Annual student testing may make it possible to measure the contributions to student achievement made by individual teachers. But would these “teacher value-added” measures help to improve student achievement? I consider the statistical validity, purposes, and costs of teacher value-added...

The vast majority of research and policy related to teacher quality focuses on the supply of teachers and ignores teacher demand. In particular, the important role of school principals in hiring teachers is rarely considered. Using interviews of school principals in a midsized Florida school...