– Statewide affirmative action bans reduce minority STEM degree completions at US public four-year colleges. While there is no change in the total number of STEM degree completions, the number of minority STEM degree completions at highly selective colleges declines by nineteen percent, and the share of minority STEM degree completions declines by ten percent.
– The author does not observe convincing evidence of any increases in minority STEM degree completions at moderately selective colleges that would be consistent with minority students cascading down the college selectivity distribution and finding better matches after affirmative action bans.
– Affirmative action bans reduce the number of minority non-STEM degree completions by twenty percent at highly selective colleges. This is slightly larger than the effect on STEM degree completions, although the difference is not statistically significant.
– Overall, these findings suggest that student-college mismatch in STEM arising from race preferences in college admissions does not appear to be an overarching and pervasive phenomenon in the study sample, and affirmative action may actually be an effective policy for boosting minority representation in STEM in some circumstances.
– Affirmative action bans also increase the number of students of unknown race completing STEM degrees, which is consistent with an emerging literature that argues that minorities may no longer perceive an incentive to report their race after affirmative action is banned (Antman and Duncan, 2015).
– There is a clear reduction in the minority share of STEM degree completions at highly selective colleges four or five years after affirmative action is banned, while there is no effect at moderately selective or nonselective colleges.