We examine college students' interaction within classrooms and estimate peer effects on their academic performance. We exploit a unique seating rule at a university in South Korea, known as the fixed‐seat system. We propose a novel identification strategy based on students' repeated interaction. Our findings show that a student's performance in a class is significantly influenced by his or her next‐seat neighbor's ability. The effect is heterogeneous, varying by student and class characteristics. Also quantile regressions reveal that peer effects are significant among below‐average students and among those at the top end.

Peer effect classroom seating rule academic performance college students IV quantile regression personality C31 I21