With last night's State of the Union proposal to expand pre-k access, there's a lot of buzz out there on pre-k today--and, as always with D.C. or the internet, a lot of misconceptions. I want to clear up a few common myths about the evidence on pre-k. The following statements are not true.
The evidence for pre-k impacts comes exclusively from "boutique" programs that were small, expensive, and can't be replicated: Not true. To be sure, the most frequently cited study of pre-k impacts, the High/Scope Perry Preschool Study, which employed "gold standard" randomized controlled tried methods, does fit this characterization. But, as I wrote recently, we now have a much more robust and varied body of evidence on the impact of quality pre-k: The $7 return on every dollar invested in pre-k figure from the President's speech most likely comes from the Chicago Longitudinal Study, a quasi-experimental long-term study that tracked outcomes for nearly 1,000 children Chicago children participating in a Title I-funded pre-k program operated by the Chicago Public Schools and compared them with a random sample of similar children who did not participate. We also have high-quality regression discontinuity design studies from Oklahoma and New Jersey documenting significant learning gains for pre-k students, both randomized controlled trial and RDD designed studies in Tennessee finding positive results for Tennessee's Voluntary Pre-k Program. And these are not the only states where research suggests pre-k works. Not to mention a recent CALDER study finding that children participating in Texas' pre-k program make early learning gains that are sustained through third grade--and Texas is the very definition of scale.
Pre-k effects always "fade out": This one's a little more complicated. This claim is largely pegged to the Head Start Impact Study, which found that Head Start children make gains relative to comparison students during the pre-k year, but those differences disappear by the end of 2nd grade, as well as to earlier studies of Head Start. There is a complicated debate over evidence of Head Start fade-out, and some very modest evidence of long-term effects. But we don't have to parse the Head Start debate to reject the assertion that all pre-k gains always fade out. We can look, again, at the Chicago Longitudinal Study, which found evidence of positive long-term impacts on school achievement at age 14, special education placement, grade retention, and high school completion. And we can look at studies of state-funded pre-k programs in Texas and New Jersey that find children in these programs make gains relative to nonparticipants that last at least into the early elementary grades. All that suggests that pre-k results by no means have to "fade out."
Pre-k only works for poor kids: Again, not true. Because most of the high-quality studies we have of pre-k programs tend to focus on interventions designed for at-risk children, or public programs that target enrollment to low-income students, the bulk of evidence we have at pre-k is from programs serving poor or low-income kids. But that doesn't mean that pre-k only benefits low-income kids. Research from Oklahoma's universal pre-k program in Tulsa found that children from all socio-economic groups benefited from pre-k, although poor children, who started out further behind, may have reaped the greatest benefits in terms of increased school readiness. Data also indicates that "near poor" and moderate-income children, whose parents make too much to qualify for subsidized programs but too little to afford pre-k themselves, are actually less likely than poor kids to attend pre-k--even though some of these children are also at risk for the types of educational challenges that pre-k helps mitigate.
All Pre-K programs deliver impressive results: Taken together, the evidence on the positive impacts of pre-k described above is among the strongest body of evidence we have supporting any educational intervention or program. But that doesn't mean that pre-k always works, or that it works equally well in all circumstances. As should be obvious from the information above, some research on Head Start has reached different conclusions about lasting impacts from that pre-k program than some studies of state pre-k or other interventions have about those programs. Similar, research looking across multiple state pre-k programs finds considerable variation in both program quality features and impacts. As with everything in education: Implementation matters. That's why the details of any state or federal pre-k proposal--not just the big picture quality standards, but how the program will actually work with providers to ensure quality supply--are so, so critical.
Pre-k pays for itself: Ah, that $7 to $1 return again. Doesn't that mean pre-k pays for itself? Well, no. At least not in the sense that's relevant to questions of how governments can fund pre-k programs. For starters, those returns are long-term returns, and governments that want to expand pre-k access need to find ways to pay for those programs now, before any returns are in hand. Further, the largest share of the widely cited pre-k "savings" are in the form of benefits that accrue to participants themselves (ie, increased earnings) or to a diffuse public (ie, reduced crime victimization), not to taxpayers or governments. That's great for people who benefit, but means these benefits can't be tapped to "pay for" pre-k. Evidence suggests that pre-k does result in increased tax revenue and reduced costs for government, particularly reductions in special education and grade retention costs while children are in school, and reductions in welfare and incarceration costs when they become adults. But in our federal system, these benefits accrue at a variety of levels of government and different types of programs, and there are no easy mechanisms to capture many of these savings to "pay for" pre-k costs. For example, is the federal government going to reduce its annual appropriations for IDEA if its investments in pre-k lower special education placement rates--unlikely. There are ways we could design policies to better capture savings related to pre-k and use them to help offset some costs over the long-term, but that's not typically what people mean when they say pre-k pays for itself, and there have been few to no concrete proposals for policy actions that could capture savings in this way.
Ultimately, the takeaway from all of this evidence should be one of real hope, mixed with caution. An incredibly robust body of research indicates that quality pre-k can have positive impacts on children's learning and lives, for kids at all income levels but particularly poor and at-risk children. At the same time, this research shows that all preschool is not created equal--implementation and design choices make a difference in the results produced for kids and the return on investment. And there are no free rides--if we want to provide kids with pre-k, we need to make the hard choices to find ways to pay for it. That means that any effort to expand children's access to quality pre-k in the U.S. has incredibly hard work ahead--but it's work that's well worth doing and has a deep evidence base to support it, not just about the benefits of pre-k, but also about how to do it well to get results.