The impact of peer achievement and peer heterogeneity on own achievement growth: Evidence from school transitions

•Estimation of ability peer effects on reading and math achievement growth.•Pupils benefit from abler peers, but high-achievers do so to a smaller extent.•Variation in peer characteristics is largely exogenous.

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 variance in peer skills has no impact on achievement growth – the corresponding estimates are negative, but insignificant.