1/ In November, California voters will decide whether to repeal Prop 209, which banned affirmative action at public universities.

I wrote about a new @zbleemer study that shows the ban harmed Black and Hispanic students, and didn't help others. https://www.nytimes.com/2020/08/21/upshot/00up-affirmative-action-california-study.html?smid=tw-share

2/ Proponents of Prop 209 like Ward Connerly said it would be *good* for minority students because of reputation, self-esteem, and the "mismatch hypothesis," which posits that they can't compete with more academically-qualified peers.

The study suggests Ward Connerly was wrong.

3/ Instead, the ban created a downward cascade of Black and Hispanic students through the UC system, pushing many out entirely. They were less likely to earn a B.A., go to grad school, and earn a high salary.

4/ If the "mismatch hypothesis" was true, this would have *improved* academic results for Black and Hispanic students in rigorous STEM classes.

It did not.

5/ Prop 209 also depressed the number of highly-qualified Black and Hispanic students who applied to the University of California--despite the fact that they would have been accepted.

6/ The study also suggests that the additional white and Asian students who enrolled because of the ban probably would have enrolled in another, equally good college elsewhere if affirmative action had continued.

In that sense, 209 was a lose-don't win Proposition.

7/ Notably, this study is the first of its kind. The author used a database of every student who applied to the UC system from 1994 to 2002, including high school transcripts and demographics, course taking, and earnings for more than a decade after graduation.

8/ These kinds of huge administrative datasets provide a new clarity of vision into the consequences of past public policy choices--and whether those choices should change.