We study the effects of peers on school achievement, with detailed data on children making the same primary to secondary school transition in consecutive years in England. Our estimates show that secondary school composition, on entry at age 12, affects achievement at age 14, although the effect...

We present a theory explaining the impact of ability tracking on academic performance based on grading policies. Our model distinguishes between initial ability, which is mainly determined by parental background, and eagerness to extend knowledge. We show that achievements of low ability...