Historical data indicate that periods of enhanced instability and internal warfare usually extend for many years, with the median length... 10–15 yea… - Peter Turchin

So the forecast seems to have been quite good. The question is "What was it based on?" It was not... a prophecy, it was a scientific prediction because there is a specific mechanism on which it was based. ...[T]he forecast was a scientific prediction in the sense that I wanted to stick my neck out [and] make an out-of-sample prediction to see whether the mechanisms that have been identified by our theory... actually are working in the way that we thought...

[T]he problem is that as we get greater numbers of these surplus elites... some of them turn into... counter-elites... the individuals who are willing to challenge... the reigning regime, and in history often... by violent means, and in fact this is happening in the United States... they're willing to break the rules of the game.

[T]he problem is... if the wealth pump is allowed to run long enough, eventually... the growing elite numbers and their consumption levels will overshoot the productive base, which is what the workers are producing.