[T]he problem is... if the wealth pump is allowed to run long enough, eventually... the growing elite numbers and their consumption levels will overs… - Peter Turchin

Let's look at ... wages adjusted for inflation. ...In the late 1970s there was a definite phase transition. Up to that point, for the previous two generations, the wages for both unskilled and manufacturing workers had been growing quite rapidly and almost linearly... [W]ages for manufacturing workers increased... fourfold... a quite remarkable achievement... [I]t was unprecedented in human history to see such a long-term sustained increase in general well-being. Then... the wages stagnated, or even declined. So what was the reason?

How resilient are our societies to internal and external shocks?

It became clear... through quantitative historical analysis that [throughout time] complex societies everywhere are affected by recurrent and, to a... degree, predictable waves of political instability, brought about by the same basic set of forces...