Working Papers

Peer Effects on Social and Academic Skills

This paper uses a novel large-scale field experiment at selective public boarding schools in Peru to study how more sociable and higher-achieving peers influence students' outcomes. Peer effects are more pronounced on social skills than on academic performance, and both vary by gender. While more sociable peers lead boys to have more friends and develop better social skills, it does not affect girls' outcomes. These positive effects persist in later-life as more sociable peers reduce the dropout rate and increase enrollment at better colleges for boys. Meanwhile, having higher-achieving peers has, on average, zero effect on boys' academic performance and a negative impact on girls. Gender differences in students' beliefs about their own abilities 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.

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.


Cash and Ballots: Conditional Transfers, Political Participation and Voting Behavior with Emily Conover, Adriana Camacho and Javier Báez. Economic Development and Cultural Change (forthcoming).

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.

Work in Progress

The Signaling Value of Elite High Schools: Evidence from Higher Education in Peru  with Pía Basurto and Manuel Barrón.

This paper studies how the high school's identity affects students' sorting in the higher education market in Peru, a country without standardized tests at the end of high school. We first examine whether providing low-income students with mechanisms to signal their ability improves their higher education outcomes. Our results show that graduating from an elite public high school increases higher-education enrollment and quality even without noticeable gains in human capital. Likewise, obtaining the IB diploma by the minimum margin increases enrollment and admission at top private institutions. These effects are more pronounced on a special admission mode, under which accepted applicants waive the regular admission tests. We also estimate value-added models on higher education outcomes and find consistent evidence with top private institutions statistically discriminating based on sending high schools. 

Homophily in Social Networks: Preferences vs. Information with Arda Gitmez.

We propose a new link formation model to separately identify whether preferences or information cause homophily in social networks. When preferences are the cause of homophily, reducing the cost of forming a link would increase homophily. By contrast, when learning is the leading cause, reducing this cost would decrease homophily. We use the model and an experiment at selective boarding schools in Peru to show that while social networks exhibit homophily along multiple dimensions, reducing the cost of forming a link fosters more diverse friendships. These results are consistent with individuals receiving more information from those similar to them rather than preferences.