sufficiently stringent environmental regulation can stimulate innovation and efficiency, with a strong version proposing that resulting gains may offset compliance costs and improve competitiveness.
Portfolio (finance)	Portfolio TheoryInvestment Management	In finance, a portfolio is a collection of investments.
Portfolio Optimization	Portfolio Theory	Choose a feasible combination of investments or projects by optimizing a declared portfolio-level criterion.
Positional good	Welfare EconomicsConsumption Theory	Positional goods are goods valued only by how they are distributed among the population, not by how many of them there are available in total (as would be the case with other consumer goods).
Poverty gap index	Development EconomicsPoverty Measurement	The poverty gap index is a measure of the degree of poverty in a country.
Poverty Trap	Development Economics	A self-reinforcing development dynamic in which those below a critical resource threshold cannot accumulate enough to escape a low-level equilibrium — a bistable attractor where sub-threshold inputs are absorbed and reverted, while a large sustained push flips the basin and persists on its own.
Price Level	Monetary Economics	A normalized aggregate of prices for a defined economic domain and period whose ratios track the common monetary-price component used to measure inflation, purchasing-power change, and real-versus-nominal magnitudes.
Price Puzzle	Monetary EconometricsMonetary Economics	A monetary-policy VAR anomaly in which an identified contractionary shock is followed by an estimated price rise.
Price-to-Book Ratio	Equity Valuation	The price-to-book ratio compares a company's market capitalization or share price with its accounting book value.
Principle of effective demand	MacroeconomicsKeynesian Theory of Output and Employment	In Keynesian macroeconomic theory, determine output and employment where entrepreneurs' aggregate proceeds expectations meet the aggregate supply price, allowing the resulting demand-constrained position to occur below full employment.
Prisoner's dilemma	Game Theory	In game theory, the prisoner's dilemma is a thought experiment involving two rational agents, each of whom can either cooperate for mutual benefit or betray their partner ("defect") for individual gain.
Privacy Paradox	Digital Behavior	Explain the stable gap between people's high stated concern for privacy and their routine sharing of personal data for trivial benefits as a decoupling of attitude from choice behavior, produced by present bias, decision fatigue, opacity, and friction asymmetry.
Private-sector involvement in sovereign debt resolution	Sovereign Debt Restructuring	A sovereign crisis arrangement in which private creditors' repayment claims or rollover commitments are changed to address the sovereign's financing problem.
Privileged group	Public Economics	A collective-action group containing at least one member whose private benefit from a public good exceeds the full cost of supplying it.
PRIX index	Energy EconomicsPolitical Risk Analysis	The PRIX index (or Political Risk for Oil Exports Index) is a financial indicator for international oil markets to understand the political risks associated with oil exports.
Producer Price Index	Price Statistics	A periodically compiled price index estimating average change over time in transaction prices received by domestic producers for a defined, weighted set of outputs at specified stages of production.
Producer Surplus	Microeconomics Welfare Analysis	The gap between the price a seller receives and its reservation price (marginal cost), aggregated as the area between the market price line and the supply curve — the seller's side of a conserved welfare ledger that any market distortion redistributes or destroys.
Production (economics)	Production Economics	The organized transformation of material and immaterial inputs into goods or services, represented by feasible production sets, technologies, costs, and output relations.
Productive capacity	—	The maximum sustainable output an economy, organization, asset or resource base can produce with its available capabilities and linkages.
Productive Efficiency	Production Theory	The condition of producing a chosen output at the lowest feasible input cost — operating on the production frontier — with any interior point measuring recoverable waste as its distance inside, held strictly apart from the allocative question of whether the right mix is produced.
Productivity Paradox	Technology and Growth	The observation that economy-wide investment in a new general-purpose technology fails to show up in aggregate productivity statistics for years or decades, because measured gains lag the complementary intangible investment — process redesign, skills, restructuring — the technology's payoff actually depends on.
Promoting adversaries	Strategic Interaction	A mutually reinforcing rivalry in which opposing organizations gain attention, legitimacy or resources by attacking one another while avoiding decisive defeat.
Public Choice	Political Economy	The research program applying economics' rational-self-interest assumptions to politics — modelling voters, politicians, and bureaucrats as utility-maximizers responding to institutional incentives, so government failures read as predicted equilibrium and reform runs through the rules, not the roster.
