Is the Opportunity Cost Model Overstated? The Role of Biological and Social Constraints in Fertility Intentions and Outcomes

Hans Johnson, Public Policy Institute of California (PPIC)
Laura Hill, Public Policy Institute of California (PPIC)
Joseph M. Hayes, Public Policy Institute of California (PPIC)

Little empirical research has focused on identifying the role of biological and social constraints versus opportunity costs in low fertility among highly educated women. Social constraints might prevent highly educated women from having children while unmarried, and biological constraints could play a role as childbearing is shifted to older and less fecund ages. In this paper, using panel datasets from the NSFH and NSFG, we quantify the extent to which low fertility rates among highly educated U.S. women are a consequence of opportunity costs versus social and biological constraints. We examine women’s stated fertility goals at an initial period, and compare these to their subsequent fertility outcomes and to their stated fertility goals after a number of years. Our preliminary findings suggest that the opportunity cost model, while still relevant, is overstated. Many highly educated women lower their fertility goals or do not achieve their desired fertility because of biological and social constraints.