In Hollywood, sequels and second acts are usually not as good as the first version. Social science, fortunately, does not always work the same way. Secular Cycles is a sequel to Jack Goldstone's Revolution and Rebellion in the Early Modern World (1991) that follows, in turn, earlier work by Malthus, LeRoy Ladurie, and Postan. The basic idea is that history need not be a confusing morass of details, proper names, and obscure places. Theoretical interpretation, fixed on population dynamics and its implications for social and political-economic processes, can be applied in order to make sense of a seemingly bewildering mass of personalities, conflicts, and events. Moreover, since the processes that affect population dynamics tend not to be restricted to national or imperial boundaries, some element of synchronicity across large regions on the scale of Eurasia is to expected. Burmese, Ottoman, and English history, for example, may be more similar than we have conventionally suspected once we put aside the geographical and cultural differences and focus on the population dynamics interacting with other processes, such as tax collection, inflation, and domestic revolts.
The central dynamic in history, it is argued, is population growth within the context of its resource base. When populations exceed their carrying capacities, and ceteris paribus, a number of things are likely to happen. Food and land become more scarce. The supply of labor begins to exceed the demand. Wages decline while food prices increase. Peasants gravitate toward the larger cities and join unemployed workers as sources of protest and unrest. Elites, initially the primary beneficiaries of population growth, also begin to feel the effects. Their numbers are too great for a shrinking pool of resources to exploit. Intraelite conflict should also be expected. State makers are hardly immune to these trends. Bureaucracies, armies, and state revenues expand with population growth. Ultimately, though, states also begin to feel the pinch and may turn to more coercive approaches to revenue extraction. Even so, state breakdowns become more probable as their ecological environment turns more hostile.
Only a decline in population growth can turn things around. Thus, the basic processes of preindustrial demographic, political, economic, and social life are characterized by a four-phased cycle: expansion and growth, stagflation and slowing growth, crisis and decline, and depression. The first two phases are integrative and the last two are disintegrative in effect. This is the secular cycle referred to in the book's title and presumably applicable to historical time up to the era of industrialization or, alternatively, most of recorded (and unrecorded) history.
Peter Turchin and Sergey A. Nefedov improve on the original Goldstone argument in several ways. They expand the scope of the theory to encompass explicitly some 25 processes, ranging from population dynamics to trade. For political scientists, in particular, the 25 processes include elite dynamics, state strength and collective solidarity, sociopolitical instability, taxes, state finances, state policy, and ideology. They expand the historical scope of the theory. Whereas Goldstone looked at early modern Eurasia, Turchin and Nefedov compare and contrast medieval and early modern England, France, and Muscovy/Russia with ancient Rome. The longer historical scope encourages the authors to be more creative in finding appropriate evidence and proxy indicators, such as coin hoards and average heights. Not only do they find support for various interpretations of historical periods, but they also suggest new ways of looking at peaceful and turbulent eras. Moreover, they put forward some new findings on such processes as the “fathers-and-sons” generational dynamic, which entails a 50-year periodicity in discontinuous internal conflict, with one generation rejecting some aspects of the preceding generation's behavior.
There is not much to complain about in this impressive book. The prose is lean and manages to wend its way through a number of complicated histories without any unnecessary tangents. The emphasis is on testing the theory in a number of different but, as it turns out, similar cases. There is little question that the theory emphasizing the interaction between demographic cycles and sociopolitical instability finds ample support.
Rather than complain about what has been done, it is possible to suggest some things still to be accomplished. More cases need to be tackled. This book focuses on western Eurasia. Southern and eastern Eurasia need more attention (see, for instance, Victor Lieberman, Strange Parallels: Southeast Asia in Global Context, c. 860–1830, Vol. 2: Mainland Mirrors: Europe, Japan, China, South Asia, and the Islands, 2009). Non-Eurasian applications are also needed.
A second concern is the assumption that industrialization altered the nature of the workings of demographic cycles. Perhaps it did, but more probes of whether the theory has utility in an industrial era that remains more agrarian than industrial would be worthwhile. Turchin is already working in this area and appears to be finding that the theory may have more contemporary applicability than was originally thought.
A third area of investigation concerns Turchin and Nefedov's research design. They chose to look at each case on a one-by-one basis. Such a design permits a strong and consistent focus on a particular national or imperial trajectory. Yet one of the bonuses associated with Goldstone's early work is that it showed a number of places across Eurasia that were experiencing similar problems roughly at the same time. We need more broader examinations. We also need to turn Turchin and Nefedov's primarily domestic focus outward. They can explain internal warfare. Can these same processes be harnessed to account for external warfare as well? If they can help explain expanding armies, states, and trade, interstate warfare should not be beyond reach.
Finally, one of the topics that political scientists worry about is the creation of hierarchy in the world system at dyadic, regional, and global levels. If all states and empires experience similar processes, why is it that some become more powerful than others? Do some states beat the secular cycle, or is it that they take better advantage of it than other do? Since some of the more powerful states in history have not been the states with the largest populations, there is probably something other than population expansions and contractions going on that may be just as fundamental. I think it's a matter of technological innovation. Turchin has argued in earlier books that it is group solidarity. Sometimes disease plays a critical role.
Whatever the general case, there is ample room for further theoretical exploration and development. But there should be no doubt that this is an important book. Readers seeking historically sensitive but general explanations of behavior should appreciate the value-added of this research the most.