Public Debt	Public Finance	The dated stock of debt-instrument liabilities owed by a defined government sector, measured under explicit perimeter, consolidation, valuation, currency, maturity, and gross-or-net conventions.
Public Goods Game	Experimental EconomicsPublic Economics	Model voluntary contributions to a shared account whose private and group returns pull in different directions.
Purchasing Managers' Index	Business Tendency Surveys	A Purchasing Managers' Index converts recurring business-panel reports of improvement, no change, or deterioration into diffusion indices centered at 50, often combining selected components into a timely headline indicator.
Purchasing power parity	International Economics	Purchasing power parity (PPP) is a measure of the price of specific goods in different countries and is used to compare the absolute purchasing power of the countries' currencies.
Put/Call Ratio	Technical AnalysisDerivatives Markets	In finance the put/call ratio (or put-call ratio, PCR) is a technical indicator demonstrating investor sentiment.
Quality bias	Price StatisticsIndex Number Theory	Quality bias in price indices is a kind of mismeasurement if they do not incorporate data on the quality of goods from period to period, as well as their nominal price.
Quantitative easing	Monetary EconomicsUnconventional Monetary Policy	A central-bank balance-sheet policy that purchases longer-duration or riskier financial assets at announced scale when ordinary short-rate policy is constrained, seeking to ease broader financial conditions through yields, portfolios, liquidity and expectations.
Quantity Theory of Money	Monetary Economics	Bind money supply, velocity, the price level, and real output in the identity MV = PY, then add the behavioural premises that velocity is stable and output is set by real factors — so that in the long run changes in the money stock translate proportionally into the price level.
Rachev ratio	Quantitative Finance	A financial performance ratio comparing expected extreme positive returns with expected extreme losses at specified tail probabilities.
Radon–Nikodym set	Fair Division	The convex range of a vector measure formed from several agents' nonatomic valuations of measurable cake pieces, representing all simultaneously attainable value vectors.
Ragnar Nurkse's balanced growth theory	Development Economics	A development theory advocating coordinated simultaneous investment across complementary sectors to enlarge markets and escape low-income demand constraints.
Random walk hypothesis	Financial Economics	The financial-market hypothesis that successive asset-price changes are sufficiently independent or unpredictable that past price movements alone cannot systematically forecast future changes.
Rank aggregation	Social Choice Theory	The construction of one consensus ordering from multiple rankings over a common set of alternatives.
Rational Choice Model	Choice Theory	Model an actor's choice as the maximal feasible option under an attributed evaluation, to explain or predict behavior.
Rational Inattention	Information EconomicsMacroeconomics	Economic choice with optimally selected partial information under an attention cost or capacity limit.
Real net output ratio	Managerial Economics	The share of a firm’s total production value created internally rather than purchased as externally produced goods and services.
Real vs. Nominal Value Distinction	Monetary Macroeconomics	The operation of separating a monetary quantity's real change from the drift in its unit's purchasing power by dividing a nominal series through a price index and rebasing — treating the measuring unit itself as a variable, so cross-time comparisons are not confounded by inflation.
Redistribution	Public Economics	The deliberate reallocation of income, wealth, or consumption between groups through state authority — a clearing-house collecting from a source base and paying a recipient base under rules set so the net flow runs from those with more to those with less along a named axis.
Reilly's law of retail gravitation	Retail GeographySpatial Interaction Models	A gravity-model law predicting retail catchment breakpoints from center size and distance.
Relational goods	Social EconomicsCivil Economy	Relational goods are non-material goods that can only be produced and consumed within groups, and which are intrinsically linked to relationships and interaction.
Relative Strength Index	Technical Analysis	The relative strength index (RSI) is a technical indicator used in the analysis of financial markets.
Rent-Seeking Trap	Public Choice	The public-choice pathology in which institutional rules make the marginal return on capturing an existing rent exceed the return on producing new value, so effort is dissipated into contests over distribution — self-reinforcing where the rent-defending coalitions persist and manufacture further rents.
Rent-to-own	Consumer Finance	While rent-to-own terminology is most commonly associated with consumer goods transactions, the term is sometimes used in connection with real estate transactions.
