Explaining Differences in Assortative Matching between Same-Sex and Opposite-Sex Couples

Christine R. Schwartz, University of Wisconsin at Madison
Nikki L. Graf, University of Wisconsin at Madison

Same-sex couples tend to be less homogamous than opposite-sex couples on a variety of characteristics, including age, education, and race/ethnicity. However, no study has systematically investigated the possible sources of these differences. We use data from the 1990 and 2000 censuses to investigate several hypotheses. One possibility is that same-sex couples are less homogamous than opposite-sex couples because there are fewer potential partners from which to choose. Another possibility is that if individuals choose homogamous relationships to ensure that their characteristics are passed on to their children, then differences in expected fertility may explain the lower odds of homogamy among same-sex couples. Finally, same-sex couples may be less homogamous than opposite-sex couples because they are more geographically mobile and thus subject to lower levels of parental influence over their choice of mates.