Assortative mating plus efficient wealth management in Norway, by Fagereng, Guiso & Pistaferri

 Here's a recent NBER working paper that sheds some further light on how assortative mating leads to divergence in family wealth. (Apparently the spouse who managed pre-marital wealth better has more weight in managing the family finances...). Among other things we learn that Norwegian data on income and wealth is really good.

Assortative Mating and Wealth Inequality  by Andreas Fagereng, Luigi Guiso & Luigi Pistaferri, NBER WORKING PAPER 29903 DOI 10.3386/w29903, April 2022

We use population data on capital income and wealth holdings for Norway to measure asset positions and wealth returns before individuals marry and after the household is formed. These data allow us to establish a number of novel facts. First, individuals sort on personal wealth rather than parents' wealth. Assortative mating on own wealth dominates, and in fact renders assortative mating on parental wealth statistically insignificant. Second, people match also on their personal returns to wealth and assortative mating on returns is as strong as that on wealth. Third, post-marriage returns on family wealth are largely explained by the return of the spouse with the highest pre-marriage return. This suggests that family wealth is largely managed by the spouse with the highest potential to grow it. This is particularly true for households at the top of the wealth distribution at marriage. We use a simple analytical example to illustrate how assortative mating on wealth and returns and wealth management task allocation between spouses affect wealth inequality.