The 6.6-mile theorem

Claim (verbatim)

The 6.6-mile theorem. In the 13th century, English law adopted a rule for how far apart markets must be — the spacing derived in the classic legal reckoning from a day's return journey on foot, about 6.6 miles. The conjecture joins this statute to the theory of self-organizing spatial equilibria: central-place economics predicts that competing markets space themselves at just such intervals without anyone legislating it, because a market too close to a rival cannot draw a living catchment. If that is right, the law codified an equilibrium rather than creating one, and the geography should show it: English market charters granted before the spacing statute should already exhibit the statutory spacing, with pre-statute nearest-neighbor distances statistically indistinguishable from post-statute ones. A jump in spacing at the statute would mean law made the pattern; continuity means law merely ratified it.

Prediction clause (verbatim)

For each chartered market in the geocoded charter series, compute the nearest-neighbor distance to markets already chartered at its foundation date, split into pre-statute and post-statute cohorts, and compare the two spacing distributions. Primary clause: the pre-statute median nearest-neighbor spacing already lies within one mile of the statutory 6.6-mile norm, and the pre- and post-statute distributions show no significant shift at p < 0.05; a clearly tighter pre-statute spacing that jumps to the statutory value only after the law kills the conjecture. The verdict follows the primary clause.

Kill-dataset (verbatim)

charter geodata pre- and post-statute.

Novelty / leakage triage

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

The dossier partially undermines the conjecture's framing: the 6⅔-mile spacing was already a stated LEGAL norm before any codifying statute — attributed to Bracton and applied in royal charters (Loughborough, 1227) — so pre-statute spacing conformity could reflect early law rather than self-organized equilibrium; the discriminating window is the pre-Bracton charter record. The empirical spacing measurement itself (charter geodata pre/post) was not located as performed, and the Gazetteer of Markets and Fairs provides the enabling GIS dataset.

• 'Gazetteer of Markets and Fairs in England and Wales to 1516' (Centre for Metropolitan History) — Enabling geocoded charter dataset
• Bracton-attributed 6⅔-mile rule applied in 1227 Loughborough charter (Ancient Origins overview) — The rule predates the statute as stated law — framing confound

Predictions

No prediction registered yet.