This paper studies the causal impact of adolescent peers who are central in their social network on the formation of social skills and academic performance of fellow students. I conduct a novel large-scale field experiment at selective public boarding schools in Peru with two treatments: (i) more socially central versus less socially central peers, and (ii) higher-achieving versus lower-achieving peers. Peer effects are more pronounced for social skills than academic performance, and both vary by gender. While socially central peers lead boys to better social skills and improve their later-life outcomes, there are no effects for girls. Meanwhile, higher-achieving peers have a zero impact on boys' academic performance and decrease girls' test scores. Gender differences in how students' beliefs about their abilities respond to peer interactions explain both findings, revealing the importance of self-confidence in peer allocation policies.
Choice and Consequence: Assessing Mismatch at Chicago Exam Schools with Joshua Angrist and Parag Pathak. NBER Working Paper 26137. R&R Journal of Public Economics.
The educational mismatch hypothesis asserts that students are hurt by affirmative action policies that place them in selective schools for which they wouldn't otherwise qualify. We evaluate mismatch in Chicago's selective public exam schools, which admit students using neighborhood-based diversity criteria as well as test scores. Regression discontinuity estimates for applicants favored by affirmative action indeed show no gains in reading and negative effects of exam school attendance on math scores. But these results are similar for more- and less-selective schools and for applicants unlikely to benefit from affirmative-action, a pattern inconsistent with mismatch. We show that Chicago exam school effects are explained by the schools attended by applicants who are not offered an exam school seat. Specifically, mismatch arises because exam school admission diverts many applicants from high-performing Noble Network charter schools, where they would have done well. Consistent with these findings, exam schools reduce Math scores for applicants applying from charter schools in another large urban district. Exam school applicants' previous achievement, race, and other characteristics that are sometimes said to mediate student-school matching play no role in this story.
We propose a friendship formation model that distinguishes the role of similarity and physical proximity on friendship patterns. This is a learning-based theory of friendship under which individuals spend time exploring the value of a friendship. The model predicts that friendship patterns exhibit homophily: similarity increases the likelihood of friendship. Higher proximity also increases the likelihood of friendship, and this effect is less pronounced for similar individuals: proximity fosters diversity. To verify the predictions, we use an experiment at selective boarding schools in Peru. While social networks exhibit homophily along multiple dimensions, proximity fosters more diverse friendships. This evidence stands in contrast to the predictions offered by a preference-based theory of homophily.
Cash and Ballots: Conditional Transfers, Political Participation and Voting Behavior with Emily Conover, Adriana Camacho and Javier Báez. Economic Development and Cultural Change 68:2, 541-566 (2020).
Regression Discontinuity in Serial Dictatorship: Achievement Effects at Chicago’s Exam Schools with Atila Abdulkadiroglu, Joshua Angrist, Yusuke Narita, and Parag Pathak. American Economic Review, Papers & Proceedings, 107(5), 240-245 (2017).
Work in Progress
Selective Public Schools and College Outcomes: Evidence Beyond Test Scores with Pía Basurto and Manuel Barrón.
While extensive research documents the impact of selective high schools on test scores, there is little evidence on how they affect longer-term outcomes. This paper studies the effect of elite public schools on college outcomes using an RD design around the admission cutoff of selective high schools in Peru. Despite existing evidence showing no gains on test scores, we find that graduating from an elite public high school increases college application, admission, and enrollment, especially at top private universities. We show that signaling and aspirations can partially explain these findings as selective schools provide students and admission authorities with information about applicants' skills in a context without a high school exit standardized exam. We provide consistent evidence of other signals of ability, as students graduating from these schools also benefit from marginally obtaining the IB diploma.