In November of 2007, the New York City Department of Education assigned each elementary and middle school a letter grade (A to F) as part of a new accountability system. Grades were based on continuous numeric scores derived from levels and changes in student achievement and other school...

Are teachers' impacts on students' test scores ("value-added") a good measure of their quality? This question has sparked debate partly because of a lack of evidence on whether high value-added (VA) teachers who raise students' test scores improve students' long-term outcomes. Using school...

Are teachersʼ impacts on studentsʼ test scores ("value-added") a good measure of their quality? One reason this question has sparked debate is disagreement about whether value-added (VA) measures provide unbiased estimates of teachersʼ causal impacts on student achievement. We test for bias...

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...