Mandatory summer school and student achievement

Using administrative data from a large school district, I exploit the fact that students are mandated to attend summer school based on a discontinuous function of their score on year-end exams to identify the effect of summer school attendance on achievement. I find an average effect of about .12 standard deviations for both math and reading achievement, an effect size on the low end of the range of prior estimates. These averages mask considerable heterogeneity, however, with effect size estimates ranging from just below zero to one-quarter of a standard deviation. The estimates on the upper end of the range presented here suggest that summer school may be a more cost-effective way of raising student achievement scores than class-size reductions.