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.
Choice and Consequence: Assessing Mismatch at Chicago Exam Schools with Joshua Angrist and Parag Pathak. Journal of Public Economics, forthcoming. Publisher version here.
Uncovering Peer Effects in Social and Academic Skills. American Economic Journal: Applied Economics 15(3), 35-79 (2023). Publisher version here.
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
The Signaling Value of Elite High Schools with Pía Basurto, Manuel Barrón, and Martín Carbajal. Draft available upon request.
This paper examines schools' effects on college outcomes in Peru, a country without a high school exit standardized test, and relates these effects to school reputation and value-added on learning. We first estimate the impact of selective public exam schools on college outcomes using an RDD around the admission cutoffs. Despite little evidence of gains in learning, graduating from these schools improves college applications, admissions, and enrollment, especially at top private universities. We provide evidence that this result is partially explained by selective exam schools serving as a signal about applicants' abilities. The effects are similar for other signals, such as marginally obtaining the IB diploma. We next estimate and validate school value-added on college outcomes for all high schools in Peru. Consistent with the exam school effects, school gains on test scores are not predictive of effects on college outcomes after controlling for average high school graduates' characteristics. These results are consistent with distortions in the transition from high school to higher education due to information frictions.
Gender Stereotypes and Peer Recognition with Manuel Barrón, Pía Basurto, and Juan Francisco Castro. Draft available upon request.
This study explores how interventions aiming to reduce the gender gap in STEM fields affect peers' recognition of women's abilities. We study the effects of an intervention that combines STEM female role models and feedback on gender-science stereotypes on students' perceptions of each other. As peer influence could affect how individuals form opinions about others, we account for potential spillovers in a two-phase experimental design. In the first phase, classrooms are randomly assigned to different saturation levels of the intervention. In the second phase, conditional on classroom saturation levels, students are assigned to the treatment. The results show treatment but no spillover effects on attitudes towards women in STEM fields. However, we find evidence of treatment and spillover effects on recognizing women's math skills via more female nominations for the math component of an inter-classroom contest. This shift in nominations does not affect performance, reducing concerns about potential efficiency costs. Our results suggest that targeting peers to recognize women's STEM abilities can be highly effective due to the spillover effects when forming opinions about others.
Online Learning and Labor Market Outcomes: Experimental Evidence from Colombia with Stephanie Majerowicz. Draft available upon request.
This paper studies the impact of MOOC certificates on formal labor employment. We leverage an RCT of a program offered by a large MOOC provider to public organizations during the pandemic, where around 13,000 beneficiaries among 21,000 applicants were randomly selected to receive free MOOC certificates. We track participants in formal labor markets for one year after the program ended. Despite the free certificates, the take-up rate is low: 50% of treated beneficiaries enroll in at least one course but only 7% complete them. Reduced form treatment effects show positive but insignificant effects on formal labor employment. An event study estimating the impact of course completion and earned certificates shows significant increases of 10% on formal employment, with higher effects for low-income beneficiaries. These results reveal that while MOOCs can potentially improve labor market outcomes, there should be complementary interventions to increase their completion.