Nber Working Paper Series Who Leaves? Teacher Attrition and Student Achievement

Almost a quarter of entering public-school teachers leave teaching within their first three years. High attrition would be particularly problematic if those leaving were the more able teachers. The goal of this paper is estimate the extent to which there is differential attrition based on teachers' value-added to student achievement. Using data for New York City schools from 2000–2005, we find that first-year teachers whom we identify as less effective at improving student test scores have higher attrition rates than do more effective teachers in both low-achieving and high-achieving schools. The first-year differences are meaningful in size; however, the pattern is not consistent for teachers in their second and third years. For teachers leaving low-performing schools, the more effective transfers tend to move to higher achieving schools, while less effective transfers stay in lower-performing schools, likely exacerbating the differences across students in the opportunities they have to learn. Donald Boyd The Center for Policy Research University of Albany Milne 300 135 Western Ave. Albany, NY 12222 [email protected] Pam Grossman School of Education Stanford University Stanford, CA 94305 [email protected] Hamilton Lankford School of Education, ED 317 University at Albany State University of New York Albany, NY 12222 [email protected] Susanna Loeb 524 CERAS, 520 Galvez Mall Stanford University Stanford, CA 94305 and NBER [email protected] James Wyckoff Curry School of Education University of Virginia P.O. Box 400277 Charlottesville, VA 22904-4277 [email protected]