Abstract
Using the American Community Survey data 2012-2013, I study married and cohabiting same-sex couples. I show that gay couples exhibit more specialization and less similarity than lesbian couples, while marriage makes gay and lesbian couples more alike than cohabiting couples, in terms of larger earnings differences for lesbians, and more positive sorting by education for gays. Education does not increase the odds of marriage among same-sex couples, contrary to heterosexual couples; lesbians are instead similar to heterosexual couples in their education being negatively associated to the number of children.