Running head: STUDENT MOBILITY IN MILWAUKEE 1 Student Mobility in Milwaukee: The Effects of School Transfers on Mobile and Non-Mobile Students

This article explores student mobility in the Milwaukee Public Schools (MPS) and its effects on student achievement. An urban district with plentiful opportunities for school choice, Milwaukee has a transient student population. From 2003-04 through 2007-08, 11 % of MPS students switched schools or left the district between the fall and spring of a given school year, while 22% were mobile between the spring of one year and the fall of the following year. Using both student fixed-effects and instrumental variables approaches, we examined the effects of this mobility on both the students who moved and their classmates who did not. We found evidence that mobile students ’ test score gains dropped immediately after they switched schools, but these students typically recovered their losses in the subsequent year. We detected modest but statistically significant negative effects of grade-level turnover on non-mobile students’ academic achievement