I estimate the effect of class size on scholastic achievement using that schools are only in session during the school year and out of session during the summer. This seasonal feature of the schooling system makes it possible to control for unobservable pupil characteristics affecting both the...

Using that schools are in session during the school year and out of session during the summer, it is possible to isolate the effect of schooling on learning. This natural experiment situation can also be used to see whether schooling compensates for disadvantageous social backgrounds. Using a...