Enforcing cooperation among medieval merchants: The Maghribi traders revisited

Abstract

We revisit Greif's (1993) analysis of trade between the 11th-century Maghribi traders and present two different models which bring into play, in an essential way, historical features of the Maghribi's organization which had no role in Greif's own analysis. Our reformulation of the Maghribi's "punishment strategies" incorporates principal components of their actual historical practice and explains why they may have been necessary to sustain cooperation, especially in the presence of uncertainty or imperfect information. We also model "formal friendships," or trade through bilateral and multilateral partnerships, and predict the Maghribi's practice of providing agency services without pecuniary compensation. We are thus able to provide a richer and more accurate picture of how that organization facilitated trade between widely-dispersed traders in the absence of a reliable legal system to enforce merchant contracts.