Department or Program


Primary Wellesley Thesis Advisor

Patrick McEwan


Does the gender of a student’s initial STEM instructor have any causal effect on major choice? Using a panel of student-by-course data from Wellesley College, I measure the effects of female STEM instructors on female student major choice. The main threats to internal validity are non-random student selection in or out of class sections based on observable or unobservable characteristics, along with simultaneity. To mitigate these threats, I employ an instrumental variable that uses the exogenous variation induced by random patterns of faculty hires and leaves within a given department and semester. My analyses find that exposure to female STEM professors significantly increases a female student’s probability of majoring in a STEM department. Female STEM professors increase the likelihood of a student major by 5 to 6 percentage points, which is about a 25% increase from the major declaration rate with male STEM professors. These positive results are especially pronounced for students with high SAT Math scores, where female professors increased the likelihood of majoring in STEM by 11 to 13 percentage points, a 40%-45% increase. I also observe significant negative female professor effects in the Humanities and Non-Economics Social Sciences. These results are consistent with the theories and empirical findings detailed in past literature, that exposure to female professors in traditionally male-dominated fields (i.e. STEM) increase female majors in those areas.

Available for download on Wednesday, April 26, 2023