Size Upswings of Cities and Polities: Comparisons of World-Systems Since the Bronze Age

This study examines growth and decline phases of cities and polities (states and empires) since 1500 BCE in order to test explanations of the evolution of complexity and hierarchy in world-systems.  World history has long recognized that the population sizes of largest cities as well as the territorial sizes of largest polities go through cyclical growth and decline phases. It has been found that urban and polity upsweeps (large changes in scale) are correlated in time. But the number of these instances of large-scale change (upsweeps) is limited to about 40. Far more numerous are the smaller upswings in which the sizes of the largest city or polity increases but is not significantly larger than earlier increases. This study will examine these upswings and will compare them with upsweeps in ten world regions (Europe, Southwest Asia, Africa, Central Asia and Siberia, East Asia, South Asia, Southeast Asia, Oceania, North and Central America, and South America and Caribbean) since the Bronze Age. We will also use political/military interaction networks as units of comparison and analysis.  And we will examine the temporal relationships between urban and polity upswings and such potential causes of upswings and upsweeps as warfare and trade and the hierarchical or decentralized structure of interaction networks.