College course grades are higher when students are assigned TAs of a similar race/ethnicity

Over the past 40 years, higher education institutions in the U.S. have experienced a dramatic shift in the racial composition of students enrolled in both undergraduate and graduate programs.    Using
administrative data from a large, diverse university in California this study identifies the extent to which the academic outcomes of undergraduates are affected by the race/ethnicity of their graduate
student teaching assistants (TAs).  To overcome selection issues in course taking, the study exploits the timing of TA assignments, which occur after students enroll in a course.

Results show a positive and significant increase in course grades when students are assigned TAs
of a similar race/ethnicity.  These effects are largest in classes where TAs are given advanced copies of exams and when exams had no multiple choice questions.

Assignment to similar race TAs positively affect both section and office hour attendance,
suggesting that TA-student match quality and role model effects are the primary drivers of the results.