Teachers Are Not Lemons: An Examination of Spillover Effects When Teachers Transfer Away From Turnaround Schools

Under the Every Student Succeeds Act, whole-school reforms will continue to be a prominent strategy for improving student outcomes in low-performing schools. As reform models have proliferated, so has research evaluating the impact in reform schools. However, previous evaluations have rarely examined unintended spillover effects in nonreform schools. With data from Tennessee, this study uses difference-in-differences models to estimate spillover effects from teachers who transfer when their school begins implementing turnaround reforms. Results show that teachers who transfer tend to be less effective than teachers who stay, and they tend to move into nearby schools that are themselves low-performing. However, after transferring, these teachers produce modest positive spillover effects on student test scores in nonreform schools, which is likely explained by improvements in their effectiveness. Moreover, I find that working with more effective peers is a likely mechanism to explain improved teacher effectiveness after they transfer. Overall, this study draws attention to the need for future educational policy evaluations that quantify both intended and unintended spillover effects.