This paper investigates an unanticipated consequence of rising income inequality, namely
changes in patterns of educational assortative mating. The association between spouses’
educational attainments has important implications for economic and social inequalities
among families and households. Over the past 40 years in the U.S., the resemblance of
husbands’ and wives’ educational attainments has increased markedly. For example, the
proportion of couples in which spouses share the same broad education category
increased by approximately 20 percent and the odds of educational homogamy increased
by about 25 percent during this period (Schwartz and Mare 2005). Although rising
inequality among households may be a consequence of increasing spousal resemblance
on educational attainment, income inequality among individuals may itself be a cause of
trends in educational assortative mating. Rising earnings inequality has resulted in
increasing returns to education and thus wider economic and social gaps between
education groups. These widening gaps may account for couples’ increasing tendency to
marry along educational lines. In this paper, we evaluate this argument by analyzing
Decennial Census and Current Population Survey data from 1940 to 2003 on the
educational resemblance of spouses and the income distributions of men and women
within education groups. We also consider several other factors that may affect
assortative mating trends, including increases in the relative earnings of women in the
immigrant population and changes in the timing of schooling and marriage. Trends in the
earnings gaps between educational groups and reduced gender inequality in the
workforce appear to account for most of the change in several key measures of spousal
resemblance in educational attainment since the early 1970s. From 1940 to the early
1970s, changes in educational assortative mating may be mainly the result of changes in
the timing of school leaving and entry into marriage.