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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 Alfred Herbert Gibson) is the historical regularity, seen in gold-standard Britain from roughly 1730 to 1930, that long-term nominal interest rates and the general price level moved together. The "paradox" is that Fisher-type theory predicts rates should track expected inflation — the rate of change of prices — not the level itself. It remains an open puzzle; Barsky and Summers (1988) proposed the leading resolution.

Scope of Application

Gibson's paradox is unusually substrate-bound — the empirical fact lives only in gold-standard Britain, and its scope is the monetary-history subfields that use it.

  • Monetary history and historiography — a canonical regularity of the long-nineteenth-century British record.
  • Macroeconomic theory of the gold standard — the central challenge case for real-side interest-rate theories.
  • History of monetary thought — a testing ground for expectations-formation models (Fisher, Keynes, Friedman).
  • Comparative monetary regimes — the correlation's disappearance under fiat is itself diagnostic, a natural experiment.

Clarity

Naming the paradox keeps three things apart that informal discussion fuses: the Fisher relation between rates and expected inflation, Gibson's correlation between rates and the price level, and the dependence of rates on real-side fundamentals. It shows precisely what is anomalous — a level correlation where theory predicts a rate-of-change one — and pushes the sharper question: what shared driver moves the price level and the real rate jointly, and is it an artifact of the monetary regime?

Manages Complexity

A historian faces a tangle of co-moving nominal series — yields, prices, money stocks, gold flows — any pair of which can be regressed into a "law." Gibson's paradox compresses one slice into a single named target moment, tagged with what makes it anomalous, that every candidate theory must reproduce or explain away. The Barsky-Summers resolution collapses two endogenous series to one shared real-side driver (gold-mining productivity), and the regime furnishes the controlling branch.

Abstract Reasoning

The named anomaly licenses distinctive moves: anomaly-as-detector (using the correlation's presence or absence to probe monetary structure), causal-direction discipline (refusing to infer a direct rate-price link from two endogenous series and hunting an exogenous third driver), boundary-drawing (treating the regime as the licensing condition), and natural-experiment reasoning (contrasting gold-standard and fiat spans to separate regime-specific from regime-invariant relations).

Knowledge Transfer

The empirical fact transfers nowhere — it is a claim about one regime, one country, one span. Within monetary history the methodological lesson transfers as mechanism: invert the anomaly into a regime-detector, refuse to read a causal link off co-moving endogenous aggregates, treat the regime transition as a quasi-experiment. The same discipline applies to the field's other regime-specific stylized facts (the original Phillips curve, the velocity "constant"). Beyond monetary economics only a general caution travels — that long-run correlations can be regime-bound — carried by the parents historical_contingency, path_dependence, and identifiability, never by the paradox's name.

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

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