Few topics in education policy have received more attention than teacher turnover—and rightly so. The cost of losing a good teacher can be substantial and is born most directly by students. It is now widely recognized that teachers differ considerably in their ability to improve student outcomes, but discussions of teacher turnover rarely reflect these differences. Instead, we typically treat teacher turnover as uniformly negative. In this paper, we examine teacher turnover in the context of rigorous teacher evaluation to explore three questions. How does teacher turnover affect the quality of teaching and student achievement? How does teacher turnover vary by measured teaching effectiveness? And to what extent is the turnover of effective teachers associated with the evaluation system? We examine these questions employing data from the District of Columbia Public Schools. We find that in general turnover improves teacher quality and student achievement, but that this result masks large differences between teachers identified as more and less effective. Turnover among more effective teachers is relatively low, and when more-effective teachers exit, they infrequently report the evaluation system as a reason.
Document Object Identifier (DOI)