Peer heterogeneity, school tracking and students'performances: evidence from Pisa 2006

This paper analyses the interaction between school tracking policies and peer effects in OECD countries. Using the PISA 2006 dataset, we show that the linear peer effects are stronger and more concave-shaped in the early-tracking educational system than in the comprehensive one. Second, and more interestingly, the effect of peer heterogeneity goes in opposite directions in the two systems. In both student- and school-level estimates, peer heterogeneity reduces students’ achievements in the comprehensive system while it has a positive impact in the early-tracking one. For late tracking countries, this result appears driven by pupils attending vocationally-oriented programs. Finally, peer effects are stronger for low ability students in both groups of countries.