Nevertheless She Persisted? Gender Peer Effects in Doctoral STEM Programs

Abstract

We study the effects of peer gender composition in STEM doctoral programs on persistence and degree completion. Leveraging unique new data and quasi-random variation in gender composition across cohorts within programs, we show that women entering cohorts with no female peers are 11.7pp less likely to graduate within 6 years than their male counterparts. A 1 sd increase in the percentage of female students differentially increases women's probability of on-time graduation by 4.4pp. These gender peer effects function primarily through changes in the probability of dropping out in the first year of a Ph.D. program.

Figure 1:. Trends in Cohort Gender Composition By Field

Each panel represents a STEM field and each line within a panel represents a unique doctoral program in the main estimation sample. The x-axis measures incoming cohorts over time and the y-axis measures the share of each incoming cohort that is female.

Figure 2:. Correlation Between Cohort Gender Composition and Covariates (Demeaned)

In each panel above, a point represents a cohort within a program. The x-axis measures the percent of each cohort that is female minus the average percent female in the program over all years of the data. The y-axis in each panel represent a different covariate, also demeaned at the program level. Proceeding clockwise from the top-left, these variables are: cohort size, age, an indicator for white race, and an indicator for foreign-born. Each panel includes the estimated slope coefficient and corresponding p-value from a simple linear regression of the demeaned y-variable on the demeaned cohort gender composition.

Figure 3:. Dropout and Graduation Rates by Year of Enrollment

The x-axis measures the program-year. The y-axis indicates the fraction of students in the main estimation sample belonging to each category (dropped out, graduated, or still enrolled) measured at the end of each program-year.

Figure 4:. Distribution of First Term Grades by Gender

The left panel shows the first term GPA distributions for all students in cohorts where the fraction female is below the average for that program (“highly-male” cohorts). The right panel includes all students in cohorts where the gender composition is above the average for that program (“highly-female” cohorts).