The study examined the effectiveness of the Milwaukee Parental Choice Program (MPCP), which provides vouchers for low-income students to attend private schools. The study examined the four-year academic achievement growth of more than 600 students who were given a voucher in the 2006-07 school year, compared to the academic achievement growth of a matched sample of students who had attended Milwaukee public schools. The study reported that students who began participating in the MPCP in the 2006-07 school year had statistically significantly higher reading achievement in the 2010-11 school year than comparison students, with an effect size of 0.15. There was no difference in math achievement. The study cannot "meet the What Works Clearinghouse (WWC) evidence standards" because it is not a randomized controlled trial. The study may be able to "meet WWC evidence standards with reservations" because the authors established that their quasi-experimental matching design resulted in equivalent groups of MPCP students and comparison students on test scores and demographic characteristics in 2006. However, because of a change in district policy in the final year that applied only to schools receiving voucher students, it is possible that the observed effects were not solely due to the MPCP. A more thorough review (forthcoming) will examine the issue further to determine the study rating. [The following study is reviewed in this What Works Clearinghouse Quick Review: "MPCP Longitudinal Educational Growth Study: Fifth Year Report. SCDP Milwaukee Evaluation Report #29." To access this report, see ED530071.]