Reprivatization	Political EconomyPost Nationalization Property TransitionTransition Economics	The transfer of property or an enterprise from state control back to private status after nationalization or seizure, through restitution to former owners, compensation, or sale to new private owners under a defined legal process.
Repugnant Market	Market Design	A repugnant market is an area of commerce that is considered by society to be outside the range of market transactions and that bringing this area into the realm of a market would be inherently immoral or uncaring.
Return on invested capital	Corporate Finance	A company-level ratio of after-tax operating profit to average invested capital, used to assess operating return on deployed capital.
Return on tangible equity	Banking and Financial Analysis	A profitability ratio comparing common-shareholder earnings with average tangible common equity under a disclosed calculation convention.
Revelation Principle	Mechanism Design Game Theory	The mechanism-design theorem that any outcome achievable by any mechanism is also achievable by a direct mechanism where agents truthfully report their private type — collapsing the search over all mechanisms to a tractable optimization over incentive-compatibility constraints, while saying nothing about which mechanism to deploy.
Revenue Equivalence Theorem	Auction Theory	The auction-theory result that under symmetric independent-private-values conditions, every format allocating to the highest bidder yields the seller the same expected revenue — pinning revenue to the allocation rule and lowest-type rent, so format matters only where a condition fails and the failure direction names the preferred format.
Ricardian Equivalence	Macroeconomics	Treat a debt-financed tax cut as a deferred tax of equal present value, so forward-looking households save the windfall to meet the future bill and the financing choice adds no stimulus.
Risk of ruin	Actuarial and Financial Probability	The probability that accumulated losses drive capital or a bankroll below a specified absorbing or operational threshold before a declared horizon or target is reached.
Risk return ratio	Performance Measurement	A performance measure relating an investment's return over a stated period to a stated risk quantity, such as maximum drawdown, so reward is interpreted relative to exposure.
Risk-Free Rate Puzzle	Asset Pricing Macrofinance	The asset-pricing anomaly that a CRRA model calibrated to the observed equity premium predicts a real risk-free rate far above the ~1% seen — because the single parameter γ is overloaded as both risk aversion and the inverse elasticity of intertemporal substitution, so fitting one target misfits the other.
Rosenfeld's law	Energy EconomicsEnergy Intensity	Rosenfeld's law is an axiom relating physics to economics, that states that the amount of energy required to produce one dollar of GDP has decreased by about one percent per year since 1845.
Roy's identity	MicroeconomicsConsumer Theory	Roy's identity (named after French economist René Roy) is a major result in microeconomics having applications in consumer choice and the theory of the firm.
Rubinstein bargaining model	Game TheoryBargaining Theory	An infinite-horizon alternating-offers bargaining game whose unique subgame-perfect division reflects the players' discounting and first-mover position.
Ruin theory	Actuarial ScienceInsurance Risk Processes	An actuarial-probability framework modeling an insurer's surplus under premium inflow and random claims to quantify the probability and timing of insolvency.
Rule of 72	Financial Mathematics and Exponential Growth	A mental approximation for exponential doubling time obtained by dividing 72 by the percentage growth rate per compounding period.
Sales cannibalization	Marketing	Sales gained by one offering or outlet that displace sales of another unit in the same commercial system.
Samaritan's dilemma	Public ChoiceWelfare EconomicsGame Theory	The Samaritan's dilemma arises when assistance intended to improve a recipient's welfare weakens incentives for self-provision, creating dependence or strategically greater need.
Sargan–Hansen Test	Econometrics and Generalized Method of Moments	An overidentification test for instrumental-variable or GMM models that asks whether surplus instruments are jointly orthogonal to fitted residual moments, conditional on at least one maintained valid identifying set.
Saving (economics)	MacroeconomicsHousehold Economics	In economics, saving is defined as after-tax income minus consumption.
Saving identity	National Income Accounting	The saving identity equates aggregate saving sources with physical investment in national-income accounting.
Say's Law (Supply Creates Its Own Demand)	Macroeconomics	The classical claim that aggregate production generates the income constituting aggregate demand, so a general glut cannot persist — a conditional resting on flexible market-clearing prices, no permanent hoarding, and a loanable-funds market that routes saving into investment.
Scarcity Development Cycle	Resource EconomicsEnvironmental Economics	A proposed resource-economy feedback cycle in which expanding use depletes accessible supply, rising scarcity and prices stimulate innovation, substitution, reuse, or recycling, and the resulting supply response temporarily relaxes scarcity.
