Summary and conclusions
From the case studies of various successful merchant groups operating in underdeveloped countries and elsewhere in present-day Antwerp, Amsterdam and New York, we observe that these successful middleman groups share the following adaptive characteristics:
1. Middlemen belong to tightly-knit groups so that middleman exchange—with specialization and division of labor among middlemen—is characterized by personalistic exchange based on kinship, ethnic or religious ties. The greater the degree of trust involved in transactions, the more homogeneous and tightly knit the HMG becomes, e.g. the Yiddish-speaking Hassidic Jews dominate the diamond trade in Antwerp and in New York, while the very religious Jains-Marawari traders dominate the emerald gem trade.
2. Kinship and ethnic ties, as well as shared social norms embedded in these HMGs serve as constraints on the behavior of group members, and hence functioned to provide members with club goods.
3. Wealthy members of the HMGs who are also leaders of their own ethnic communities, especially Chinese and Jewish merchants, played key roles in transmitting cultural values to future generations of merchants via their roles in promoting education, etc
Frank Salter’s comment here:
HMG competitiveness is not due solely to club-like institutions operating in societies with underdeveloped contract law. Two locations of successful HMGs discussed by Landa, Amsterdam and New York, have had developed legal infrastructure for centuries. A cause of this success appears to be individual competitiveness. When traders possess human capital in the form of heritable traits that gives them an individual competitive edge endogamy will reproduce those traits. In addition to institutional synergies, members of HMGs also show strong work ethics and in most cases cited by Landa elevated cognitive ability compared to neighboring ethnic groups. Those traits are partly transmitted culturally in family and ethnic traditions. Landa documents the cultural roles performed by leading HMG traders. But there are also genetic causes of differences in IQ and conscientiousness, to name two characteristics bearing on academic and economic success (Bouchard 1997; Flynn 1991; Gottfredson 1997). At the end of the twentieth century average national IQ accounted for over 50% of the global variation in GDP (Lynn and Vanhanen 2002). The same trend is likely to apply to merchant groups because trading is cognitively demanding. Advantages in heritable human capital are maintained by endogamy by preventing regression to the general population mean (Salter 2008). Where no heritable advantage exists, endogamy is a precondition for such an advantage to evolve through individual or group selection