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Equity premium puzzle

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.

Core Idea

The equity premium puzzle, formalized by Mehra and Prescott (1985), is that the historical excess return of US equities over bonds — roughly 6 points per year — is orders of magnitude larger than a standard consumption-based asset-pricing model can rationalize at plausible risk aversion. The model prices the premium as compensation for equity's covariance with consumption growth; because that growth is smooth and weakly correlated, matching the premium demands implausible risk aversion of 30-40.

Scope of Application

The equity premium puzzle is a single calibration anomaly scoped to asset pricing, not a recurring mechanism; its reach is depth on one number within a small cluster of consumption-CAPM anomalies.

  • Consumption-based asset pricing — the home turf: the central unsolved calibration target.
  • The risk-free-rate puzzle — its mirror image, the same anomaly from the other leg.
  • Preference-theory research — habit formation, Epstein-Zin, loss aversion, ambiguity aversion.
  • Rare-disaster macro-finance — the branch arguing the postwar sample omits tail risk.
  • Limited-participation asset pricing — denying the representative consumer is the marginal investor.
  • Long-run return measurement — the survivorship-bias branch on the US series.

Clarity

The puzzle relocates the question, converting the vague "equities are risky, so they pay more" into a calibration: one number the model must reproduce from constrained inputs. Naming it makes the order-of-magnitude gap a fact to be explained, and forces every proposed fix to declare which load-bearing assumption it abandons, so rival resolutions can be compared on common ground.

Manages Complexity

Ninety years of returns on hundreds of securities collapse to one confrontation between one number and one model. That compression imposes a fixed branch structure: because the failing model rests on a short, enumerable assumption stack, every resolution must abandon at least one named element — preferences, the consumption tail, the marginal investor, or the data series.

Abstract Reasoning

The puzzle licenses diagnostic backward inference from the size of the miss, assumption-localization that reads each fix as a wager on one layer of an explicit stack, interventionist derivation of differential empirical predictions from each branch, and boundary-drawing that keeps the persistent premium from being misclassified as arbitrage.

Knowledge Transfer

Within asset pricing the puzzle transfers as a live research object — the full apparatus carries — but it is one anomaly, not a recurring mechanism; its reach is depth, not breadth. Beyond it, moving the name strips the model and data (analogy). The genuinely portable content is the parent: a calibrated model diverging from a measured quantity beyond tuning, indicting an assumption, input, or frame. Carry that parent, not the consumption-covariance furniture.

Relationships to Other Abstractions

Local relationship map for Equity premium puzzleParents 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.Equity premium puzzleDOMAINPrime abstraction: Calibration Anomaly — is a decomposition ofCalibrationAnomalyPRIMEDomain-specific abstraction: Risk-Free Rate Puzzle — presupposesRisk-FreeRate PuzzleDOMAIN

Current abstraction Equity premium puzzle Domain-specific

Parents (1) — more general patterns this builds on

  • Equity premium puzzle is a decomposition of Calibration Anomaly Prime

    The Equity Premium Puzzle is the asset-pricing form of a calibration anomaly in which an independently constrained model misses an independently measured target beyond plausible retuning.

Children (1) — more specific cases that build on this

  • Risk-Free Rate Puzzle Domain-specific presupposes Equity premium puzzle

    The Risk-Free Rate Puzzle arises when raising CRRA risk aversion to repair the Equity Premium Puzzle drives the same model's risk-free-rate prediction implausibly high.

Hierarchy path (1) — routes to 1 parentless root

Neighborhood in Abstraction Space

Equity premium puzzle sits in a crowded region of the domain-specific corpus (35th percentile for distinctiveness): several abstractions share nearly its structure, so a description that fits it tends to fit its neighbors too.

Family — Macroeconomic Equilibria & Consumer Demand (19 abstractions)

Nearest neighbors

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