Scarcity value	Price TheorySupply and Demand	Scarcity value is an economic factor describing the increase in an item's relative price by a low supply.
Scitovsky Paradox	Welfare EconomicsCompensation Criteria	A potential-compensation reversal that can rank both a policy change and its undoing as welfare improvements.
Search Good	Information EconomicsConsumer Economics	A search good is a product or service whose relevant attributes consumers can inspect and evaluate with reasonable accuracy before purchase or consumption.
Second-Lien Loan	Leveraged FinanceSecured Corporate Lending	A secured credit facility whose lien on shared collateral is contractually junior to a first-lien facility, routing control and collateral proceeds to the first-lien creditors before the second-lien creditors while preserving a residual secured claim.
Secular Stagnation	Macroeconomic Dynamics	A structural glut of saving over investment pushes the market-clearing interest rate below zero and beneath the lowest real rate a central bank can reach from its nominal floor, so rate cuts run out of room and the shortfall persists as deficient demand rather than the trend.
Shadow of the law	Law and Economics	The influence expected court outcomes and legal procedures exert on private bargaining, settlement, and plea decisions outside trial.
Shapley value	Cooperative Game TheoryPayoff Allocation	The unique cooperative-game allocation that assigns each player their average marginal contribution over all coalition-entry orders under efficiency, symmetry, dummy and additivity axioms.
Shapley–Shubik power index	Cooperative Game Theory	A voter’s a priori power measured as the probability of being pivotal over all orderings in a monotone simple voting game.
Shareholder yield	Corporate FinanceEquity Valuation	Shareholder yield is the total rate at which a company returns value to shareholders through cash dividends, net share repurchases, and net debt reduction.
Shephard's Lemma	Microeconomic DualityConsumer TheoryProduction Theory	The duality result that differentiating a regular expenditure or cost value function with respect to a price recovers the associated Hicksian good demand or conditional factor demand.
Shrinkflation	InflationConsumer Prices	A disguised increase in unit price produced when a seller reduces a packaged product's size or quantity while leaving its displayed package price unchanged or nearly unchanged.
Siegel's paradox	International Finance Theory	The apparent expected-value inconsistency that reciprocal future exchange rates cannot both have expected appreciation, exposing numeraire and expectation dependence under uncertainty.
Signalling (economics)	Information Economics	The strategic use of observable actions or attributes to convey credible information about otherwise hidden qualities in a market or game.
Simple commodity production	Marxian Economics	A mode of commodity exchange in which independent producers own their means of production and sell their own products to obtain other use values.
Simultaneous action selection	Game MechanicsDecision Phases	A game decision procedure in which players fix current actions without seeing one another's choices, disclose them together, and resolve their combination under game rules.
Single-crossing condition	Monotone Comparative Statics	An ordered-comparison property under which the difference between two functions changes sign at most once and in a fixed direction.
Slutsky Decomposition	Microeconomic Consumer Theory	Decompose a price-induced change in consumer demand into a compensated substitution effect from changed relative prices and an income effect from changed real purchasing power, so the two terms sum exactly to the observed response.
Snob Effect	Consumer Demand Anomalies	The demand pattern in which a consumer segment values a good more when fewer others own it — a negative prevalence term in utility that decomposes the good into a fixed use-value and a prevalence-dependent rarity signal.
Social accounting matrix	National AccountingComputable General Equilibrium	A square matrix recording transactions and income flows among production, factors, institutions, and accounts.
Social Surplus	Welfare Economics	Measure a market's total net benefit as the area between the demand and supply curves — consumer plus producer surplus — so a policy's efficiency cost reads off the deadweight-loss triangle of trades the price wedge suppresses, distinct from surplus merely transferred.
Solow Computer Paradox	Productivity and Growth	The puzzle that heavy IT investment coincided with a productivity slowdown, not an acceleration — resolved as a deployment-to-impact lag: the headline measure waits on the complementary intangible stocks (process redesign, retraining, standards) a general-purpose technology must accumulate first.
Solow–Swan Model	Growth Theory	The neoclassical growth model whose diminishing-returns structure drives each economy to a parameter-pinned steady state, yielding conditional convergence — economies sharing fundamentals close their gaps at a rate set by the capital share, while saving raises the level of income but not the long-run growth rate.
