The Advanced Placement (AP) program is nearly ubiquitous in American high schools and is often touted as a way to close racial and socioeconomic gaps in educational outcomes. Using administrative data from Michigan, I exploit variation within high schools across time in AP course offerings to identify the causal effect of AP course availability on college choice and degree attainment. I find that higher income students, White and Asian students, and higher-achieving students are more likely to take advantage of additional AP courses when they are offered, thus widening existing gaps in course-taking. I find little evidence that additional AP availability improves college outcomes for any students. Expanding access to AP courses without additional incentives or support for disadvantaged students to succeed is unlikely to address educational inequality.
Beliefs about relative academic performance may shape field specialization and explain gender gaps in STEM enrollment, but little causal evidence exists. To test whether these beliefs are malleable and salient enough to change behavior, I run a randomized controlled trial with 5,700 undergraduates across seven introductory STEM courses. Providing relative performance information shrinks gender gaps in biased beliefs substantially and closes ten percent of the gender gap in subsequent STEM course-taking. The gap closes due to men taking fewer STEM credits; women’s behavior is unchanged, implying that male overconfidence rather than female underconfidence contributes to gaps in specialization. Beliefs matter, but may not be a useful target for facilitating female STEM participation.