Entropic Cities The Paradox of Urbanism in Ancient Mesopotamia

The growth of cities in antiquity is paradoxical: before modern health and sanitation standards, early urban dwellers suffered high mortality as a result of epidemics and chronic diseases arising, respectively, from propinquity and poor sanitation. At the same time, lower-status individuals within those cities would have endured depressed birth rates because, typically, many toiled in partially or fully dependent occupations not conducive to early marriage or stable families. The interplay between these compounding forces implies that early cities would not have been viable over the long term and could not have grown without a continual flow of immigrants. The early cities of Mesopotamia were no exception. In an earlier publication, I argued that the growth of the first centers that emerged in the alluvial lowlands of the Tigris and Euphrates Rivers during the fourth millennium BC was predicated on migratory inflows that took place, in part, in the context of self-amplifying cycles whereby the replacement of imported commodities with locally made, mass-produced substitutes catalyzed increases in specialization, employment, market size, and trade (Smithian growth). In this article, I expand on these ideas, explore their applicability to later periods of Mesopotamian history, and consider further iterations of substitution-fueled growth cycles in those periods.