Spot Market	Market Structure and Settlement	Organize trades in financial instruments or commodities for delivery and settlement on the market's current, near-term convention, as distinct from contracting now for deferred delivery.
St. Petersburg Paradox	Decision Theory Expected Utility	A gamble whose expected monetary value is infinite yet which real deciders will pay only a few coins to enter, exposing that a value function linear in money mishandles fat-tailed payoffs and must be replaced by a concave or bounded utility.
Stable matching problem	Matching Theory	The problem of pairing members of two preference-bearing sets so that no unmatched pair would both prefer each other to their assigned partners.
Stag Hunt	Game Theory	Model a cooperation problem in which the joint payoff-dominant choice and a certain safe choice are both equilibria, so the barrier to cooperating is not temptation but coordination under uncertainty about the partner — fixed by assurance, not enforcement.
State capitalism	Political EconomyState Market Systems	An economic organization in which state institutions own, control or strategically direct commercially operated enterprises and capital accumulation while retaining markets, wage labor and enterprise-style management.
State socialism	Political EconomySocialist Ideologies and Institutions	Organize a socialist political economy around state ownership or state administration of major productive assets, treating public authority as the principal institutional vehicle for socialization or transition.
Statistical relative-value trading	Quantitative Trading	Trades modeled relative departures with opposing positions that seek, but do not guarantee, a return on convergence.
Sterling Ratio	Portfolio Performance MeasurementInvestment Management	The Sterling ratio (SR) is a measure of the risk-adjusted return of an investment portfolio.
Stochastic Modelling in Insurance	Actuarial ScienceInsurance Risk Modelling	The joint probabilistic projection of insurance claims, expenses, policy behavior, assets, and economic conditions to obtain distributions of liabilities, solvency, capital, and guarantee outcomes rather than a single best estimate.
Stochastically stable equilibrium	Evolutionary Game Theory	An equilibrium state retaining positive limiting stationary probability as perturbation noise in an evolutionary or learning process vanishes.
Stock market bubble	Financial Markets	A stock-market episode of equity prices persistently outstripping defensible fundamental-value estimates, often sustained by self-reinforcing demand and hard to establish conclusively in real time.
Strategic move	Game Theory	A strategic move in game theory is an action taken by a player outside the defined actions of the game in order to gain a strategic advantage and increase one's payoff.
Strong Nash equilibrium	Game Theory	A strategy profile from which no coalition can jointly deviate so that every coalition member becomes strictly better off.
Structural Break	Econometrics	Locate a time boundary at which one or more parameters of a statistical data-generating relationship change, so observations on the two sides no longer share one invariant regression or time-series regime.
Structural Transformation	Development EconomicsMultisector Growth	A sustained reallocation of an economy's employment, value added, or expenditure across broad sectors—classically away from agriculture, through a manufacturing rise, and toward services—as income, productivity, prices, and demand change.
Subgame Perfect Equilibrium	Game Theory	Refine the Nash equilibria of a sequential game by keeping only strategy profiles that prescribe a best response in every subgame, discarding outcomes propped up by threats a player would never actually carry out.
Subjective theory of value	Economic Thought	The economic theory that goods derive exchange-relevant value from agents’ marginal evaluations rather than inherent substance or embodied labor alone.
Substitution bias	Price Index MeasurementEconomic Statistics	Consider how consumer expenditures are reflected in a consumer price index.
Substitution Effect	Microeconomics	Isolate the part of a consumer's demand response to a price change that comes purely from shifted relative prices, holding real purchasing power constant, by hypothetically compensating income and observing how she reallocates toward the now-cheaper goods.
Sudden Stop (Economics)	International MacroeconomicsCapital Flows	An abrupt, unusually large decline in external capital inflows that forces rapid balance-of-payments and domestic-spending adjustment, often with credit contraction, depreciation, and output loss.
Sunshine Tax	Regional EconomicsSpatial Equilibrium and Amenity Valuation	The informal locational amenity premium paid through some combination of lower amenity-adjusted earnings and higher housing or living costs to reside in a desirable sunny, mild, or otherwise 'paradisal' place—not a government levy and not a raw cost gap whose cause can be assumed.
