Essays on educational choices, peer effects, and diversity in higher education

Abstract

This dissertation studies how students' outcomes depend not only on who they are or what they choose individually, but also on the academic environments around them. The chapters focus on two settings: how students combine undergraduate majors, and how students are affected by the composition of their doctoral cohorts. Across these settings, the dissertation asks how academic breadth, peer composition, and diversity shape educational and labor-market outcomes.

Chapter 1, joint work with my advisor Dr. Valerie Bostwick, studies double majoring. The chapter asks whether having two undergraduate majors is associated with higher wages, and whether the answer depends on the relationship between the two fields. A second major may be valuable when it complements the first major, but it may be less valuable if it pulls students away from deeper specialization. Using ACS data, the chapter shows that the returns to double majoring differ by field combination and by gender.

Chapter 2 examines doctoral cohorts and focuses on changes in the share of international students within an entering cohort. It asks how doctoral outcomes change as the international-student share of a cohort increases. Specifically, the chapter studies whether a higher share of international peers is associated with students' persistence, time to degree, and degree completion, and whether these relationships differ across fields and cohort environments.

Chapter 3 also studies doctoral cohorts, but focuses on broader forms of diversity. It examines gender, racial/ethnic, and linguistic diversity within doctoral entering cohorts. The chapter asks whether these forms of diversity are related to doctoral students' progress and completion, and whether the relationships differ depending on the type of diversity and the initial composition of the cohort.

Together, the three chapters show that composition matters, but not in a simple one-directional way. A second major, an international peer group, or a diverse cohort can have different implications depending on the field, the type of composition, and the environment in which students are embedded. The dissertation therefore highlights the importance of looking beyond individual students and studying the academic contexts in which educational choices and outcomes take shape.