How resilient are our societies to internal and external shocks? - Peter Turchin

[T]he... forecast: “The next decade is likely to be a period of growing instability in the United States and western Europe” ...was not simply a projection of the current trend in social instability into the future. ...[T]he basis for this forecast was a quantitative model that took as inputs the major SD drivers for instability (immiseration, intraelite competition, and state (in)capacity) and translated them into the Political Stress Indicator (PSI)... strongly correlated with socio-political instability. The rising curve of the... PSI... suggests a growing future socio-political instability.

[M]y colleagues and I... focused on cycles of political integration and disintegration, particularly on state formation and state collapse.

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?