SECULAR CYCLES: LONG-TERM OSCILLATIONS IN ECONOMIC AND SOCIAL STRUCTURES OF AGRARIAN SOCIETIES

One particularly interesting dynamic pattern in history is the oscillation of centralization and decentralization of political power, seemingly affecting all hierarchical macrosystems, from systems of chiefdoms to world empires. What sociopolitical mechanisms may explain these dynamics? I will present some mathematical models and data that address this question. The decline and fall of the Roman Empire, recurrent collapses of Mesopotamian civilizations, and rise and demise of great powers – such historical events excite lay public’s imagination and provide fodder for controversies about possible causes among historians. Explanations range from particularistic, specific for each instance of collapse (e.g., the role of Christianity in the fall of Rome [1]), to very general such as Joseph Tainter’s theory that diminishing returns on sociopolitical complexity lead to imperial decline and collapse [2]. Here I focus on one explanation of recurrent waves of state breakdown experienced by the agrarian states and empires, the demographic-structural theory [3, 4]