How teacher turnover harms student achievement

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 850,000 New York City 4th and 5th grade student observations over eight years. The results indicate that students in grade-levels with higher turnover score lower in both ELA and math and that this effect is particularly strong in schools with more low-performing and black students. Moreover, the results suggest that there is a disruptive effect of turnover beyond changing the distribution in teacher quality.