








This article investigates how Michigan's charter school policy influences the composition of students by race and socioeconomic status in urban traditional public schools. Using 2 years of student-level data in Michigan's urban elementary and middle schools, the dynamic student transfers between charter schools and TPSs are analyzed through a series of hierarchical generalized linear models. The two-way transfer analysis shows that the student sorting under the charter school program tends to intensify the isolation of disadvantaged students in less effective urban schools serving a high concentration of similarly disadvantaged students. The findings imply that a challenge for the state policy makers is to help disadvantaged students who are left behind in the most disadvantaged schools, without significantly reducing the benefits to students who take advantage of school choice.
