This paper estimates ability peer effects on achievement growth in reading and math. It exploits variation in peer characteristics generated at the transition from primary to secondary school in a sample of Berlin fifth-graders. As will be discussed in detail, this variation is exogenous in large parts. Results are similar for both achievement measures: pupils benefit from abler peers, but high-achievers do so to a smaller extent. The estimated impact of the variance in peer skills is negative, but insignificant.
ability peer effects in upper-secondary school natural experiment