Supply	Microeconomics	Model producer behavior as a whole price-to-quantity schedule rather than a single quantity, upward-sloping because expanding output raises marginal cost, so any disturbance either moves output along the curve (only the good's own price) or shifts the whole curve (everything else).
Sure-thing principle	Decision Theory	A decision principle requiring the same action when it is preferred both conditional on an event and conditional on its complement.
Sustainable National Income	Environmental EconomicsNational Accounting	A model-based environmental indicator estimating the maximum national production attainable with the technology of a stated year while maintaining specified vital environmental functions indefinitely.
Taleb Distribution	Financial Risk	A negatively skewed payoff profile in which frequent small gains conceal rare, very large losses that dominate long-run value and can be hidden by finite samples and asymmetric incentives.
Tariff	International Trade PolicyCustoms Administration	A customs rule that assesses a duty on specified goods when they enter a customs territory.
Taste-based discrimination	Labor Economics	An economic model in which decision makers accept a material cost to avoid interaction with a disliked group, producing unequal market outcomes unrelated to productivity.
Tax buoyancy	Public FinanceFiscal Analysis	The observed proportional response of tax revenue to growth in GDP or another stated income base, including discretionary policy and administrative effects that tax elasticity removes.
Tax-benefit model	MicrosimulationPublic Finance	One example is EUROMOD, which models taxes and benefits for 27 EU states, and its post-Brexit offshoot, UKMOD.
Taxable income elasticity	Public EconomicsOptimal Taxation	The taxable income elasticity, or the elasticity of taxable income with respect to the net-of-tax rate, is a concept in public economics that measures how reported taxable income responds to changes in marginal tax rates, expressed with respect to the net-of-tax rate (one minus the marginal tax rate).
Taylor rule	Monetary Economics	A monetary-policy reaction rule that sets a nominal short-term interest-rate target as a neutral rate plus responses to inflation's deviation from target and the output gap.
Technical analysis	Market Analysis	A disputed financial-market methodology that seeks trading or forecasting signals from historical price, volume and derived chart patterns rather than primarily from issuer fundamentals.
Tendency of the rate of profit to fall	Marxian Political Economy	A Marxian conditional tendency linking capital composition to profitability, subject to counteracting forces.
The bezzle	Financial Fraud	The still-undiscovered stock of misappropriated entrusted wealth whose owner continues to treat the corresponding claim as intact.
Theil Index	Distributional Analysis	An additively decomposable generalized-entropy inequality measure comparing population shares with shares of a positive resource, with Theil T weighting log relative shares by the resource and Theil L weighting log shortfalls by population.
Theory of Storage	Commodity EconomicsCommodity Futures Pricing	A commodity-pricing theory in which inventories connect spot and deferred prices through financing and physical storage costs net of the marginal convenience yield of holding usable stock.
Theory of the second best	Welfare Economics	A common misinterpretation of the theory, sometimes termed the fallacy of exhaustive effort, is the assumption that when one optimality condition cannot be satisfied, satisfying as many of the remaining conditions as possible must yield the second-best outcome.
Threshold population	Economic GeographyCentral Place Theory	The minimum market population needed to support a particular good or service at a location under assumptions about demand, price, costs and travel behavior.
Throw-Away Paradox	Exchange EquilibriumGeneral Equilibrium Theory	An exchange-equilibrium result in which an agent discards part of an initial endowment before trade and thereby reaches an equilibrium allocation the agent strictly prefers to the no-disposal allocation.
Tight money policy	Monetary Policy	A third monetary policy strategy, targeting the money supply, was widely followed during the 1980s, but has diminished in popularity since then, though it is still the official strategy in a number of emerging economies.
Time-Saving Bias	Judgment and Decision MakingIntuitive Rate Time Estimation	Systematically misjudge time gained or lost from a rate change by treating the rate–time relation as linear or proportional instead of reciprocal, undervaluing changes from low rates and overvaluing equal changes from high rates.
Timing Risk	Innovation and Venture	The failure mode where a technically sound product, technology, or policy fails not from its own defects but because the surrounding environment is not yet — or is no longer — ready to absorb it, treating environmental readiness as a risk factor independent of execution.
Tobin's q	Corporate Finance and Investment	The ratio of a firm's market value to the replacement cost of its physical assets, read against a threshold of one to signal whether capital should flow in (build) or out (divest) — because building beats buying only when the market prices assembled capital above the cost of reproducing it.
