In the large empirical literature that investigates the causal effects of education on outcomes such as health, wages and crime, it is customary to measure education with years of schooling, and to identify these effects using the exogenous variation provided by school reforms increasing...

Secondary schools in the developed world differ in the degree of differentiation and in the first age of selection of pupils into different tracks. In this paper, we account for the heterogeneity of tracking time with a simple stochastic model which conjugates the returns from specialization...