Earnings Inequality and the Changing Association between Spouses' Earnings

Increases in the association between spouses' earnings have the potential to increase inequality as marriages increasingly consist of two high-earning or two low-earning partners. This article uses log-linear models and data from the March Current Population Survey to describe trends in the association between spouses' earnings and estimate their contribution to growing earnings inequality among married couples from 1967 to 2005. The results indicate that increases in earnings inequality would have been about 25%-30% lower than observed in the absence of changes in the association, depending on the inequality measure used. Three components of these changes and how they vary across the earnings distribution are explored.