– 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.
2017 - State Affirmative Action Bans and STEM Degree Completions
The author utilized Integrated Postsecondary Education Data System (IPEDS). The author uses data on degree completions by major from 1998 to 2009. This paper only reports results for the first major to avoid the double counting of students. The mean share of minorities completing degrees is 12.7 percent in non-ban states and 24.5 percent in ban states. The STEM share of students is similar in non-ban (18.5 percent) and ban (17.8 percent) states.
The dependent variable in the primary specification is the natural logarithm of the number of degrees awarded to students in a particular race group. The independent policy variable is a binary variable indicating state-specific year-varying enforcement of affirmative action bans. The ban indicator is
interacted with indicators for highly selective colleges, moderately selective colleges, and nonselective colleges to separate effects by college selectivity.
In the primary specification, the author looks at the effects on degree completions five years after affirmative action is banned. This is the median time to graduation in the IPEDS graduation data (which is not major-specific, so otherwise not used in the analysis).
Two other dependent variables are considered: the minority share of students completing STEM degrees and the share of students completing STEM degrees relative to the total number of students completing degrees.