of a two-day freshman orientation program for university students, I find that higher ability peers generate positive … students by 0.05 to 0.08 SD. I provide evidence that the effects result from the formation of lasting social ties, and that …

years. The intervention includes students aged 7-9 and consists of pulling students from their regular mathematics classes … school year. All students, not only struggling students, are pulled out. We find that students in treatment schools increased …