Tracking programs have been criticized on the grounds that they harm disadvantaged children. The bulk of empirical research supports this view. These studies are conducted by comparing outcomes for across students placed in different tracks. Track placement, however, is likely to be endogenous...

Most evaluations of education policies focus on their mean impacts; when distributional effects are investigated it is usually by comparing mean impacts across demographic subgroups. We argue that such estimates may overlook important treatment effect heterogeneity; in order to appreciate the...