I went back to Bowles and Gintis to compare their results to those of Greg Clark that I posted about recently. The largest correlation reported by Bowles and Gintis for intergenerational earnings is 0.65, obtained when fathers’ and sons’ earnings are averaged over multiyear periods, whereas Clark finds a (roughly) 0.7 — 0.8 correlation between parental and children’s social and economic status. Clark was studying the past 200 years, using rare surnames, whereas Bowles and Gintis concentrated on the modern era. Even the lower value of 0.42 (more typical of results cited by Bowles and Gintis) implies some persistent stratification, as shown in the figure below.