Too big to fail	Financial RegulationSystemically Important Institutions	A systemic-risk condition in which authorities are expected to support a large or interconnected institution because its disorderly failure would impose unacceptable economy-wide damage.
Total return index	Financial Index Methodology	A chained financial index level that credits both asset price changes and methodology-eligible income from a specified weighted constituent universe.
Total revenue test	MicroeconomicsPrice Elasticity	A ceteris-paribus diagnostic for local price elasticity of demand that observes whether total revenue P×Q moves with or against a price change: same-direction movement indicates inelastic demand and opposite movement elastic demand.
Trade globalization	Trade IndicatorsInternational Economics	Trade globalization is a type of economic globalization and a measure (economic indicator) of economic integration.
Trading Indicator	Financial MarketsTechnical Analysis	A trading indicator is a rule-defined transformation of time-indexed market data that produces a series, band, oscillator, threshold, or event intended to summarize trend, momentum, volatility, range, volume, or another market feature for trading analysis under specified parameters and decision conventions.
Transformation in economics	Development Economics	A sustained shift in the dominant composition of economic activity, employment, production, institutions, and capabilities across sectors or modes of organization.
Triffin Dilemma	International Monetary System	The structural bind in which a national currency serving as the world's reserve asset must run persistent deficits to supply global liquidity, yet those same deficits erode the confidence that makes the currency worth holding — two roles one issuer cannot jointly satisfy over time.
TRIN (Arms Index)	Market Breadth AnalysisTechnical Analysis	An intraday market-breadth indicator equal to the ratio of advancing to declining issues divided by the ratio of advancing to declining share volume for the same universe and interval.
Triple exponential moving average	Technical Analysis	The Triple Exponential Moving Average (TEMA) is a technical indicator in technical analysis that attempts to remove the inherent lag associated with moving averages by placing more weight on recent values.
Tullock Paradox	Public Choice and Rent Seeking	The puzzle that observed rent-seeking expenditures — lobbying fees, contributions, access payments — run far below the value of the rents they secure, read as a diagnostic signal that barriers to entry keep competition from dissipating the prize as the standard model predicts.
Two-Moment Decision Model	Decision TheoryDecisions Under Risk	A decision model that ranks uncertain alternatives using two moments, usually mean and variance, of their outcome distributions.
Törnqvist index	Index NumbersPrice Statistics	In economics, the Törnqvist index is a price or quantity index.
Ulcer Index	Investment Risk Metrics	The Ulcer Index is the root mean square of percentage drawdowns below a running high, measuring how deep and persistent a past investment path stayed underwater.
Ultimatum Game	Behavioural Game Theory	A two-player, one-shot bargaining test in which a proposer splits a fixed stake and a responder may accept or reject for nothing, isolating costly punishment of unfairness by pitting the selfish equilibrium against the offers and rejections people actually make.
Underwriting Contract	Securities UnderwritingInvestment Banking	A securities-offering agreement that allocates duties and sale risk between an issuer and one or more underwriters, specifying the offering, price, conditions, representations, indemnities, and firm-commitment, best-efforts, all-or-none, or standby obligation.
Unit of account	Monetary Economics	In economics, unit of account, sometimes called currency unit or monetary unit, is a standard unit of measurement of the market value of goods, services, and other transactions.
Unit-Economics Mirage	Venture Business Models	The error of judging a business viable from a rising aggregate metric — revenue, users, gross merchandise volume — while its fully-loaded per-unit economics are structurally negative, exposed by testing the contribution on the next unit rather than the average across existing ones.
Value at risk	Financial Risk Management	Value at risk (VaR) is a measure of the risk of loss of investment/capital.
Vanishing hand	Industrial OrganizationBusiness History	An industry-evolution hypothesis in which early managerial integration yields to more specialized market coordination as standards, capabilities, and exchange institutions mature.
Variable Cost	Cost TheoryProduction Economics	The portion of total cost that changes with a declared activity or output level over a stated time horizon and relevant operating range, whether proportionally, stepwise, or nonlinearly.
Variance Gamma Process	—	A pure-jump Lévy process formed by evaluating Brownian motion with drift at an independent gamma random clock, producing stationary independent increments with tunable skewness and heavy tails.
