Skip to content

Gibson's Paradox

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.

Core Idea

Gibson's paradox (named by Keynes after British economist Alfred Herbert Gibson, 1923) is the historical empirical regularity, observed primarily in the United Kingdom during the gold-standard era from roughly 1730 to 1930, that long-term nominal interest rates and the general price level moved together — high price levels coincided with high long-term rates, low price levels with low rates. The paradox label marks the contradiction with Fisher-type monetary theory, which predicts that nominal rates should correlate with the rate of change of prices (inflation) rather than with the price level itself; under the Fisher equation, a positive correlation between rates and the price level can only arise if expected inflation is positively correlated with the level, which requires special and non-obvious assumptions about expectations formation.

The paradox is a domain-specific puzzle in monetary history rather than a resolved structural pattern: multiple candidate resolutions have been proposed without achieving consensus. Barsky and Summers (1988) offered the most influential attempt, arguing that under a gold standard both the price level and the real interest rate are jointly driven by the productivity of gold-mining and capital — when gold is cheap to produce, prices rise and real returns fall; when costly, prices fall and real returns rise — producing the observed correlation as a joint consequence of a shared real-side driver rather than any direct causal link between rates and price levels. A further diagnostic feature of the paradox is its regime-specificity: the positive correlation between long rates and price levels disappears after the abandonment of the gold standard in the twentieth century, implying the relationship was an artifact of the institutional structure of commodity money rather than a deep behavioural law of interest-rate determination.

Structural Signature

Sig role-phrases:

  • the commodity-money regime — the gold-standard institutional substrate that sets the conditions for the relationship
  • the long-run historical sample — roughly 1730–1930 Britain, the span over which the observations are drawn
  • the two endogenous nominal series — long-term nominal interest rates and the general price level
  • the anomalous level correlation — a persistent positive co-movement of rates with the price level, not with its rate of change
  • the Fisher-theory violation — the contradiction: theory predicts rates track expected inflation, so a level correlation needs special expectations assumptions
  • the shared real-side driver — the candidate resolution (Barsky-Summers): gold-mining-and-capital productivity moves price level and real rate together, the correlation a side effect of one exogenous cause
  • the regime-change switch — abandonment of the gold standard removes the joint driver and the correlation vanishes, evidencing its regime-specificity
  • the natural-experiment contrast — the gold-standard span versus the fiat span used to separate regime-specific from regime-invariant relationships

What It Is Not

  • Not a confirmation of the Fisher relation. Fisher predicts nominal rates track expected inflation — the rate of change of prices. Gibson's correlation is between rates and the price level. That a level correlation appears where theory predicts only a rate-of-change one is exactly what makes the regularity anomalous; reading it as "rates follow money" misses the violation that names the paradox.
  • Not a resolved or settled mechanism. It remains an open puzzle of monetary history. Several resolutions have been proposed — most influentially the Barsky-Summers shared-real-driver account — but none commands consensus. Treating any single explanation as established overstates where the literature stands.
  • Not a universal behavioural law of interest-rate determination. The correlation is regime-specific: it holds under the gold standard and vanishes under fiat money. It is a stylized fact bound to the commodity-money apparatus, effectively a natural experiment in monetary regimes — not a timeless dynamic of how rates are set.
  • Not evidence of a direct rate-to-price causal link. The co-movement of two endogenous nominal aggregates does not establish that rates move prices or prices move rates. The leading resolution attributes both to an exogenous third driver — gold-mining-and-capital productivity moving the price level and the real rate together — so the correlation is a side effect of a shared cause, not a causal relation between the two series.
  • Not a logical contradiction. Despite the name, it is not self-contradictory or impossible; it is a robust empirical regularity that contradicts the prediction of a theory (Fisher's). The "paradox" marks the gap between observation and expected theory, not an internal inconsistency in the data.

Scope of Application

Gibson's paradox is unusually substrate-bound: the empirical correlation itself lives in exactly one place — long-term nominal rates and the price level in gold-standard Britain — so its scope is the monetary-history subfields where that fact and the methodological lesson it carries are used; the general "long-run correlations can be regime-specific" caution travels under the parent primes (historical_contingency, path_dependence, identifiability), not under the paradox's name.

