Teacher Turnover and Student Achievement in DC Public Schools
*Names in bold indicate Presenter
Using longitudinal data on teachers and students in tested grades and subjects from 2009-10 to 2012-13, we examine how different forms of turnover (e.g., voluntary attrition or forced separation) influence subsequent student achievement outcomes within the affected school-grade cells. This approach parallels methods employed by Chetty, Friedman and Rockoff (2014) as well as Rivkin, Hanushek, and Kain (2005), Jackson and Bruegmann (2009), and Ronfeldt, Loeb, and Wyckoff (2013). In general, we suspect teacher turnover is likely to be non-random: the unobserved school traits that influence teacher turnover are also likely to influence student achievement. However, the variation isolated by our approach – the year-to-year variation in teacher turnover within given school-by-grade cells – may be a plausibly exogenous determinant of student achievement. To increase our confidence that IMPACT caused the student achievement changes we observe through changes to teacher quality we also estimate the “first-stage” effect of turnover on IMPACT scores as well. In preliminary analyses we find evidence that IMPACT-induced exits improve math teacher performance in a school-grade cell by more than a standard deviation in the next year and improve student achievement outcomes in math by 20 percent of a standard deviation in high poverty schools. Results in reading are qualitatively similar, but smaller. Because teacher turnover during the IMPACT era is closely related to its design features, these results provide encouraging preliminary evidence that IMPACT has shaped teacher quality and student performance through changes to the composition of the teacher workforce in DCPS.