The Son Also Rises, Chapters 8-12

 The first few chapters in this section look at India (specifically the state of West Bengal), China, Taiwan, Korea, Japan, and Chile. The specific numbers that he finds when looking at England and certain US demographics don't always hold up; I think he's a bit too wedded to the idea that he's found a universal law of class mobility/persistence. Shocks from big events do matter, to some extent. However, a few patterns do hold:

1) If you look at the persistence of families in elite tiers of society, as opposed to intergenerational correlations of income, you see very slow regression to the mean. Income is just a proxy for status, and is imperfectly correlated 

2) Social reforms don't have nearly the effect that reformers were hoping for. Families that know how to navigate society still do fine, for a while at least. This should be deeply dismaying for social reformers who think that we can remedy inequality in the classroom. We can probably have some effects on the margin, but not only are our students not blank slates, they aren't even erasable slates, and large portions of the slate are off-limits to us.

3) When he's able to look at long time scales there are strong signs of Markovian dynamics in many cases, and these Markovian dynamics are as true for upward regression to the mean as downward regression to the mean. While the pace would be dispiriting to social reformers, the fact that each generation has an element of reset should be encouraging for them.

Chapter 12 is the most interesting chapter for me, as a physicist, because he looks at time reversal. He shows that if, instead of starting with people who were high-status centuries ago in England, you start with people who were high-status more recently, and then look into the past, going backwards in time they also regress to the mean. This is consistent with the idea that microscopic dynamics of Brownian motion look the same in either time direction, even if macroscopic dynamics look very different. This is just such a cool chapter that I would seriously consider discussing it the next time that I teach statistical physics. Seriously.

As to the persistence of the upper classes after putative egalitarian reforms, let me just note that upper-class jerks always write the best Diversity and Inclusion Statements. I don't if it's always been that way, or if they learned it after the French Revolution, but the offspring of the upper classes seem to be absolutely amazing at explaining that they're One Of The Good Ones and it's those other assholes who need to face a guillotine.