Restrictions on medicaid funding of abortion: Effects on birth weight and pregnancy resolutions

Previous research suggests that restricting the availability of abortion reduces average birth weight. In this paper we use data from the National Longitudinal Survey of Youth to reexamine this question. Most previous studies have estimated the probability that a pregnancy is carried to term, and then used these estimates to calculate "selection corrections" that are included in models of birth weight. We focus instead on reduced form models of birth weight that are not affected by underreporting of abortion, and that do not involve strong identifying restrictions. We also explore the potential endogeneity of abortion laws by comparing jurisdictions with abortion restrictions to jurisdictions where restrictive laws have been passed but are enjoined by the courts. Our results provide little support for the hypothesis that restrictions reduce average birth weight. We also find some evidence that abortion restrictions are endogenous, and that estimated effects on birth weight may reflect unobserved characteristics of states.