The new issue of Cliodynamics: The Journal of Quantitative History and Cultural Evolution celebrates the Demographic Structural Theory (DST), one of the great success stories in Cliodynamics. DST was conceived by Jack Goldstone when he was a graduate student at Harvard during the late 1970s. Jack started as a Physics major at Caltech, but then decided to switch to sociology. As he writes in his retrospective that introduces the special issue, “I wanted to see if I could use mathematical models to explain when revolutions would occur.” His approach was that of a natural scientist, and he set out on a comparative study of revolutions that broke out in different parts of the world and at different times. He wanted to understand general principles:
It was obvious that any model that explained revolutions would have to include multiple components at different levels of society, and comprehend state vulnerability, intra-elite conflicts, and popular grievances and mobilization. But what could trigger all of these varied factors to come together at a certain time in a revolutionary conjuncture? If they all moved randomly and independently of one another, then the incidence of revolutions would also be random, arising only when peaks in these varied factors happened to converge in a given country at a given time. Of course, it was possible that revolutions were just random conjunctures of state crisis, elite conflicts, and popular uprisings, perhaps brought on by a particularly foolish ruler, or a particularly costly war, or the rise of an unusually potent heterodoxy or movement.
Revolution of 1848 Source
But his comparative study of revolutions quickly convinced him that this couldn’t be the case—there were just too many common patterns:
So it seemed that some broadly synchronous force was at work. But what hidden force could be strong enough to simultaneously drive state crises, elite divisions, and multiple kinds of popular grievances across many different countries and regions at certain times but not others?
I won’t go into details (you should read Jack’s excellent essay, which is in open access as everything in Cliodynamics), but it turned out that the “decoder ring” was demography. And this insight has withstood the test of time. Our “sample set” of historical societies that went into political crisis and state breakdown has expanded dramatically, and in every case we see the same general principles operating.
Unfortunately, the path to where we are now was not a straight one. In the essay Jack describes the “underwhelming” response both to his Ph.D. thesis on the English Revolution and his 1991 book Revolution and Rebellion in the Early Modern World (which we celebrate in the special issue). Although he expanded his empirical scope to include not only European Revolutions, but also those elsewhere in the early modern Eurasia (China, Ottoman Empire), historians and social scientists largely ignored it.
When I think about that early indifference and outright rejection of DST, I realize how lucky I was that I embarked on the study of cliodynamics 20 years after Jack (and only after I had a tenured position). The 1980s and 1990s were one of those cyclic downturns during which the social mood swang against general theories. Those two decades saw the decline of cliometrics and “processual” archaeology, the “cultural turn” in history, and the reign of Post-Modernism in many social science departments.
We are still a long way from broad acceptance of DST, both among scholars and (even farther away) policy makers. But the title of this blog post is not an exaggeration. DST is a mature scientific theory because, first, we have greatly refined its mathematical apparatus. In addition to Jack’s Political Stress Indicator approach, which is a quantitative “social pressure gauge,” we have dynamical models of feedback loops that bring about secular cycles of alternating integrative/disintegrative periods, and micro-level models of violence outbreaks. The missing link is the “micro” – “macro” connection (see our article in the issue).
Second, and even more important, we now have an order of magnitude better empirical base for our theories. There are between 20 and 30 well-studied case studies, thanks to the work of Jack himself, Russian scholars like Sergey Nefedov and Andrey Korotayev, myself, and others. Furthermore, we have deepened our empirical understanding of these cases thanks to the recently accumulated historical scholarship. We started applying the theory to contemporary societies, for which data are much more available.
And this leads me to another thought. Jack’s 1991 book was not only ahead of its times, he was remarkably prescient about our own society. As he wrote (now 27 years ago): “It is quite astonishing the degree to which the United States today is, in respect of its elites’ attitudes and state finances, following the path that led early modern states to crisis.”
When 10 years ago I decided to take a look, I was even more appalled, because by that point the writing was literally on the wall. Today (following the 2016 US presidential election and the aftermath) it seems to be dawning on all of us (although most people have no idea about the deep structural drivers of our current age of discord).
I don’t want to quote too much of Jack’s article, because you should read it yourself, but I can’t resist one more quote about a concept that I introduced in Ages of Discord. A relative wage is simply the wage divided by GDP per capita. It tells us about the share of national output that goes to workers. Relative wages reached a peak during the late 1960s, and have been declining ever since. Why is this important?
A high relative wage thus promotes social stability in multiple ways: workers feel they are getting a fair share of economic growth, while growth of inequality due to rising elite incomes is averted. In addition, if elites cannot grow their incomes at the expense of workers, but only by increasing output as a whole, they are motivated to raise and reward worker productivity and invest in public goods that raise overall output.
This is an insight that our governing classes should really take to heart. This week in Davos the global elites were (now traditionally) lamenting the rising inequality, yet the policies they have been implementing in one country after another result in depressing relative wages (see, for example, an unusually harsh post from Branco Milanovic on this). It reminds me of someone, but I can’t quite put my finger on it…
Vigée-Lebrun (1778) Marie Antoinette in Court Dress Source