In this paper, the authors estimate the effect of the Milwaukee Parental Choice Program (MPCP, or the Milwaukee voucher program) on integration in public and private schools. Their first question is straightforward: Do the student bodies at private schools participating in MPCP have a racial composition that more closely or less closely resembles the racial composition of school-age children in the Milwaukee metropolitan area than do Milwaukee Public Schools (MPS)? The general answer is that MPCP and MPS schools are about equally representative of the racial composition of the broader community in which they are located; however, both sectors have racial compositions that deviate significantly from the Milwaukee metro area. Their second question comes in two parts: When a student in Milwaukee Public Schools transfers to a different school (either within MPS or into the private sector with a voucher), how does that transfer affect the racial integration at (a) the student's originating public school and (b) the school receiving the student? As to both of these sub-questions, they measure integration by proximity to the racial demographics of the overall metropolitan area. In general, the authors find that students who switch schools in Milwaukee overwhelmingly tend to (a) improve racial integration at their originating school and (b) worsen integration at their receiving school, whether that receiving school is within MPS or part of the voucher program. Furthermore, the differences between MPS-to-MPS and MPS-to-MPCP switches are negligible. Finally, their third question considers if the two sectors differ in the degree to which their student bodies are racially homogeneous. To answer this question, the authors compare the percentage of schools that are racially homogeneous between the two sectors. They find that, while racially homogeneous schools make up a sizeable portion of schools in both sectors, the two sectors are not significantly different in the degree to which they have racially homogeneous schools. Overall, their results show that the Milwaukee voucher program is currently neutral in its effect on racial integration. This result is different from previous integration research on the Milwaukee voucher program that found positive impacts. The reason, the authors suspect, is that Milwaukee has already allowed residents to choose any public school regardless of geographic districting, which in turn means that over time public schooling has become less tied to patterns of residential segregation than in most metropolitan areas. The remainder of this paper proceeds as follows: first, the authors present a review of the relevant literature on the effects of school voucher programs on integration. Next, they provide a brief description of their data and present the results of their analyses intended to answer the three questions outlined above. Finally, they conclude with a discussion of their findings. (Contains 9 tables and 7 footnotes.)