  • Monetary history and historiography — the home turf: one of the canonical empirical regularities of the long-nineteenth-century British monetary record, debated in the gold-standard literature.
  • Macroeconomic theory of the gold standard — the central challenge case for theories deriving interest-rate dynamics from real-side fundamentals (gold-mining productivity, real returns on capital), via the Barsky-Summers shared-driver resolution.
  • History of monetary thought — a testing ground for expectations-formation models, treated formally by Fisher, Keynes, Friedman & Schwartz, and Barsky & Summers.
  • Comparative monetary regimes — the disappearance of the correlation after the gold standard is itself diagnostic, used to argue the relationship was regime-specific rather than a deep behavioural law, effectively a natural experiment in monetary regimes.

Clarity

Naming the paradox keeps three things apart that informal monetary discussion routinely fuses: the Fisher relation between nominal rates and expected inflation; Gibson's correlation between nominal rates and the price level; and the dependence of rates on real-side fundamentals in the Wicksellian natural-rate framework. Without the label, a positive co-movement of consol yields and the price index reads as confirmation of "rates follow money," and the violation of Fisher goes unnoticed. With it, the analyst sees precisely what is anomalous — a level correlation where theory predicts only a rate-of-change one — and is pushed toward the sharper question: not "do rates and prices move together?" but "what shared driver could move the price level and the real interest rate jointly, and is that driver an artifact of the monetary regime?"

Its second clarifying contribution is to make the role of the institutional substrate legible. The correlation was a feature of the gold-standard era and did not survive the transition to fiat money, which reframes the puzzle from a candidate behavioral law of interest-rate determination into a regime-specific stylized fact — effectively a natural experiment in monetary regimes. That recasting tells a monetary historian where to look for the mechanism (the commodity-money apparatus, gold-mining productivity) rather than in universal expectations dynamics, and it warns against reading a deep law off a long-run correlation between two endogenous nominal aggregates without first accounting for the regime that generated them.

Manages Complexity

A monetary historian confronting two centuries of gold-standard data faces a tangle of co-moving nominal series — consol yields, wholesale prices, money stocks, gold flows, real returns on capital — any pair of which can be regressed against another to manufacture a "law." Gibson's paradox compresses one slice of that tangle into a single named target moment: a positive correlation between long-term nominal rates and the price level, tagged with exactly what makes it anomalous (a level correlation where Fisher predicts only a rate-of-change one). Instead of carrying the whole undifferentiated co-movement of nineteenth-century aggregates, the analyst carries one stylized fact that every candidate theory of interest-rate determination must either reproduce or explain away. The puzzle becomes the index against which models are scored, so the sprawling historical record is reduced to a pass/fail check on a single moment.

The compression deepens through the structure the resolutions impose. Barsky and Summers collapse two endogenous series to one shared real-side driver: gold-mining-and-capital productivity moves the price level and the real interest rate together, so the observed correlation falls out as a side effect of a single exogenous cause rather than a direct rate-to-price link. That converts a two-variable correlational mystery into a one-cause account the analyst can track with a single quantity (the cost of producing gold). And the regime-specificity furnishes the controlling branch: because the correlation appears under commodity money and vanishes under fiat, the historian reads the monetary regime as a switch that determines whether the relationship is even present. So the question "do rates and prices move together, and why?" reduces to a short decision — which regime generated the sample, and is a shared real-side driver active under it — letting the analyst predict the presence or absence of Gibson's correlation from the institutional setup alone, rather than re-litigating expectations dynamics for every span of the historical record.

Abstract Reasoning

Gibson's paradox, as a named anomaly, licenses reasoning moves that are distinctive precisely because they trade on a theory-violating correlation rather than a confirmed law.

Diagnostic — anomaly-as-detector. The primary move is to use the paradox's presence or absence as a probe of monetary structure. Confronted with two co-moving nineteenth-century nominal series, the analyst does not read the correlation as "rates follow money"; instead the move is to check which correlation it is — rates with the price level (Gibson) or rates with the rate of change of prices (Fisher) — and a level correlation is read as a fingerprint of a commodity-money regime in which a shared real-side driver is operating. The correlation is thus inverted from confirmation into evidence: its specific anomalous form points back to the gold-mining-and-capital productivity channel as the likely common cause, because that is the mechanism known to move price level and real rate together. Equally, the disappearance of the correlation in a later sample is itself a positive finding — it diagnoses a regime change, telling the historian that the institutional substrate generating the relationship has been switched off.

