Working Papers

Social and Academic Peer Effects: Experimental Evidence from Selective High Schools in Peru


This paper estimates peer effects on social and academic outcomes using a large-scale field experiment at selective public boarding schools in Peru. I use a new experimental design that generates substantial variation in peer characteristics. The experiment randomizes two types of neighbors into dormitories: (1) less or more sociable (identified by the social network) and (2) lower- or higher-achieving (determined by admission scores). Boys with more sociable neighbors have more connections, a better network position, and more advanced social skills. There are no effects on social outcomes for girls. Academic peer effects are, on average, a precise zero, with some negative impacts on lower-achieving girls. Differences in how peers affect boys' and girls' beliefs about their own abilities explain these findings. I also rule out friendships as the ultimate driver of peer effects.

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.