We study the impact of exposure to high achievers, identified through teacher rankings of students’ performance, on cognitive and non-cognitive skills using a unique randomized experiment from Ecuador. Students in each school are randomly assigned to classrooms in every grade from 1st to 6th. The proportion of high-achieving peers varies across grades and classrooms due to the random assignment. We find that exposure to high achievers reduces test scores in math and executive function. Additionally, male students influence only their male peers, while female students affect only female peers. Competition within the classroom intensifies peer effects, with the impact of high achievers concentrated among students in the top quintile of the previous year’s test scores and those attending smaller schools. Finally, as with other school inputs, the effects of 1st-grade peers are stronger but fade over time. We also find reductions in self-reported happiness, but no impacts on non-cognitive skills.

This paper explores the impact of exposure to violence during childhood (0-9 years old) on socioemotional skills and risky health behaviors in adolescence. Using data from the Colombian Longitudinal Survey and municipality-level administrative data, I exploit the within-municipality cross-cohort variation of terrorist attacks among teenagers living in urban areas of Colombia. I find robust evidence that exposure to terrorist attacks is associated with a 0.046 SD increase in socioemotional difficulties experienced, mainly driven by increased hyperactivity, and a 6.5% increase in the probability of drinking. These results highlight the potential consequences of violence on new outcomes related to adolescent health.

In this document we analyze the impacts of a large-scale intervention that provided access to daycare centers for children in low-income neighborhoods in the city of Rio de Janeiro. Our results suggest that the intervention had a positive impact on enrollment rates and on the number of years children were enrolled to daycare during early childhood. We also find that winning the lottery had a positive effect on how regularly children attended primary school during the academic year. Because of the high attrition rates in the sample, we are unable to conclude whether the lottery had a positive impact on medium-term academic outcomes like standardized tests scores and overall grades.