763 [ Journal of Labor Economics, 2007, vol. 25, no. 4]  2007 by The University of Chicago. All rights reserved. 0734-306X/2007/2504-0004$10.00 Marriage, Specialization, and the Gender Division of Labor Matthew J. Baker, Hunter College, City University of New York Joyce P. Jacobsen, Wesleyan University We consider why the gender division of labor is so often enforced by custom and why customary gender divisions of labor generally involve both direction and prohibition. In our formal model, agents first learn skills and then enter the marriage market. We show that wasteful behavior may emerge due to strategic incentives in special- ization choice and human capital acquisition and that both problems may be mitigated through a customary gender division of labor. This division is not Pareto improving. Both the distributional effects and welfare gains of a customary gender division of labor decrease as opportunities for market exchange increase. I. Introduction Gary Becker’s (1991) work(s) on the economics of marriage began the study of marriage and its relationship to the gender division of labor and human capital acquisition. Becker’s theory began with the observation that spouses could specialize in specific tasks and then engage in trade at Early versions of this article were presented in seminars at the U.S. Naval Academy, Hunter College, and Wesleyan University and at the 2003 International Association for Feminist Economics session at the Allied Social Science Associ- ations meeting entitled “Feminism Meets New Institutionalism.” We would like to thank Nancy Folbre, Oded Galor, Victor Li, Padma Rao Sahib, Gil Skillman, and session participants for valuable comments and suggestions. Contact the cor- responding author, Joyce Jacobsen, at jjacobsen@wesleyan.edu.