Causal-direction discipline (a boundary move on inference). The paradox trains a refusal: from a correlation between two endogenous nominal aggregates, the analyst declines to infer a direct rate→price or price→rate link, and instead searches for an exogenous third driver that moves both. The reasoning runs "two endogenous series co-move → suspect a shared upstream cause → identify the regime-specific candidate (gold productivity) → check whether that candidate is even active in this sample." This is a guard against the easy manufacture of "laws" from any pair of long-run series, and its payoff is a sharp pass/fail test that every candidate interest-rate theory must clear.

Boundary-drawing — regime as the licensing condition. The central applicability move is to ask, before invoking or expecting Gibson's correlation at all, which monetary regime generated the sample. Under commodity money with a shared real-side driver the correlation is predicted present; under fiat money, with that joint driver removed and the Fisher channel dominant, it is predicted absent. The regime is treated as a switch, so the analyst predicts the presence or absence of the relationship from the institutional setup alone, and treats a Gibson-style correlation found outside the gold-standard regime as a spurious artifact to be explained away rather than a law to be honored. This also delimits the concept's reach: it is a claim about long-term nominal rates and price levels under commodity money, and the analyst does not extend it to short rates, to inflation-rate relationships, or to other regimes.

Comparative / natural-experiment reasoning. Because the relationship appears in one regime and vanishes in another, the move is to treat the regime transition as a quasi-experiment: contrast the gold-standard span against the fiat span to separate what is regime-specific from what is regime-invariant in interest-rate determination. The collapse of the correlation across the boundary is the experimental contrast that licenses attributing it to the commodity-money apparatus rather than to universal expectations dynamics.

Knowledge Transfer

Gibson's paradox is unusually substrate-bound even for a domain-specific abstraction: it is a specific historical correlation — long-term nominal rates and the price level co-moving in gold-standard Britain — and the empirical fact itself transfers nowhere, because it is a claim about one regime, one country, and one span of years. What transfers within the home domain is not the correlation but the methodological lesson the anomaly carries, and there it transfers as mechanism. The reasoning moves — invert the anomaly into a regime-detector (a level correlation fingerprints commodity money and a shared real-side driver; the correlation's disappearance diagnoses a regime change); refuse to read a direct causal link from two co-moving endogenous nominal aggregates and instead hunt the exogenous third driver; treat the regime as the licensing condition and the regime transition as a quasi-experiment — carry intact across monetary history and empirical macro. So the same discipline applies to the field's other regime-specific stylized facts: the original Phillips curve that dissolved after the 1960s, the velocity-of-money "constant" that shifted in the early 1980s, the term-structure relationships that changed with central-bank operating procedures. Gibson's paradox is the paradigm case of the genus — a stylized fact that resists naive theoretical absorption because it is an artifact of an institutional substrate — and that genus is what travels among monetary historians.

Beyond monetary economics there is essentially no cross-substrate transfer of the mechanism to characterise, and honesty requires saying so rather than manufacturing one: the gold-mining-productivity channel, the consol-yield-versus-price-level correlation, and the commodity-money apparatus have no analogue outside their substrate, and the entry claims no extensions beyond it. The one thing that does generalise is not the paradox but a general methodological caution carried by parent primes: a long-run correlation between endogenous variables can be regime-specific and dissolve when the institutional regime changes, so one cannot read a behavioural law off such a correlation without accounting for the substrate that generated it. That caution is a co-instance of patterns already in the catalog — historical_contingency and path_dependence (the outcome is an artifact of a particular institutional history, not a timeless law) and the inference-discipline around identifiability and evidence (two endogenous series cannot identify a causal direction without an exogenous driver). When the lesson is needed in another field — say, a biologist or a sociologist tempted to read a deep law off a long historical correlation — it should be carried by those parents, as the general point that correlations can be regime-bound, not by any invocation of "Gibson's paradox," which names a particular monetary episode and nothing portable. There is, in short, no metaphorical reach worth endorsing here: the empirical content stays home, and the only travelling cargo is the methodological moral, which belongs to the contingency-and-identifiability primes one level up (see Structural Core vs. Domain Accent).

