Many historical processes exhibit recurrent patterns of change. Century-long periods of population expansion come before long periods of stagnation and decline; the dynamics of prices mirror population oscillations; and states go through strong expansionist phases followed by periods of state failure, endemic sociopolitical instability, and territorial loss.
Turchin argues that the key to the formation of an empire is a society’s capacity for collective action. He demonstrates that high levels of cooperation are found where people have to band together to fight off a common enemy, and that this kind of cooperation led to the formation of the Roman and Russian empires, and the United States. But as empires grow, the rich get richer and the poor get poorer, conflict replaces cooperation, and dissolution inevitably follows.
How groups manage to escape the prisoners’ dilemma and cooperate is a central question of evolutionary biology. Turchin argues that the social construction of “other” along meta-ethnic frontiers (which are often defined in terms of factors other than ethnicity, in particular religion), is necessary to enable group cooperation which allows empire building. This is why empires almost invariably arise along frontiers. A ruling class with a high potential for collective action will expand while financing its wars by taxing the peasants. In the early days of the empire, the elite are relatively austere warriors, and low population densities allow peasants to produce a significant surplus, so elite requirements do not overburden peasant production. As population densities increase, the surplus produced per peasant decreases because each has less land, but at the same time rents charged by the elites increase as land becomes scare. Peasants become poorer, though the elite continue to do well. Wealth inequality increases, and eventually the peasant base cannot sustain the high expectations of the growing elite population. Consequently, some of the elite class find themselves without land to sustain their lifestyle, while others become extremely wealthy due to control of scarce resources. This gives rise to intra-elite conflict. Social cohesion declines due to increasing inequality, both between elite and peasant classes and within the elite. The result is that peasants who are desperate and weakened by poverty are drawn into elite infighting. A combination of civil war, famine and plague reduces the population of the weakened state. The population decline ultimately leads to lower food prices and increased wages for the poor, but the loss of social cohesion is not so easily reversed. The recovery is thus impeded by continued infighting, and sometimes an outside group with higher asabiya takes over before another expansion phrase is triggered.
Peter Turchin and Sergey Nefedov explore the dynamics and causal connections between such demographic, economic, and political variables in agrarian societies and offer detailed explanations for these long-term oscillations–what the authors call secular cycles.
Secular Cycles elaborates and expands upon the demographic-structural theory first advanced by Jack Goldstone, which provides an explanation of long-term oscillations. This book tests that theory’s specific and quantitative predictions by tracing the dynamics of population numbers, prices and real wages, elite numbers and incomes, state finances, and sociopolitical instability. Turchin and Nefedov study societies in England, France, and Russia during the medieval and early modern periods, and look back at the Roman Republic and Empire. Incorporating theoretical and quantitative history, the authors examine a specific model of historical change and, more generally, investigate the utility of the dynamical systems approach in historical applications.
Turchin has three books developing his approach. “War and Peace and War: The Life Cycles of Imperial Nations” is the popular introduction. It describes the approach without any math or equations, and applies it to a range of historical empires. This is the place to start for a general introduction, particularly if you are not mathematically inclined. However, it is not formally rigorous and will not convince you if you are sceptical. “Secular Cycles” (with Sergey Nefedov) supports the theory with quantitative empirical data. It applies the model to two cycles in each of England, France, Rome and Russia. This is the book to read if you are comfortable with numbers and need to be convinced by empirical evidence.
“Historical Dynamics: Why States Rise and Fall” provides the theoretical framework, discussing, for example, why an explanation of cyclical dynamics requires a feedback loop. It is quite mathematical, and while you don’t have to work your way through all the equations, you should be comfortable with mathematical models generally. Turchin’s model was inspired by Jack A Goldstone, “Revolution and Rebellion in the Early Modern World.” This is also an excellent book. It is written in a more traditional historical style; the model is informal, rather than formal, and the argument is supported by historical analysis of particular revolutions, rather than by quantitative data. In these respects it is similar to “War and Peace and War,” though it is substantially longer. If you are looking for an extended analysis in a more traditional style of social history, this a great book.
Tainter first elegantly disposes of the usual theories of social decline (disappearance of natural resources, invasions of barbarians, etc). He then lays out his theory of decline: as societies become more complex, the costs of meeting new challenges increase, until there comes a point where extra resources devoted to meeting new challenges produce diminihsing and then negative returns. At this point, societies become less complex (they collapse into smaller societies). For Tainter, social problems are always (ultimately) a problem of recruiting enough energy to “fuel” the increasing social complexity which is necessary to solve ever-newer problems.
Complexity, writes Tainter, describes a variety of characteristics in a number of societies. Some aspects of complexity include many differentiated social roles, a large class of administrators not involved in the production of primary resources, energy devoted to different kinds of communication, centralized government, etc. Societies become more complex in order to solve problems. Complexity, for Tainter, is quantifiable. Where, for example, the Cherokee natives of the U.S. had about 5,000 cultural artifacts (things ranging from recipes to tools to tents) which were integral to their culture, the Allied troops landing on the Normandy coast in 1944 had about 40,000.
