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Brick-stamp Gibrat
Status is derived only from the shepherd-authored triage/prediction data above -- community submissions and claims are a separate overlay and can never change it (see the participation panel below).
Claim (verbatim)
Brick-stamp Gibrat. Gibrat's law — the modern finding that firm growth rates are independent of firm size, which generates the Pareto (power-law) distribution of firm sizes seen in every industrial economy — is here tested two thousand years early. Roman brickyards (figlinae) stamped their products, and the CIL XV corpus of brick stamps preserves output maker by maker over time: an accidental census of an ancient industry. If the Roman building-materials market worked like a modern one — many small producers, a few giants, growth driven by multiplicative shocks rather than by size itself — then stamp counts per figlina should show Pareto-distributed firm sizes, and each yard's growth from period to period should be statistically independent of how big it already was. Modern firm dynamics in the ancient economy, or their absence, becomes directly measurable.
Prediction clause (verbatim)
For each figlina in the CIL XV brick-stamp corpus, count stamps per dated period as an output proxy. Fit a power-law (Pareto) model to the cross-sectional size distribution, and regress period-on-period log growth rates on log size. Primary clause: the Pareto fit is not rejected for the upper tail of figlina sizes, and the coefficient of growth on size is indistinguishable from zero (absolute value below 0.1), satisfying Gibrat; a rejected power law or clearly size-dependent growth kills the conjecture. The verdict follows the primary clause.
Kill-dataset (verbatim)
stamp counts per figlina over time.
Nobody has run this test. The kill-data is named above. If you can run it — or you know the paper that already settles it — claim the kill or submit the prior scholarship. Kills and prior scholarship are credited here, by name, as they come in.
On Inferpedia
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Provenance
Run: Imported conversation (verbatim harvest) · model: claude-fable-5
Origin: operator conversation with Claude Fable 5 at max effort, conducted 2026-07-03, relayed verbatim by the operator into the shepherd session on 2026-07-04. No ModelRun exists for the original generation (it happened outside the pipeline); this transcript file is the canonical capture. Transcript path: docs/generated/conjecture_harvest_fablemax_20260703.md. Model (operator-attested, not pipeline-recorded): claude-fable-5. Novelty disclaimer (verbatim, load-bearing -- rule 4): "Same caveat as before, doubled: at 100 items across all of archaeology and history, some of these will have cousins in the literature I can't check. What I can guarantee is the format — each links two things not normally linked, and each names the dataset or measurement that would kill it."
Novelty / leakage triage
no prior formulation located (search dated 2026-07-05)
Figlina scholarship on CIL XV brick stamps is rich (Helen, Setälä, Bodel: organization, ownership, market structure) and firm-size Gibrat/Pareto theory is mature, but no source was located applying size-distribution or proportional-growth testing to stamp-count data — the join itself appears unmade. No prior formulation located (search dated 2026-07-05).
- Helen 1975, 'Organization of Roman Brick Production in the First and Second Centuries A.D.' — The enabling stamp-corpus scholarship; no statistical firm-dynamics treatment
Predictions
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