Examples

Canonical

The defining instance is the correlation A. H. Gibson documented in 1923 and Keynes named in his Treatise on Money (1930): plotting the yield on British consols against a wholesale price index over roughly two centuries of the gold-standard era shows the two long series drifting up and down together — high price levels accompanied by high long rates, low levels by low rates. What makes this the textbook anomaly is the specific form of the correlation. Fisher's theory says nominal rates should track expected inflation (the rate of change of prices), so nominal rates and the price level should show no such persistent link. Yet the level correlation is one of the more robust regularities of the British monetary record. Keynes called it "one of the most completely established empirical facts in the whole field of quantitative economics," precisely because it defied the reigning theoretical prediction.

Mapped back: The gold-standard span is the commodity-money regime and the long-run historical sample; consol yields and the price index are the two endogenous nominal series. Their persistent co-movement is the anomalous level correlation, and its clash with Fisher — a level link where theory allows only a rate-of-change one — is the Fisher-theory violation that earns the "paradox" label.

Applied / In Practice

Barsky and Summers deployed the framework in "Gibson's Paradox and the Gold Standard" (Journal of Political Economy, 1988). Rather than posit a direct rate-to-price link, they argued that under a gold standard the price level and the real interest rate are jointly driven by the gold market: the relative price of gold is pinned by convention, so shifts in the productivity of gold mining versus capital move the general price level and real returns together. When gold is cheap to produce, prices rise and real rates fall; when costly, prices fall and real rates rise — generating Gibson's correlation as a byproduct of one exogenous real-side cause. They reinforced the account by noting the correlation's absence under fiat money, treating the gold-standard-versus-fiat contrast as a natural experiment that pins the effect on the commodity-money institution.

Mapped back: The gold-mining-versus-capital productivity channel is the shared real-side driver that resolves the correlation without a direct rate→price link. Attributing the co-movement to that exogenous cause is the causal-direction discipline; using the gold-standard-to-fiat break is the regime-change switch and the natural-experiment contrast, isolating what is regime-specific in interest-rate determination.

Structural Tensions

T1: Confirmation versus anomaly-as-detector (which way the correlation points). The whole diagnostic value of Gibson's paradox comes from inverting a correlation from evidence-for into evidence-of: the naive reading treats co-moving rates and prices as confirming "rates follow money," while the paradox reads the specific form of the correlation — a level link where Fisher allows only a rate-of-change one — as a fingerprint of a commodity-money regime with a shared real-side driver. This inversion is powerful but it cuts both ways: once an analyst is trained to read the correlation as a regime-detector, the same data that a Fisherian counts as confirmation and the paradox counts as anomaly are held apart only by the theory one brings. The correlation does not announce which role it plays; the interpretation is imposed. Diagnostic: Is the co-movement being read as confirmation of a rate-follows-money law, or as the anomalous level signature that fingerprints a commodity-money regime — and which theory is doing the assigning?

T2: A rock-solid fact versus an unresolved cause (the datum outruns its explanation). Keynes called it "one of the most completely established empirical facts in the whole field of quantitative economics," and the empirical regularity is genuinely robust across two centuries of British data. Yet no candidate resolution commands consensus — Barsky-Summers is the most influential, not the settled, account. The tension is a mismatch of confidence levels: the phenomenon is about as certain as macro-history offers, while the mechanism behind it remains an open puzzle. This makes the paradox unusually easy to state and unusually hard to close, and it warns against the reflex of treating any single explanation (or the analyst's favorite) as established merely because the fact it explains is so firmly established. Diagnostic: Is the claim being asserted the correlation itself (near-certain) or a particular mechanism for it (contested) — and is the confidence appropriate to which?

T3: Refusing the direct link versus positing an unobservable shared driver (discipline that can overreach). The paradox trains a healthy refusal: from two co-moving endogenous nominal series, decline to infer a direct rate→price or price→rate link and instead hunt an exogenous third driver. But the disciplined move substitutes one hard-to-verify claim for another — the shared real-side driver (gold-mining-and-capital productivity) is itself difficult to measure independently, so the resolution risks being a posited common cause chosen because it would generate the correlation rather than one confirmed to be active. The refusal to over-read the correlation is sound, yet the replacement account can smuggle in an equally unfalsifiable exogenous variable. The rigor lives in demanding the third driver; the risk lives in accepting whichever third driver conveniently fits. Diagnostic: Is the exogenous shared driver independently measured and shown active in this sample, or inferred only from the fact that it would reproduce the correlation?

