In a recent post, Brookings Fellow Grover “Russ” Whitehurst offered an argument against public funding for universal pre-K. With President Obama calling for the federal government to work with states to “make high-quality preschool available to every child in America,” we can expect the policy conversation regarding the value of universal pre-K to rise from a simmer to a boil. This makes it important to understand what the research shows, and how it can inform sound public policy.

Whitehurst calls for an evidence-based approach to policy, and selects several studies to support his argument that universal pre-k would not be a good public investment. He turns first to the research on Head Start, which has been disappointing to its own supporters and red meat to its opponents. Yet using the Head Start research in a discussion of universal pre-K is an odd choice. Most prominently, as a program that serves children living in poverty, Head Start is not a universal pre-K program. The Head Start model is quite different from the pre-K model in other ways as well, notably its emphasis on health and social services for families, engagement of families in their children’s learning, and serving children with special needs. Head Start and state pre-K programs are plainly different. Nevertheless, Whitehurst asks, “If a year of Head Start does not improve achievement in elementary school, should we assume that a year of state pre-K does?” The research suggests that the answer is, “yes,” with several studies finding gains from pre-K programs that are two or more times greater than those from Head Start.

Whitehurst then cites a study of Georgia’s universal pre-K program, noting that its author suggests the program is not cost-effective. Again, this study is an odd choice for an argument against universal pre-K. The study is not an analysis of cost-effectiveness, but a look at whether the gains in learning attributed to the pre-K program persist into elementary school, and for which children. The author concludes, “Universal pre-K had a positive impact on the academic achievement of children in Georgia.” In the final paragraph of her discussion, the author offers a “simple back-of the envelope” calculation of cost effectiveness, which “should be interpreted with caution.” Indeed, the calculation considers wage gains, but not any of the reductions in social costs that have been associated with preschool enrollment. Far more complete studies suggest that universal pre-K would be cost-effective. Whitehurst says nothing about these studies, dismisses the results from the highly cost-effective Perry Preschool and Abecedarian programs, and ignores longitudinal research on a large-scale preschool program in Chicago that had returns of $10 for every $1 invested. It’s also worth noting that many advocates of universal pre-K argue that it could be offered on a sliding-scale fee basis to offset costs while assuring that all families have access.

Whitehurst next cites a study of the Texas pre-K program, which found positive results on a range of outcomes, and notes that the benefits were largest for children at highest risk. This is consistent with other research indicating that highly disadvantaged children benefit the most from high-quality preschool, but does not imply that children from working-class or middle-income families do not benefit. The relationship between children’s economic background and cognitive skills appears to be linear, indicating that as family income rises, the potential benefits of preschool do not disappear when families earn more than the poverty line. The reason that middle-income families have low participation rates in preschool is not that they don’t need or want what lower-income and higher-income families are getting, but that they have been priced out of the private market for preschool and do not qualify for publicly funded options. Universal pre-K would address this problem.

Finally, Whitehurst tries to discredit a widely cited study in Oklahoma, which found that universal pre-K was associated with significant gains in cognitive outcomes for children from a variety of economic backgrounds. Whitehurst suggests that the authors’ methodology is fundamentally flawed because it compares two groups of children who differ slightly in age to estimate the effect of a year in pre-K for the marginally older group. Yet the study employs a regression discontinuity design, which is highly respected because it greatly reduces the threat of such selection bias. In addition, the authors test their hypothesis in multiple and increasingly strict ways, all indicating statistically significant benefits of pre-K enrollment, and weakening Whitehurst’s critique.

Whitehurst concludes with a call for better program-level and child-level data to allow states to improve their programs and parents to choose among preschools by comparing their quality. Indeed, with federal help, multiple states are creating these very systems of data-collection and quality ratings that parents can use to evaluate programs for their children.

The real issue that early childhood policymakers and researchers face is not whether preschool is a worthy investment. That question has been largely settled. Far more important is the question of how best to use scarce public resources to create and sustain high-quality preschool programs as the states widen access to more families. In addition to many studies that point to instructional quality, my own research published by The Century Foundation suggests that socio-economic diversity within classrooms is an important aspect of preschool quality, and that policymakers could enhance the learning of preschool children by fostering diversity in high-poverty programs.

The efforts of policymakers to build systematic supports for quality are critical to realizing the potential of preschool for all children. Let’s not get diverted from this central task by spending money to find out whether all families should have affordable access to good preschools. We already know the answer to that one.

Updated: Tuesday, February 19, 2013 to clarify the relationship between family income and the benefits of preschool.

Jeanne L. Reid is a Research Scientist at the National Center for Children and Families at Teachers College, Columbia University. Read her chapter Socioeconomic Diversity and Early Learning: The Missing Link in Policy for High-Quality Preschools found in our publication The Future of School Integration.

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