Cliodynamics

I investigate the geographical consequences of demographic-structural dynamics using a spatially resolved agent-based model of agrarian empires in several Old World regions between 1500 BCE and 1500 CE. I estimate and bound key model parameters from two historical datasets. Although several very large-scale polities (e.g., Roman, Persian, Tang empires) do not arise and certain geographical expansions occur at different times, overall the model suggests that factional civil wars, the result of repeated internal demographic-structural crises, can substantially account for the spread of large-scale agriculture throughout the Old World after the Bronze Age.

A long-standing debate on the dynamics of population growth in human history has become polarized between a Malthusian stance and a Boserupian one. The former tends to view population growth as limited by carrying capacity, dependent on environment and technology, whereas the latter sees population growth itself as a major inducement to social, economic and technological developments. In this paper the authors experiment with approaching this debate by using recent developments in evolutionary theory. According to these, evolutionary principles, as expounded by Charles Darwin and subsequent evolutionary scientists, apply not only to biological evolution but also to social or cultural evolution. Here, the role of genes is taken over by culture and, since culture is much more pliable than our DNA, evolution speeds up. As the only organisms on Earth whose evolution relies as heavily on culture as on genes, humans have become extremely adaptable. Their hyper-adaptability suggest that humans, through their cultural evolution, have managed increasingly to adapt to their own growing population, thus succeeding in accommodating ever-growing numbers. This hypothesis fits the Boserupian approach to population very well but less so the Malthusian one, perhaps indicating a gradual shift from a Malthusian regime to a Boserupian one in human history. The hypothesis is discussed and examined through four case studies: The beginning of farming around Göbekli Tepe in southeast Turkey, the productive farming systems of Tiwanaku in South America, the population crisis of late medieval and early modern Iceland, and the ‘collapse’ of Rapa Nui (Easter Island).

Secular cycles are 2-3 century oscillations in population associated with periodic state breakdown. Turchin and Nefedov (2009) find two secular cycles in England: the Plantagenet (1150–1485) and Tudor-Stuart (1485–1730). This paper proposes modified dating for these cycles (1070–1485 and 1485–1690) and two adjacent cycles: Anglo-Saxon (ca. 880–1070) and mercantile (1690–undetermined). Several mathematical models for secular cycles were investigated for their ability to model trends in population, state strength, elite number and internal instability during the Plantagenet and Tudor-Stuart cycles with the modified dating. The demographic-fiscal model (Turchin 2003) uses just six adjustable parameters and gave as good a fit to the population data as a polynomial model with ten parameters. Sociopolitical instability has been proposed as the primary factor in delayed population recovery following secular decline. This did not seem to be the case for England, at least when instability was measured in terms of large-scale events. For such events the dominant pattern was the fathers and sons cycle, not the much longer secular cycle.

Forum on 'Does Capitalism Have a Future? That Is the Research Question In Response to Bruce Scott'

A Review of Big Gods: How Religion Transformed Cooperation and Conflict by Ara Norenzayan (Princeton University Press, 2013)