T4: Regime as a clean switch versus a boundary drawn by the phenomenon (tautology risk). The regime-specificity is the framework's sharpest tool: commodity money predicts the correlation present, fiat predicts it absent, and the transition is a quasi-experiment isolating what is regime-specific. But the monetary "regime" and the presence of the correlation are defined close enough together that the natural-experiment logic can slide toward circularity — if the regime boundary is located partly by where the correlation appears and disappears, then attributing the correlation to the regime explains a phenomenon partly by the thing it defines. The clean switch is a genuine analytic gain only if the regime is characterized institutionally (gold convertibility, the commodity-money apparatus) independently of the correlation it is meant to explain. Diagnostic: Is the monetary regime identified by its institutional structure independently of Gibson's correlation, or is the regime boundary being read off the very correlation it is invoked to explain?

T5: Autonomy versus reduction (a named monetary episode or the portable methodological moral). Gibson's paradox is a specific historical correlation — long-term nominal rates and the price level in gold-standard Britain — and the empirical fact itself travels nowhere; it names one country, one regime, one span of years. Within monetary history the methodological lesson it carries transfers as mechanism to the field's other regime-bound stylized facts (the original Phillips curve, the velocity "constant," term-structure relationships). But beyond that substrate the paradox as named carries nothing; what generalizes is the parent caution — a long-run correlation between endogenous variables can be regime-specific and dissolve when the institution changes — belonging to historical_contingency, path_dependence, and identifiability. Invoking "Gibson's paradox" for a biologist's or sociologist's spurious historical correlation borrows a monetary label for a contingency-and-identifiability point. Diagnostic: Resolve toward the parents (historical_contingency, path_dependence, identifiability) when carrying the "correlations can be regime-bound" moral to another field; toward the named paradox only when scoring a theory of interest-rate determination against the actual gold-standard record.

Structural–Framed Character

Gibson's paradox sits at the mixed position on the structural–framed spectrum, and it is the instructive contrast to a mixed-structural regularity like Gibrat's law: also a discovered empirical regularity of economics, which pulls toward structure, but one so bound to a particular human institutional regime — and so devoid of any literally-transferring mechanism — that it lands squarely in the middle rather than toward the structural end. On evaluative_weight it points structural: the correlation between long rates and the price level convicts and praises nothing — it is a stylized fact, not a normative verdict — with the mild caveat that the very word "paradox" embeds a theory-relative anomaly judgment (a violation of Fisher's prediction), which is an anomaly-relative-to-a-theory tag rather than a fact-of-nature description. The pivotal criterion is human_practice_bound, and here it points framed in a way Gibrat's law does not: the regularity is constituted by the commodity-money apparatus and literally dissolves when that regime is removed — the regime-change switch is the entry's own centerpiece, the correlation vanishing under fiat money — so, unlike a regularity that also governs observer-free biological body sizes, this one runs only inside a specific human institution and has no non-institutional instance. Institutional_origin is correspondingly framed: the entry itself concludes the correlation is "an artifact of the institutional structure of commodity money rather than a deep behavioural law," so its origin is a particular monetary history, not a substrate-neutral fact. On vocab_travels it scores framed: consol yields, the price level, gold-mining-and-capital productivity, the Fisher violation, the commodity-money regime are all pinned to monetary economics and the empirical fact itself travels nowhere — one country, one regime, one span of years. On import_vs_recognize it is the most framed of the criteria: there is no cross-substrate recognition of the same mechanism at all — within monetary history only the methodological lesson transfers to sibling regime-bound stylized facts, and beyond it nothing of the paradox travels except a general caution that belongs to parent primes.

