A Survey of Results from Voucher Experiments: Where We Are and What We Know

When I began doing research on school choice in 1995 there was relatively little solid, empirical information on the subject. At that time there was only one choice program, in Milwaukee, and the data from that program had already been withheld from examination by the research community for five years with little sign that it would become available soon.1 Researchers wishing to examine the effects of school choice were limited to collecting evidence from public and private schools and extrapolating to what would happen under a choice system. A leading researcher following this approach, James Coleman, consistently found that private school students performed better academically than public schools students after controlling for a host of observed background differences.2 Coleman and others also found that private schools, while educating a lower proportion of minority students, more evenly distributed minority students, producing better racial integration than that found in public schools. From these findings Coleman and others suggested that providing vouchers or tax credits for families to select the school of their choice, public or private, would increase academic achievement and improve racial integration in schools.

Many education researchers remained unconvinced. Unobserved and difficult to measure differences between families that select public and private schools might account for the apparent academic edge that private school students displayed, these researchers argued. Unfortunately, there was no way to respond to this objection fully as long as one was comparing families that chose a private school to those that did not. No matter how many controls were introduced for background differences, it was always possible that some other unobserved factors really explained the differences in outcomes. Many education researchers also remained unpersuaded that school choice would help promote integration. The lower percentage of minority students in private school, critics argued, was a more telling indicator of the effect of choice on integration than was the distribution of those students within the private sector.

In the absence of new sources of data, research on the effects of school choice remained deadlocked along these lines for many years. To be sure, innovative arguments were advanced by John Chubb and Terry Moe, but their work was more support for a theory of how school governance related to organization efficiency than it was a source of direct evidence on the consequences of school choice. And various articles and books were authored by critics of school choice, such as Henry Levin, Amy Stuart Welles, and Peter Cookson, but their arguments were largely based on theoretical assumptions, analogies to foreign systems, or their particular reading of the debate over Coleman’s work.3

But starting in 1996 a flood of new data became available, greatly expanding what we know about the effects of school choice. First, John Witte released to other researchers the data he had obtained on the Milwaukee school choice program. Second, Cleveland began operating the second publicly funded school choice program and made at least some information available to different researchers. And third, several privately funded school choice programs were specifically designed to allow for rigorous examination of their effects. As a result of all of these new programs and studies we now know quite a lot about the effects of school choice.

The evidence on school choice can be organized as addressing three questions: 1) What are the academic effects of school choice on the families that choose their school? 2) What are the academic effects of school choice on the public school system? And 3) What are the effects of school choice on the civic values and integration that we wish schools to promote? The evidence that addresses the first question, the academic effects of choice on the choosers, is now fairly strong. Our knowledge about the later two questions is still limited but growing stronger. Of course, much can still be learned on all three questions, and some people will never be satisfied with the quality or quantity of evidence produced. But it is fair to say that incredible progress has been made in the last several years in developing a solid empirical understanding of the effects of school choice programs.

It is also important to note that despite some well-publicized disagreements over research findings in recent years, there is a remarkable amount of consensus among the researchers who have collected and analyzed the data from recent programs on the general direction of the effects of school choice. These researchers largely differ on the confidence with which conclusions can be drawn and the inferences that can reasonably be made for shaping public policy, but they do not differ on their general assessments of the programs they have examined. That is, all of the researchers who have served as evaluators of the publicly-funded choice programs in Milwaukee and Cleveland, as well as the privately-funded programs in Washington, D.C., Dayton, New York, and San Antonio, agree that these programs have been generally positive developments and have supported their continuation, if not expansion. If one only examined the competing interest group and research community spin on the various evaluations instead of reading the evaluations themselves one might easily miss the level of positive consensus that exists. This positive consensus is all the more remarkable given the politically contentious nature of the issue and the rewards scholars have for highlighting disagreements with one another.

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