Quite a number of people, here and on Twitter, asked me about how I came up with my forecast for 2020. Here’s the story. By the early 2000s I had already delved into structural-demographic theory and its implications for historical societies. These results went into Historical D

America is burning. Dozens of cities across the United States remain under curfews at a level not seen since riots following the 1968 assassination of Martin Luther King Jr. Most commentary is focusing on the immediate causes of this wave of violence that has already continued for six

After I published my last post on Coronavirus and Our Age of Discord, I’ve been looking through various lists of major epidemics in world history, both on resources such as Wikipedia and in academic articles. I know that there is a strong (although not perfect) association betwe

In recent days there was much discussion by historians on Twitter of the proper and improper uses of historical knowledge in testing social science theories. It was initially prompted by the publication of a Science article last week on historical Church exposure and global psychologi

Last week I visited Centre for Complex Systems Studies (CCSS) in Utrecht, where I gave a talk about my research results and plans for the Ages of Discord project. Several people on Twitter asked to see the slides, and so I am posting them on this blog. First, here’s an abstract

As the readers of this blog know, a big chunk of my research focuses on why complex societies go through cycles of alternating internally peaceful, or integrative, phases and turbulent, or disintegrative periods. In all past state-level societies, for which we have decent data, we fin

When I became interested in what eventually became Cliodynamics, initially I thought that I would just play with some mathematical models of historical processes, because I had read many times before that there is very little quantitative data in history. In fact, the opposite is true

Over the past weekend France has been rocked by “the worst urban riot in 50 years” (see reporting by Reuters, DW). Indeed the previous comparable outbreak of political violence in France was in May 1968, almost precisely 50 years ago. (As a reminder, I define “political violence” as i

The last installment in this series (first one here) adopts a more critical stance towards the article by McConnell et al., Lead pollution recorded in Greenland ice indicates European emissions tracked plagues, wars, and imperial expansion during antiquity. As I said in the second pos

When I started 20 years ago on the research direction that eventually became Cliodynamics, I thought that getting data to test theories about historical dynamics would be tough. Within a couple of years I realized that actually it’s not true. There is an enormous amount of quant