2026 Theses Doctoral

Three Essays on the Economics of Higher Education

Libassi, Carmello J.

This dissertation comprises three essays on the economics of higher education, each examining socioeconomic disparities at a different stage of the postsecondary trajectory.

Chapter 1 uses a within-study design to benchmark recent regression discontinuity extrapolation methods against experimental estimates from the HAIL scholarship randomized controlled trial at the University of Michigan, providing guidance on the validity of these techniques for studying college access interventions.

Chapter 2 estimates the causal effect of Pell Grant generosity on re-enrollment and student loan borrowing using a difference-in-differences design with a simulated eligibility instrument applied to administrative aggregates for the universe of dependent first-year aid recipients in the United States; the effects vary substantially across credential level and institutional selectivity, with the largest enrollment responses concentrated where credit substitution is weakest.

Chapter 3 links administrative records from a large urban public college system with state unemployment insurance wage records to document that socioeconomic gaps in earnings five years after graduation are largely mediated by differences in students' first jobs, even conditional on rich measures of pre-college preparation and in-college performance.

Taken together, the essays characterize the magnitude and mechanisms of income-based gaps in college access, persistence, and post-college earnings, and identify policy levers and methodological tools for narrowing them.