Peter Turchin is the founder of a new kind of scientific history named “cliodynamics”. He and his team have collected a vast database of historical data: on populations, economic statistics, epidemics, laws, and heath data. It covers most of the world over an extended time period. From this he derives testable scientific theories about history. The focus of this book is his theory of “elite overproduction and popular immiseration”, which says that throughout history there is a tendency for elites to extract ever more surplus from the working class, which becomes immiserated in the process, while the elite expands until there too many “elite candidates” for the elite roles on offer. The frustrated aspirants then mobilise the immiserated and ripe-for-revolution masses to destabilise the state and cause a collapse. This slims down the size of the elite, and often the population as a whole and allows the cycle to repeat itself. In pre-industrial societies the cycle is Malthusian, with over population leading to famines and epidemics that cull the numbers, but in the modern era he says the mechanism is the strength of the “wealth pump”, and how efficiently it pumps wealth to the elite. The book focuses on the USA, which he thinks is now due a revolution or civil war. Prescient with Trump returning to the Whitehouse. Do I buy it? He makes a very persuasive case, especially for pre-industrial societies, but I’m not so convinced about his diagnosis of the US. His model fails to account for business innovation and the overall growth of the economic pie. He only cares how it’s cut. While he admires Denmark and Austria, they are hardly engines of world economic growth like the US. It’s all a bit too Marxist for me. I do think the idea of “elite overproduction” is a useful one though. Who knows whether his predictions about the future of the US turn out to be true. I rather hope not because they are quite apocalyptic!