There鈥檚 a lot to like about preschool. Over the years, my kids have used several different preschools鈥攆rom a cheerful church basement to a hard-core Montessori鈥攁nd had a number of really positive experiences. You don鈥檛 need to convince me that good, affordable, reliable, and convenient preschool is something we should value.
But it鈥檚 a big leap from there to concluding that preschool 鈥渨orks鈥� or that universal pre-K is a good idea. Now, when I offer such qualifications, preschool aficionados immediately leap to patiently (or not-so-patiently) explain that I鈥檓 ignoring the science.
As for that science. Earlier this year, researchers at Vanderbilt University released the outcomes of a new gold-standard study of Tennessee鈥檚 statewide pre-K program, launched back in 2009. The study has been as the only randomized 鈥渢horough, ongoing investigation into the impacts of a statewide pre-K program for economically disadvantaged children.鈥� The findings of the initial 2015 report were regarded as highly , with the benefits of the pre-K program fading before 1st grade. The follow-up results any better. The pre-K students fared worse on state assessments than their peers and had worse outcomes 鈥渇or disciplinary infractions, attendance, and receipt of special education services.鈥�
Readers who regularly hear that pre-K 鈥渨orks鈥� might be surprised. They shouldn鈥檛 be. The truth is, an analysis of the 10 best-known, widely cited pre-K programs that the research around these programs shows not 鈥渢hat 鈥榩re-K works鈥欌�� but that 鈥渟ome early childhood programs yield particular outcomes, sometimes, for some children.鈥� Indeed, the most credible research has made clear that 鈥渢he most meaningful, far-reaching effects鈥� are the product of 鈥渃arefully designed, well-implemented programs鈥濃�攏ot sweeping mandates.
And even the studies that do indicate pre-K efforts were beneficial don鈥檛 necessarily point at a clear path forward for policies on pre-K. Consider the famed , a small pilot preschool and home-visiting program for 3- and 4-year-olds that ran from 1962 to 1967 in Ypsilanti, Michigan. The program provided 58 low-income Black children with two years of a research-based preschool curriculum and weekly home visits. It was found to have positive impacts on participants鈥� educational and life outcomes, reducing teenage pregnancy, and increasing lifetime earnings. All good stuff. But we鈥檙e talking about less than 60 students, in an intensive boutique pilot program, more than a half-century ago. The notion that Perry offers a clear blueprint for broad public policies is just fantastic.
And yet, some years back, Nobel Prize-winning economist James Heckman savaged a newspaper columnist for even questioning the benefits of expanded pre-K. Heckman insisted that it clearly works. How did he know this? Heckman pointed to his 鈥渆vidence-based analysis of more than 30 years of data鈥� from the Perry Preschool project. 鈥淚t is as good a trial for effectiveness as those we currently rely on to evaluate prescription and over-the-counter drugs,鈥� he .
While Heckman is a very smart guy, he was wrong here. There鈥檚 a difference between a medical therapeutic and a public-policy response. Unlike a preschool program, the ingredients of an over-the-counter drug can be replicated exactly and administered to new patients with precise directions. In the case of Perry, it鈥檚 not especially clear just what it means to replicate the program. Was the intervention simply attending a preschool? Doubtful. Was it attending a 鈥渉igh quality鈥� preschool? OK, but just what made Perry 鈥渉igh quality鈥�? Was it the student-teacher ratio? Home visits? The curriculum? All of the above? How exactly does one know?
Unless we know, it鈥檚 tough to be confident that policies will deliver the desired results. Worse, the bigger the policy, the bigger the risk that getting things wrong will have adverse consequences. And yet much of the support for universal preschool proceeds with a blind assurance that leaves all such difficult questions aside. For instance, last fall, the Biden administration鈥檚 Build Back Better proposal for universal preschool contained sweeping new federal that would鈥檝e governed preschool education standards, credentials, and pay. There was little evidence behind any of this and actually more cause to fear the ways in which it might bureaucratize early-childhood education, squelch small church-based and neighborhood providers, drive up costs, and aggravate staffing challenges. We would鈥檝e been far better served not by assertions of 鈥渢he science says鈥� but by serious discussions of uncertainty, trade-offs, and sensible compromise.
Helping ensure that families have access to reliable, trusted child-care options is a good idea. But the claims made about preschool鈥攁nd especially about universal pre-K鈥攖end to be overstated, the benefits are far from certain, and fail to consider that massive new programs can cause real harm. We should keep working to expand access to reliable, convenient, trusted preschool. But we should do so guided by good judgment, not by overreliance on not-so-certain science.