What holds it in mixed rather than framed-leaning is that it remains a genuine, evaluatively neutral, discovered regularity — a robust correlation that ran in the world within its regime, observed rather than constructed (a regression merely tests it), unlike an evaluative label or a classificatory catalog device — while what keeps it well short of mixed-structural is that its every distinctive feature is regime-bound and its only portable content is a methodological moral owned by more general primes. The one portable structural skeleton is regime-contingent correlation — an observed co-movement that is an artifact of an institutional regime and dissolves when the regime changes (paired with the identifiability discipline that two endogenous series cannot fix a causal direction without an exogenous driver). It is what Gibson's paradox instantiates from its umbrella parents (historical_contingency, path_dependence, identifiability), not what makes "Gibson's paradox" itself travel: the cross-domain reach belongs to those contingency-and-identifiability parents, while the gold-standard episode, the consol-yield-versus-price-level fact, and the shared-real-driver resolution stay home. Its character: a genuine, evaluatively neutral, discovered economic regularity that is nonetheless constituted by a specific commodity-money institution and vanishes when it is removed — structural only in the regime-contingent-correlation skeleton it borrows from its historical-contingency umbrella, and mixed rather than more-structural because everything distinctive about the named paradox is an artifact of one monetary regime.

Structural Core vs. Domain Accent

This section decides why Gibson's paradox is a domain-specific abstraction and not a prime — an extreme case, because the empirical fact itself travels nowhere and the only portable content is a methodological moral already owned by parent primes.

What is skeletal (could lift toward a cross-domain prime). Strip the monetary history and a thin methodological structure survives: an observed long-run correlation between endogenous variables can be an artifact of an institutional regime and dissolve when that regime changes — so a behavioural law cannot be read off such a correlation without accounting for the substrate that generated it, and two endogenous series cannot fix a causal direction without an exogenous driver. The portable pieces are abstract — a regime-conditioned correlation, its dissolution across a regime boundary, and the identification discipline against inferring causation from co-moving endogenous aggregates. That skeleton is genuinely substrate-portable, which is why it is already carried in the catalog by the parents Gibson's paradox instantiates — historical_contingency and path_dependence (the outcome is an artifact of a particular institutional history, not a timeless law) and identifiability (two endogenous series cannot identify a causal direction without an exogenous driver). It is the caution Gibson's paradox shares; it is not what makes the paradox distinctive.

What is domain-bound. Everything that makes it Gibson's paradox in particular is monetary-history furniture, and it is unusually total: the commodity-money (gold-standard) regime; the ~1730–1930 British sample; the two endogenous nominal series (consol yields and the price level); the anomalous level correlation and its Fisher-theory violation; the shared-real-side-driver (Barsky-Summers gold-mining-and-capital productivity) resolution; and the regime-change switch by which the correlation vanishes under fiat. The decisive test: the empirical fact itself transfers nowhere — it is a claim about one country, one regime, one span of years — and there is no analogue of the gold-mining channel or the consol-yield-versus-price-level correlation outside its substrate. Strip the commodity-money apparatus and the correlation literally dissolves (that is the paradox's own centerpiece), so the phenomenon is constituted by, and cannot outlive, the very monetary institution the prime bar asks it to shed.

Why this does not clear the prime bar. A prime's vocabulary travels and its transfer is recognition of the same mechanism, not analogy. Gibson's paradox is unusually substrate-bound even among domain-specific abstractions. Within monetary history not the correlation but the methodological lesson transfers as mechanism — invert the anomaly into a regime-detector, refuse a direct causal link between co-moving endogenous aggregates and hunt the exogenous third driver, treat the regime transition as a quasi-experiment — and that discipline carries to the field's other regime-specific stylized facts (the original Phillips curve that dissolved after the 1960s, the velocity "constant" that shifted in the early 1980s, term-structure relationships that changed with central-bank procedures). Gibson's paradox is the paradigm case of that genus. Beyond monetary economics there is essentially no cross-substrate transfer of the mechanism to characterize: the empirical content stays home and the paradox as named carries nothing portable. What generalizes is only the general caution — correlations can be regime-bound — which belongs to historical_contingency, path_dependence, and identifiability, and which should be carried by those parents (for, say, a biologist or sociologist tempted to read a deep law off a long historical correlation), never by invoking "Gibson's paradox." The cross-domain reach belongs entirely to the contingency-and-identifiability parents; the named entry is a particular monetary episode with no travelling cargo of its own — which is exactly what keeps it, decisively, below the prime bar.

