The plucking model of the papyri

Claim (verbatim)

The plucking model of the papyri. Milton Friedman's plucking model of business cycles holds that an economy runs along a capacity ceiling from which recessions pluck output downward: deep slumps rebound fast, while booms say nothing about the next bust. This conjecture transposes that asymmetry onto documentary papyrology's roughly 77,000 dated documents. The mechanism is that documentary output was pinned to an administrative-capacity ceiling — scribes, offices, taxation routines — from which plagues, revolts, and fiscal crises plucked it downward, after which the machinery re-expanded toward the same ceiling. The depth of a documentary collapse should therefore predict the speed of the subsequent recovery, while the size of the preceding boom should predict nothing about the coming contraction. The expected signature is a strong positive depth-to-rebound correlation alongside a near-zero boom-to-bust correlation — an asymmetry no symmetric cycle model can produce.

Prediction clause (verbatim)

Binning the ~77k dated documents into 25-year bins over 300 BCE-700 CE and detrending, contraction episodes with a peak-to-trough fall of at least 15% are followed by recoveries whose 50-year rebound rates correlate with trough depth at Spearman rho >= +0.5, while the preceding 50-year growth rate correlates with the coming contraction's depth at |rho| <= 0.2; the asymmetry gap between the two correlations is >= 0.4.

Kill-dataset (verbatim)

Kill: papyri.info documentary catalogue dates (~77k records, in house); a symmetric correlation structure (booms predicting busts as strongly as busts predict recoveries) or an inverted one kills it.

Novelty / leakage triage

anticipated in the literature — this exact test has never been run

CORRECTED 2026-07-05 after independent verification (conjectures_batch3_verification.md, MEDIUM finding): the original rationale attributed arXiv 2306.01552 to 'Kose et al.', dropping the dossier's own 'or similar' hedge; the actual authors are Kohlscheen, Moessner & Rees. Substance unchanged: the plucking asymmetry is tested on multi-century historical output series (Maddison data, six centuries) - same method, neighboring long-run corpus - but no application to documentary/papyrological production counts was located. Bagnall's standard methodological cautions on papyri count series must be engaged by any resolution.

• Kohlscheen, Moessner & Rees, 'The shape of business cycles: a cross-country analysis of Friedman's plucking theory' (arXiv 2306.01552) — Multi-century historical plucking test, GDP data; authorship corrected post-verification
• Bagnall, 'Reading Papyri, Writing Ancient History' (BMCR review) — The discipline's own count-series cautions

Predictions

No prediction registered yet.