Freddie deBoer in Persuasion:
The concept of “elite overproduction” has attracted a lot of attention in the past several years, and it’s not hard to see why. Most associated with Peter Turchin, a researcher who has attempted to develop models that describe and predict the flow of history, elite overproduction refers to periods during which societies generate more members of elite classes than the society can grant elite privileges. Turchin argues that these periods often produce social unrest, as the resentful elites jostle for the advantages to which they believe they’re entitled.
Consider societies in which aristocrats enjoy feudal privileges over land and are afforded influence in government. These sorts of dynastic privileges have been common in world history. Now imagine that over time, the number of people in this class has grown; more and more children of aristocrats means there are more and more people who hold aristocratic status. This creates a math problem: there’s only so much land to divide up and only so many people that can meaningfully guide government.
More here.