A new review of research studies on voucher programs over the past decade in the United States has found no clear positive impact on student academic achievement. Students using government funded vouchers to attend private schools did not generally attain higher test scores than public school students.
The report also found that much of the recent voucher research has been carried out or sponsored by pro-voucher organizations. It recommends greater scrutiny to ensure future studies are not biased.
The report reviewed and synthesized the findings of 27 research studies on voucher programs conducted since 2000. It was published by the Center on Education Policy (CEP), one of the leading sources of education research in the US.
Publicly funded school vouchers allow parents to receive money from the government that they can then use to pay tuition at a private school of their choice. The CEP review focused on those programs. It did not examine studies of privately funded vouchers; tax credits to families or corporations for payments made for children’s private school tuition; or voucher programs intended solely for students with disabilities.
Vouchers are very controversial in the US. Proponents maintain that vouchers give low-income children an opportunity to improve their learning by transferring from lower-performing public schools to better performing private schools – an option already available to families who can afford to pay fees. Proponents also assert that vouchers create an incentive for public schools to improve by fostering competition and can be a more efficient and cost effective way of funding education than providing money to public bureaucracies.
Opponents contend that vouchers unfairly channel tax dollars to private schools without requiring these schools to abide by the same requirements as public schools in such areas as accountability, testing, or special education. Opponents also assert that vouchers drain much-needed resources, as well as motivated students and parents, from financially strapped public schools and affect only a small number of children without providing the comprehensive reforms needed to strengthen the entire public education system.
The longer-term studies of the publicly funded voucher programs in Milwaukee, Cleveland, and Washington DC have generally found no clear advantage in academic achievement for students attending private schools with vouchers. The gains in achievement were about the same for low income students receiving vouchers as they are for comparable public school students.
For example, students in grades 3-8 who participated in the Milwaukee voucher program had rates of achievement growth over three years that were similar to those of a random sample of Milwaukee public school students with analogous characteristics, according to a comprehensive study by the School Choice Demonstration Project at the University of Arkansas.
When adjustments were made for students’ prior achievement, mobility, and minority status, the overall achievement of students who participated for several years in the Cleveland voucher program did not differ significantly from that of comparable public school students, according to a long-term evaluation by Indiana University researchers. A re-analysis of test data from the Cleveland program by researchers at the National Center for the Study of Privatization in Education found no academic advantages for voucher users in Cleveland.
Low-income students who were awarded private school vouchers through the Washington DC program showed no significant differences in reading and math achievement from a control group of students who did not receive voucher awards, according to a study conducted by researchers from several organizations and universities for the U.S. Department of Education.
Some studies found limited test score gains for voucher students in certain subject areas or grade levels. However, the CEP report noted that these findings are inconsistent among studies, and the gains are not statistically significant, not clearly caused by vouchers, or not sustained in the long run.
Studies of Washington DC and Milwaukee found higher high school graduation rates among voucher students. However, the CEP report found that this advantage becomes less significant when family characteristics are taken into consideration, such as income and education. The studies could not determine whether higher graduation rates are a direct result of practices in voucher schools.
Some studies have shown larger gains in student achievement in public schools most affected by voucher competition than in other public schools. For example, the University of Arkansas study found that students in public schools that were more affected by voucher competition showed slightly greater gains in achievement than students less affected by voucher competition. However, many of these studies were conducted by groups with a clear pro-voucher position according to the review and other studies find little evidence of a response by public schools to competitive pressure from vouchers.
The report notes that many voucher studies of the past decade have been sponsored or conducted by organizations with clear positions or mission statements in favour of vouchers and that this raises issues about the objectivity of these studies.
Much of the recent research on vouchers has been sponsored or funded by organizations with a clear viewpoint in favour of vouchers. This complicates efforts to determine the objectivity of studies. Voucher research involves complex, technical decisions about methodology. Examples include decisions about whether to control for student, family, or school variables and which variables to use; which students to use as a control group; and to what extent public schools are affected by competition from vouchers. If researchers are not completely objective, they may make these types of decisions in a way that is most likely to yield findings that support their own views. This situation points to the need for careful scrutiny to ensure a particular study is not biased. [p.47]
The report recommends that future voucher studies should be designed, conducted and reported in an objective and rigorous way. They should be subjected to outside scrutiny of study methods and guidance from objective expert panels. In addition, those conducting voucher studies should publicly reveal which organisations have sponsored and funded the study.
Alexandra Usher and Nancy Kober, Keeping Informed about School Vouchers: A Review of Major Developments and Research, Center on Education Policy, July 2011.