Relationships to Other Abstractions

Local relationship map for Gibson's ParadoxParents appear above the current abstraction, mutual partners to the right, and children below. Node labels state whether each abstraction is prime or domain-specific; colors identify relation types.Gibson's ParadoxDOMAINDomain-specific abstraction: Interest Rate — is part ofInterest RateDOMAINDomain-specific abstraction: Real vs. Nominal Value Distinction — is part ofReal vs. Nomina…DOMAINPrime abstraction: Correlation — is a decomposition ofCorrelationPRIMEPrime abstraction: Identifiability — is a decomposition ofIdentifiabilityPRIME

Current abstraction Gibson's Paradox Domain-specific

Parents (4) — more general patterns this builds on

  • Gibson's Paradox is part of Interest Rate Domain-specific

    Gibson's paradox contains the long-term nominal interest-rate series whose co-movement with the price level constitutes the historical anomaly.

  • Gibson's Paradox is part of Real vs. Nominal Value Distinction Domain-specific

    Gibson's paradox contains the nominal-versus-real rate and level-versus- change distinctions that make its correlation violate the Fisher relation.

  • Gibson's Paradox is a decomposition of Correlation Prime

    Removing the monetary history leaves systematic co-variation between two observed series with no licensed causal direction.

  • Gibson's Paradox is a decomposition of Identifiability Prime

    Stripped of the monetary frame, the same observed co-movement is compatible with multiple internal causal structures and cannot uniquely recover one.

Hierarchy paths (5) — routes to 5 parentless roots

Not to Be Confused With

  • The Fisher relation / Fisher effect. The theory that nominal interest rates track expected inflation — the rate of change of prices. Gibson's correlation is between rates and the price level; that a level correlation appears where Fisher predicts only a rate-of-change one is exactly what earns the "paradox" label. Reading Gibson's fact as confirming Fisher misses the violation that defines it. Tell: is the claim rates ~ expected inflation / rate of change (Fisher), or rates co-moving with the price level itself (Gibson's paradox)?

  • The Wicksellian natural-rate framework. The theory that interest rates are governed by real-side fundamentals — the natural rate of return on capital. It is the lens the Barsky-Summers resolution draws on and it neighbors the puzzle, but it is a theory of rate determination, not the empirical anomaly to be explained. Tell: is it a theory of how real fundamentals set the natural rate (Wicksell), or the specific rates-track-price-level empirical regularity (Gibson's paradox)?

  • A logical paradox / self-contradiction. Despite the name, Gibson's paradox is not internally inconsistent or impossible: it is a robust empirical regularity that contradicts a theory's prediction (Fisher's). The "paradox" marks the gap between observation and expected theory, not a contradiction in the data. Namesake trap on "paradox." Tell: is it an internal impossibility (logical paradox), or a solid observation clashing with what a theory predicts (Gibson's paradox)?

  • Sibling regime-bound stylized facts (the original Phillips curve, the velocity "constant," term-structure relationships). Other empirical correlations that dissolved when the institutional or policy regime changed — same genus (a regime-specific stylized fact resisting naive theoretical absorption), different facts. Gibson's paradox is the paradigm case of that genus, not identical to its siblings. Tell: is it a different regime-bound correlation that later broke (Phillips curve, velocity constant), or specifically the gold-standard rates-vs-price-level fact (Gibson's paradox)?

  • A direct rate-to-price causal link (the spurious reading). The mistaken inference that rates move prices, or prices move rates, because the two series co-move. Gibson's leading resolution attributes both to an exogenous third driver (gold-mining-and-capital productivity), making the correlation a side effect of a shared cause, not a causal relation between the series. Contrast case. Tell: is one series claimed to cause the other (direct causal link), or are two endogenous series co-moving under a shared exogenous driver (Gibson's paradox)?

  • The contingency-and-identifiability parents (historical_contingency, path_dependence, identifiability). The substrate-neutral caution the paradox instantiates — a long-run correlation between endogenous variables can be regime-specific and dissolve when the institution changes, and two endogenous series cannot fix a causal direction without an exogenous driver. This is the only portable content; the gold-standard fact itself travels nowhere. Tell: strip the monetary episode and what remains — correlations can be regime-bound, and co-movement is not causation — is carried by these parents, not by "Gibson's paradox." (Treated fully in a later section.)

Neighborhood in Abstraction Space

Gibson's Paradox sits in a sparse region of the domain-specific corpus (60th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Macroeconomic Puzzles & Long-Run Relations (5 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-07-12