New evidence on the relationship between substance use and adolescent sexual behavior.

Policymakers and the public have a clear interest in encouraging teens to delay becoming sexually active or, if they are sexually active, to use birth control. Many researchers have argued that reducing substance use among teens will accomplish both of these goals, yet work in this area has failed to control for unobservables that are potentially correlated with substance use and sexual behavior. Using a variety of estimation techniques and data from National Longitudinal Study of Adolescent Health, we estimate the effects of marijuana and alcohol use on two outcomes: the probability of being sexually active, and the probability of having sex without contraception. Our results highlight the importance of controlling for unobservables and indicate that the link between substance use and sexual behavior is much weaker than previously suggested.

Enforcing divorce settlements: evidence from child support compliance and award modifications.

This paper uses an implicit contracting framework to understand the dynamic nature of divorce settlements and to analyze the determinants of noncompliance with child support awards. In addition to the standard economic variables that affect the noncustodial parent's (NCP's) ability to pay child support, our approach focuses on factors that may affect the NCP's desire to pay, such as the ongoing relationship between the two parents and between the NCP and the children. We also examine the "state-contingent" nature of child support payments and explore the factors that lead to modifications in child support agreements. Using a longitudinal data set collected by the Stanford Child Custody Project, the empirical analysis provides documentation that compliance by noncustodial fathers can vary substantially from month to month. In addition, we find that even within a short period after divorce, a substantial minority of parents agree to make informal modifications to their divorce settlement in response to changes in economic circumstances and in custodial arrangements.

The impact of child support on cognitive outcomes of young children.

We use the National Longitudinal Survey of Youth-Child data to address three questions. First, does the receipt of child support have beneficial effects for children with absent fathers apart from increasing income? Second, do the effects of child support differ when child-support awards and payments are made cooperatively as opposed to being court ordered? Third, are any positive effects of child support solely a product of unmeasured differences among fathers and families? Controlling for the socioeconomic characteristics of the child and family, we find some evidence that receipt of child support has a positive impact on children's cognitive test scores over and above its contribution to total income. However, the effects vary by test, by race, and by reason for father's absence. Our results also indicate that the distinction between cooperative and noncooperative awards is important. Finally, our instrumental variables estimates show that the effects of child support persist after we control for unobserved characteristics of fathers and families.