Old World Trade Diasporas

What explains worldwide, historical patterns of trade diaspora dispersal? In the premodern period, trade diasporas were among the most important communities facilitating cross-cultural exchange over long distances. We collect data on the locations of trade diaspora communities across Eurasia between 600 and 1600 CE, a time period that predates the rise of European economic, military, and colonial hegemony. Our results suggest two general patterns explaining the proliferation of premod-ern trade diasporas. First, diaspora merchants were drawn to wealthy societies to obtain access to high-value luxury goods with complex supply chains. Second, traders sought to establish dias-pora communities in locations that exhibited bioclimatic complementarities to the merchant’s home region, thereby assisting the procurement of relatively rare or uncommon natural resources. We ex-plore the individual-level mechanisms underlying the patterns we observe through the development of an agent-based model that specifies the agents’ (i.e. traders’) rule-based decisions operating in a wealth and resource-differentiated geographic space that represents premodern Eurasia.