Veblen Effect	Consumer Theory Status Goods	The anomaly that, for status goods, demand rises with price rather than falling — because the conspicuous high price is itself the costly signal of the buyer's wealth, so cutting it destroys the signal and drives out the very buyers who constitute the market.
Velocity of money	Monetary Economics	The average number of times a unit of money changes hands in a period, computed as nominal spending over the money stock (V = PY/M), turning the equation of exchange into an accounting bridge from a money stock to a flow of spending — provided velocity itself holds steady.
Verdoorn's Law	Growth and Industrial Dynamics	The empirical regularity that labour-productivity growth rises with output growth — a sustained one-point rise in manufacturing output growth adding roughly 0.5 points of productivity growth — so that fast output expansion endogenously induces productivity gains through learning, specialization, and capital deepening.
Vickrey Auction	Mechanism Design and Auction Theory	A sealed-bid auction where the highest bidder wins but pays the second-highest bid, decoupling what you win from what you pay so that bidding your true valuation is the dominant strategy — no rival-modeling needed — and the item reaches whoever values it most.
Vickrey–Clarke–Groves mechanism	Mechanism Design and Auctions	Select an outcome maximizing reported total value and charge Groves transfers that make each agent internalize their effect on others, yielding truthful reporting as a dominant strategy under quasilinear assumptions.
Virtual Economy	Virtual World EconomiesDigital Economics	A governed system of production, scarcity, exchange, and consumption of digital resources within a persistent virtual environment.
Visible balance	International TradeBalance of Payments	The visible trade balance (merchandise trade balance) is that part of the balance of trade figures that refers to international trade in physical goods, but not trade in services; it thus contrasts with the invisible balance.
Volatility Smile	Derivatives and Options Pricing	The pattern that an option's implied volatility varies systematically with strike and maturity rather than being the constant Black-Scholes assumes, tracing a curve whose shape is read as the fingerprint of the market's risk-neutral return distribution and its pricing of tail risk.
Volume Index	Economic StatisticsIndex Numbers	A volume index or quantity index is a numerical time series measure designed to help compare how the production of some class of goods and/or services, taken as a whole, differs between time periods or geographical locations.
Wagner's Law	Public Finance	The empirical regularity that as a country industrializes and per-capita income rises, public expenditure grows faster than GDP so its share of national income climbs — driven by the compounding pull of administrative load, income-elastic demand for merit goods, and Baumol cost-disease.
Wallace Neutrality	Monetary Economics	A conditional irrelevance theorem under which public-liability swaps leave equilibrium prices and real allocations unchanged when fiscal backing is fixed and the assets have no distinguishing services or trading constraints.
Welfare Cost of Business Cycles	Macroeconomic WelfareBusiness CyclesWelfare Economics	The consumption-equivalent reduction in welfare attributed to macroeconomic fluctuations, measured by the uniform consumption change that makes an agent or social criterion indifferent between a cyclical path and a specified smoother counterfactual.
Welfare Cost of Inflation	Monetary EconomicsMacroeconomics	In macroeconomics, the welfare cost of inflation comprises the changes in social welfare caused by inflation.
Wholesale-Funding Run	Banking and Liquidity	A rapid, self-reinforcing withdrawal of short-term funding by a small set of professional creditors who simultaneously refuse to roll over maturing liabilities — coordinated by shared information and driven by the first-mover advantage of a finite liquid-asset pool, draining a firm in days.
Wicksell's theory of capital	Capital TheoryMarginal Productivity Theory	Named after Swedish economist Knut Wicksell (1851-1926), Wicksell's theory of capital examines factor prices as derived from the value of the marginal product.
Williamson tradeoff model	Industrial Organization Economics	The Williamson tradeoff model weighs merger cost efficiencies against monopoly-price welfare losses in antitrust analysis.
Willingness to pay	Welfare and Behavioral Economics	The maximum amount of money or other numeraire an actor would exchange for one unit of a good, service, outcome, or risk change under a declared decision context.
Zero Lower Bound	Monetary Economics	The near-hard floor that stops a central bank cutting its nominal policy rate below zero — because savers can always hold cash yielding 0% — turning the exhaustion of the conventional rate lever into a regime change that forces unconventional easing tools.