Understanding the implications of the significant expansion in higher education over the latter half of the 20th century remains one of the central questions of research in stratification and inequality. Attaining a college degree is associated with numerous advantages ranging from higher earnings to improved health and wellbeing. As higher education continues to expand, however, there is the possibility of increasing variation in the benefits of a college degree. Sociologists have begun to examine variation in the returns to higher education for earnings, civic participation, and fertility. This dissertation contributes to this line of research by analyzing variation in the health-related benefits of a college degree. Chapters 2 and 3 assess variation in the effects of higher education on health outcomes (self-rated health, systolic blood pressure, body mass index, and smoking) and psychological wellbeing. Data are drawn from the National Longitudinal Study of Adolescent Health. The analyses rely on an innovative approach to detecting variation in the effects of a college degree that is based in the counterfactual framework and uses propensity score models to obtain estimates of various treatment effects. Chapter 4 examines the potential use of auxiliary variables in the handling of missing data. Missing data is an issue, particularly for the background variables, in the analyses in Chapters 2 and 3. Methodologists recommend using auxiliary variables, variables that are in some way related to missing data but not otherwise of substantive interest, when addressing missing data. This chapter provides guidelines for when auxiliary variables are more or less likely to be beneficial for reducing bias, which were used to inform the handling of missing data in the earlier chapters. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]