The Effect of Class Size on Grades and Course Evaluations: Evidence from Multi-section Courses

Using rich administrative data from a small Dutch liberal arts college, I study how the number of students enrolled in a course affects student grades and course evaluations. To identify the causal effect I exploit variation in class size across parallel sections of the same course taught by the same instructor in the same semester. I show that class size has a stronger negative effect on student grades in mandatory courses compared to electives. I show similar results for various components of student course evaluations: perceived overall course quality, perceived amount learned, student participation and engagement. I interpret these findings to be consistent with class size affecting educational outcomes through student engagement.