We exploit rules of class formation to identify the causal effect of increasing the number of immigrants in a classroom on natives test scores, keeping class size constant (Pure Composition Effect). We explain why this is a relevant policy parameter although it has been neglected so far. We show...

Conventional wisdom suggests that the stocks of human capital were one of the few positive legacies from communism. However, if factories under communism were so inefficient, why would the education system not have been? Using the education production function approach and new data on...