Herein, however, lies the rub. Since, as Tainter writes, the “number of challenges with which the Universe can confront a society is, for practical purposes, infinite,” complex societies need to keep on increasing their level of complexity in order to survive new challenges. Tainter’s thesis is that these “investments in aditional complexity” produce fewer and fewer returns with time, until eventually society cannot muster enough energy to fuel complexity. At this point, society collapses.
Consider this example: A simple hunter-gatherer society with limited agriculture (i.e. garden plots) is faced with a problem, such as a seasonal drop in food production (or an invasion from its neighbours who have the same problem and are coming over for food). The bottom line is, this society faces an energy shortage. This society could respond to the food crisis by either voluntarily declining in numbers (die-off, and unlikely) or by increasing production. Most societies choose the latter. In order to increase production, this society will need to either expand territorially (invade somebody else)or increase agricultural production . In either case, this investment can pay off substantially in either increased access to already-produced food or increased food production.
But the hunter-gatheres of the above example incur costs as they try to solve their food-shortage problem. If they conquer their neighbours, they have to garrison those territories, thus raising the cost of government. If they start agriculture on a larger or more intense scale in their own territories, they have to create a new class of citizens to man the farms, distribute and store the grain, and guard it from animals and invaders. In either case, the increases in access to energy (food) are offset somewhat by the increased cost of social complexity.
But, as the society gets MORE complex to confront newer challenges, the returns on these increases in complexity diminish. Eventually, the costs of maintaining garrisons (as the Romans found) is so high that both home and occupied populations revolt, and welcome the invaders with their simpler way of life and their lower taxes. Or, agricultural challenges (a massive drought, or degradation of soils) are so great that the society cannot muster the energy reserves to deal with them.
Tainter’s book examines the Mayan, Chacoan and Roman collapses in terms of his theory of diminishing marginal returns on investments in complexity. This is the fascinating part of the book; the disturbing sections are Chapter Four and the final chapter. In Chapter 4, Tainter musters a massive array of statistics that show that modern society has been facing diminishing returns on investments in complexity. There is a very simple reason for this: we solve the easiest problems first. Take oil, for example. In 1950, spending the energy equivalent of one barrel of oil in searching for more oil yielded 100 barrels in discovered oil. In 2004, the world’s five largest energy companies found less oil energy than they expended in looking for that energy. The per-dollar return on R&D investment has dropped for fifty years. In education, additional investments in programs, technology etc. no longer produce increases in outcomes. In short, industrial society is looking at steadily fewer returns on its investments in both non-human and human capital.
When a new challenge comes, Tainter argues, society will eventually be unable to muster the necessary resources to deal with the crisis, and will revert– in a painful and unhappy way– to a much simpler way of life.
In his final chapter, Tainter describes the modern world’s “arms race of complexity” and makes some uncomfortable suggestions about our own future. (…). In an age where, for example, the U.S. invasion of Iraq has yielded net negative returns on investment even for the invaders (where’s that cheap oil?), and where additional investments in education and health care in industrialised countries make no significant increases in outcomes, the historical focus of Tainter’s work starts to become eerily prescient.
The scary thing about this deeply thoughtful and thoroughly researched book is its contention that the future, for all our knowledge and technology, might be an awful lot like the past.
WAR AND PEACE AND WAR: The Life Cycles of Imperial Nations by Peter Turchin
Experiments over the past decade or so have established that most individuals
aren’t the greedy, rational machines of neo-classical economics, but are often willing to cooperate
with others even when they clearly have nothing to gain by doing so. Some of the most
convincing efforts to explain such “irrational” tendencies point to a process of cultural group
selection that looks surprisingly like Turchin’s historical dynamics – competition between groups
of greater or lesser cooperative skills, with the more cooperative tending to win out.
But if high levels of internal cooperation lead to the rise of great empires, what leads to their
ultimate demise? Here Turchin suggests that another natural process comes into play. As an
empire grows rich, inequalities in wealth and power naturally emerge among its people.
Consequently, the very success of an empire sets up the conditions for its demise, through the
“corrosive effect that glaring inequality has on the willingness of people to cooperate”.
Turchin also illustrates this point with several historical examples, including the abrupt decay of
France in the 14th century, following glory in the 13th, and the fall of Rome. It would be
interesting to know what he makes of today’s America, and the fallout after the disaster and
debacle of New Orleans. But Turchin goes beyond mere examples.
He also argues that the emergence of such inequality ultimately has less to do
with people than with simple mathematics. A key discovery of so-called “complexity science”,
and the physics of systems that are out of equilibrium, is that growth often leads to a “rich get
richer” phenomenon, which naturally generates dramatic differences between distinct parts of a
system. This is true in systems ranging from the web – where a small fraction of sites account for
a large fraction of all hypertext links – to crystals growing in solution. In the context of
economics, rich-get-richer phenomena have been shown to cause a few business firms to become
far larger than all the others, and a few people to become incredibly wealthy. Inequalities emerge
inexorably, and for fundamental reasons.