I estimate the impact of abortion legalization on spouses’ labor supplies to test whether legalization increased women’s household bargaining power, in a collective household behavior framework. Based on CPS data, I find that wives’ labor supply decreased and their husbands’ increased, which is consistent with the bargaining hypothesis. This contrasts with most studies of abortion and birth control technologies, which predict a labor supply effect only for women, and of opposite sign. Also consistent with the bargaining interpretation, I estimate no significant impact on anti-abortion religious couples or on those who regularly used contraceptives. PSID data yield supportive evidence. Copyright Springer Science+Business Media, LLC 2007Legalization of abortion, Household bargaining power, Labor supply, D1, J22,