Abstract
Students' study time is a key input in the education production function, yet its determinants remain poorly understood. We examine whether students' study time is shaped by their peers, focusing on a novel channel for peer effects: beliefs about peers' study behavior. Using a randomized controlled trial with incentivized measures, we show that middle school students substantially underestimate how much time their classmates spend on schoolwork, and that reducing these misperceptions through an information treatment increases study time among students who initially studied relatively little—by about 25 minutes per week, or a 20% increase compared to the control group. We find that the intervention shifts students' beliefs about the relative importance of effort versus innate ability, suggesting this as a key mechanism behind the behavioral response. Leveraging the partial-population design of our experiment, we further document positive spillover effects on untreated classmates' beliefs and well-being.