Are teachers' impacts on students' test scores ("value-added") a good measure of their quality? This question has sparked debate largely because of disagreement about (1) whether value-added (VA) provides unbiased estimates of teachers' impacts on student achievement and (2) whether high-VA teachers improve students' long-term outcomes.…

One way to improve struggling schools' access to effective teachers is to use selective transfer incentives. Such incentives offer bonuses for the highest-performing teachers to move into schools serving the most disadvantaged students. In this report, we provide evidence from a randomized experiment that tested whether such a policy intervention…