Family chains hug the periphery

Claim (verbatim)

Family chains hug the periphery. This connects transmission genealogy with urban market structure. In a metropole a student could shop among a hundred shaykhs; in a small town the household was the archive. Father-to-son transmission (ʿan abihi ʿan jaddihi) was therefore not primarily piety but a thin-market outcome: where the teaching market was deep, students diversified their chains across the best available masters, and where it was thin, they inherited. Family isnads should concentrate geographically at the edges of the scholarly world, and their share is an inverse index of local intellectual market depth.

Prediction clause (verbatim)

In machine-readable biographical dictionaries, the share of scholars whose recorded transmission includes a father-to-son link is at least 1.5 times higher among scholars based outside the five largest scholarly cities of their era (period-appropriate sets drawn from Baghdad, Damascus, Cairo, Nishapur, Cordoba, Istanbul) than among metropolitan scholars. Primary clause: the 1.5x-or-greater periphery-to-metropole ratio of family-link share; the verdict follows it. Secondary: the gradient steepens with distance from the nearest metropole, proxied by nisba toponyms.

Kill-dataset (verbatim)

Kill: al-Dhahabi's Taʾrikh al-Islam and Siyar Aʿlam al-Nubalaʾ in the OpenITI corpus, where kinship transmission formulas and toponymic nisbas are string-detectable at scale.

Novelty / leakage triage

provisional — model-triaged, shepherd review pending

A provisional first pass authored by the model (Opus), not yet confirmed by the shepherd. It carries the same dated-search requirements as an authoritative verdict but is excluded from every headline figure and cannot underwrite a prediction until a shepherd confirms it. Provisional reading: Adjacent (closely related prior work exists).

[Independent blind re-audit 2026-07-08 (2nd pass, generator-independent, blind to pass 1). DOWNGRADED from the provisional 'novel_unlocated': this adversarial pass located adjacent prior work.] Quantitative analysis of Islamic biographical dictionaries (Bulliet 1970; Romanov 2013 on al-Dhahabi, tracking shifting centres of scholarly influence) and network/center-periphery studies of scholarly lineages exist, and the father-to-son ('an abihi 'an jaddihi) family isnad is a recognized category in hadith studies. What is unlocated is THIS specific economic-geographic claim: that family-link share is >=1.5x higher among scholars based OUTSIDE the top-five scholarly cities than among metropolitan scholars, read as a thin-market (market-depth) outcome, with a distance gradient via nisba toponyms. Prior work quantifies scholarly geography and networks but does not, as far as I found, model family transmission as an inverse index of local teaching-market depth.

• Maxim Romanov, 'Computational Reading of Arabic Biographical Collections' (PhD, Michigan 2013) — data-mining al-Dhahabi, shifting scholarly centres
• Richard Bulliet, quantitative approach to medieval Muslim biographical dictionaries (1970) — foundational method
• 'Institutions and the transmission of upper-tail human capital: scientific lineages across a millennium' (scholarly-lineage networks, center-periphery)

Predictions

No prediction registered yet.