Does the gender composition in couples matter for the division of labor after childbirth?

In this paper I compare the effect of entering parenthood on the spousal income gaps in lesbian and heterosexual couples using Swedish population wide register data. Comparing couples with similar pre-childbirth income gaps, a difference-in-differences strategy is used to estimate the impact of the gender composition of the couple on the spousal income gap after childbirth. The results indicate that the gender composition of the couple does matter for the division of labor after having children. Five years after childbirth the income gap is smaller in lesbian than in heterosexual couples also when comparing couples with the same pre-parenthood income gap. Heterosexual couples’ division of labor seems to be influenced by traditional gender norms, regardless of their pre-childbirth income gap. In lesbian couples the partners’ relative earnings before parenthood and a principle about fairness may be more important, as well as the partners’ preferences for giving birth as the birth giving partner typically spends more time on parental leave.