Exchange Network Topologies and Agent-Based Modeling: Economies of the Sedentary-Period Hohokam

The origins and evolution of market-based economies remain poorly understood in part because the data from nascent markets are scarce and methods available to archaeologists are underdeveloped. Studying how markets evolved is vital for understanding the origins of a process that dominates modern economies around the world and has significant policy implications. We show how refining abstract models of exchange networks with household-scale distributional analyses and regional-scale computational agent-based models (ABMs) can lead to new understandings about the organization of a prehistoric economy. The Sedentary-period Hohokam of central Arizona-particularly for the middle Sacaton phase (A.D. 1020-1100)-have been identified as a middle-range society that traded pottery in a market-based economy, but the structure of their exchange networks is not well understood. We analyzed ceramic data from recent archaeological excavations at two sites in the Phoenix Basin using new network-inspired distributional approaches to evaluate exchange systems. Initial results were then assessed using simulated data generated by an ABM of Hohokam exchange networks. Final results indicated that the best-fitting ABM model configurations were those consistent with openly accessed market-based exchange and contributed new insights into the influence of natural landscape barriers such as the Salt River on exchange in the Phoenix Basin.