How Two-and Four-Year College Instructors with Different Contract Types Affect Students’ Academic and Labor Market Outcomes

Di Xu

Based on a novel dataset that links college administrative information with earnings records from a state college system for almost 80,000 students enrolled at either two-year or four-year colleges, this project will relate the proportion of course credits taken with different types of instructors — non-tenure track adjuncts hired through temporary appointments, non-tenure track instructors hired with long-term contract, and tenure-track/tenured faculty — during a student’s initial semester in college to her academic and labor market outcomes. To minimize bias from student sorting by instructors, I will use a course-set fixed effect model that compares between students who take exactly the same set of courses during their first semester of college enrollment; I will further augment the model by combining it with an instrumental variable approach which exploits term-by-term fluctuations in faculty composition in each department, therefore controlling for both between- and within- course sorting. Finally, based on the rich information on instructors’ demographic characteristics and multi-year employment records in this state, I will explore the extent to which instructor effectiveness can be explained by observable instructor demographic characteristics and employment features. This study will provide the first quasi-experimental evidence regarding the impact of different types of college instructors on student labor market outcomes, as well as a comprehensive exploration of possible mechanisms that may explain such impacts.

About Di Xu

Di Xu is an assistant professor of educational policy and social context at the University of California, Irvine. She is also a research fellow with the Community College Research Center at Teachers College, Columbia University and a visiting fellow at the American Enterprise Institute. Her research uses experimental and quasi-experimental designs to examine the impacts of postsecondary educational programs and policies aimed at improving college students’ educational outcomes, with a particular focus on students from low-income and underrepresented groups. Her work has been published in the American Educational Research Journal, Community College Review, Educational Evaluation and Policy Analysis, Educational Researcher, Economics of Education Review, Journal of Higher Education, Journal of Human Resources, Journal of Research on Educational Effectiveness, and the invitation-only journal New Directions for Community Colleges, among others; the findings form her studies have also been widely cited in various news outlets including the New York Times, The Atlantic, the Chronicle of Higher Education, Inside Higher Ed, Diverse Issues in Higher Education, and other outlets. Di has a Ph.D. in economics and education from Teachers College, Columbia University.