I wonder how much these stats are influenced by the changing age differences between partners. It used to be typical for men to be older than their wives and very shocking/bizarre for a woman to much older than her husband. It seems to me that the older partner has had more time to get an education and build a career, so even if you were to compare their earnings and education at the same age and find it was terribly different, the older partner may still make more money currently. Since it seems like it is becoming increasingly common/acceptable for spouse's to be the same age or for the wife to be older, I wonder how much influence (if any) that has on these figures.