Using data from the NLSY79, we structurally estimate a dynamic model of the life cycle decisions of young women. The women make joint and sequential decisions about school attendance, work, marriage, fertility and welfare participation. We use the model to perform a set of counterfactual simulations designed to shed light on three questions: (1) How much of observed minority-majority differences in behavior can be attributed to differences in labor market opportunities, marriage market opportunities, and preference heterogeneity? (2) How does the welfare system interact with these factors to augment those differences? (3) How can new cohorts that grow up under the new welfare system (TANF) be expected to behave compared to older cohorts?