Much of education policy focuses on improving teacher quality, but most policies lack strong research support. We use student achievement gains to estimate teacher value-added, our measure of teacher quality. The analysis reveals substantial variation in the quality of instruction, most of which...

Charter schools have become a very popular instrument for reforming public schools, because they expand choices, facilitate local innovation, and provide incentives for the regular public schools while remaining under public control. Despite their conceptual appeal, evaluating their performance...