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Working Paper

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This research has been supported by the Russell Sage Foundation Award (83-16-13).


The growing economic similarity of spouses has contributed to rising income inequality across households. Explanations have typically centered on assortative mating, but recent work has argued that changes in women’s employment and spouses’ division of paid work have played a more important role. Using three U.S. nationally representative surveys, we examine the role of parenthood in spouses’ earnings correlations between 1968-2015, asking to what extent: (1) changes in spouses’ earnings correlations are due to changes before versus after first birth; (2) changes in spouses’ pre-birth correlations are due to changes in assortative mating versus shifting roles in marriage, and (3) observed trends have been driven by changes in women’s employment. We find that parenthood is an increasingly important mechanism, with growing economic similarity after 1990 due almost entirely to changes following parenthood. Prior to 1990, changes in economic similarity before parenthood played a larger role, although these were not driven by assortative mating at the time of marriage. Instead, we show that increases in women’s employment within marriage explain the rise of both pre- and post-birth similarity. An assessment of the aggregate-level implications points to the growing significance of earnings similarity after parenthood for rising income inequality across families.


income inequality, parenthood, women’s employment, assortative mating, economic homogamy



Date Posted: 18 February 2020