Researchers and policymakers often assume that teacher turnover harms student achievement, but recent evidence calls into question this assumption. Using a unique identification strategy that employs grade-level turnover and two classes of fixed-effects models, this study estimates the effects of teacher turnover on over 600,000 New York City 4th…

Studies have found substantial sorting of teachers across schools, with the schools with the highest proportions of poor, non-white, and low-scoring students having the least qualified teachers as measured by certification, exam performance, and inexperience (Lankford, Loeb and Wyckoff, 2002). Yet, there have been substantial changes in the…