In the overview essay, "Starting Early: Introducing the Issue," Jeanne Brooks-Gunn, Lisa Markman-Pithers, and Cecilia Elena Rouse offer a fair-minded overview. They write: "[W]e believe the weight of the evidence, as reflected in the articles in this issue, indicates that high-quality pre-K programs can indeed play an important role in improving later outcomes, particularly for children from more disadvantaged families. At the same time, significant questions remain."
Discussions of early childhood education often starts out with iconic programs like the Perry Preschool Program and the Abecedarian program. Both chose a group of children and provided services randomly to about half the group. Both had long-term follow-up into adulthood. Both found substantial gains in both academic and broader life outcomes. And frankly, I'm not sure that either one is especially relevant to the practical challenges and questions that early childhood education faces today.
The Perry Preschool Program in the Ypsilanti, Michigan, had a sample size of 123 students, of whom about half receiving services , from 1962-67. The Carolina Abecedarian program in Chapel Hill, North Carolina, inclueed 111 total students, of whom a randomly selected half received services. beween 1972 and 1982. These are high quality studies, well-designed and with excellent follow-up. They were also done four or five decades ago. The sample sizes were small. The assistance was intensive: for example the Perry Program included half-day day care and weekly home visits for 30 weeks per year, while the Abecedarian program was full-time day care for 50 weeks per year. The parents were quite disadvantaged in terms of being low income and low education (which in the mid-1960s in particular was before Medicaid and even widespread kindergarten). The alternative early enrichment options for children from disadvantaged families back at this time were much less available than in more recent years.
The practical difficulty is that extrapolating these kinds of small-scale pilot program with a few dozen students up to to a city-wide programs, much less up to statewide or national programs, is an enormous leap, and the results have not always been encouraging. For example, I wrote a few years back that "Head Start is Failing Its Test" (January 29, 2013). Starting in 2002, a nationally representative sample of 5,000 students was randomly assigned to Head Start, or not. The study found that academic effects of being assigned had faded out by third grade, and there were also no meaningful effects in "cognitive, social-emotional, health and parenting practices."
A more recent discouragement comes from a study in Tennessee, which Ron Haskins and Jeanne Brooks-Gunn discuss "Trouble in the Land of Early Childhood Education?" (Future of Children Policy Brief, Fall 2016). They write; "A recent evaluation has roiled the field of early childhood education with the finding that by the time they reached third grade, children who participated in Tennessee’s statewide pre-K program had worse attitudes toward school and poorer work habits than children who didn’t." Of course, when the Tennessee study showed positive results of pre-K in kindergarten, it was hailed as a high-quality program and a well-designed study, but when it showed undesirable results by third grade, it was then criticized as a low-quality program and a poorly designed study. But the
Other more recent studies in places like Tulsa, Oklahoma, and Boston, Massachusetts, have found more positive results. In the overview essay in the Future of Children issue, here's how Brooks-Gunn, Markman-Pithers, and Rouse describe the overall evidence:
At the end of most evaluated [early childhood education] programs, researchers find effects on school achievement, though these effects diminish over elementary school. When program effects are large, they tend to be maintained into elementary school, though they are smaller than the initial impacts. At the same time, we see long-term effects on adult outcomes—for example, a reduction in crime or the completion of more schooling. It’s puzzling that during elementary school, the achievement-test scores of children who attended prekindergarten converge with the test scores of children who did not, a phenomenon commonly called fadeout. Studies document that those who participate in a pre-K program have a significant advantage in kindergarten in terms of educational achievement. But those assigned to the control group tend to catch up in the first through third grades; in most evaluations, more than half the difference between the two groups disappears by the end of first grade.This conclusion is similar to that reached by Greg J. Duncan and Katherine Magnuson offer a broader and modestly more hopeful angle in their paper, "Investing in Preschool Programs," in the Spring 2013 issue of the Journal of Economic Perspectives. I offered some discussion of their findings
in "Preschool for At-Risk Children, Yes; Universal Preschool, Maybe Not" (May 23, 2013).
This kind of finding is why Brooks-Gunn, Markman-Pithers, and Rouse refer to significant questions that remain to be answered. Why do the academic effects of early childhood education so often fade out? Is it lack of lack of follow-up in schools? The importance of peer effects as student who received pre-K assistance are blended in later grades with those who do not? Maybe the pre-K programs themselves vary in some way? Maybe the benefits of such programs are non-cognitive--but noncognitive skills can be quite important. Here are some of their thoughts about ongoing issues.
Perhaps the problem is too much focus in pre-K programs on "constrained" skills, where "constrained skills (such as phonemic awareness and letter knowledge) and unconstrained skills (such as knowledge of the world). Young children are typically taught constrained skills, which are associated with success until second or third grade. Beyond third grade, however, mastery of comprehension is associated much more with unconstrained skills."
Perhaps there should be more explicit emphasis on noncognitive skills like executive function: "Executive function includes such abilities as attention, working memory, and inhibitory control— all of which are associated with cognitive and behavioral outcomes for both children and adults. Raver and Blair offer research to show that the development of executive function before children enter elementary school predicts their early math and reading skills. The authors also review promising individual and classroom interventions to improve executive function. Research on how to integrate the learning of memory, attention, and planning into the classroom is just beginning ..."
Perhaps some of the issue involves the qualifications and pay of pre-K teachers: "The proportion of pre-K teachers who have a bachelor’s degree and certification for teaching early childhood education has increased over the past 15 years. Still, far fewer pre-K teachers than kindergarten teachers are college graduates, owing to differences in requirements. State and city pre-K programs usually require teachers to hold a bachelor’s degree, which has led to disparities between pre-K teachers in programs administered by public school systems and those in Head Start and community programs. Wage differentials are also high. Indeed, many pre-K teachers experience financial hardship and lack health insurance. ... Until we pay more attention to the links between training and classroom interactions, we can’t evaluate the efficacy of current training and education programs. The same is true for implementing curricula in the classroom."
Perhaps some of the issue is the extent to which parental involvement is encouraged: "One of the goals of Head Start and other pre-K programs is to provide support, information, and even instruction to parents in the context of prekindergarten. In fact, being in favor of involving parents in their children’s pre-K programs seems much like supporting motherhood and apple pie. But even though everyone believes such involvement is necessary, we know little about whether it makes the programs more effective. In fact, Katherine Magnuson and Holly Schindler report that when parenting programs attached to pre-K programs have been evaluated, many have proven to be ineffective. But programs that target specific competencies are more likely to have benefits, especially those that help parents deal with their children’s behavior problems. Also, a few programs targeting mothers’ literacy and reading have been effective."
The promise of early childhood education focused on the most disadvantaged children is real. There are dozens of studies that have found positive effects. But the practical problem of designing and implementing programs to work at larger scale are also very real. As Brooks-Gunn, Markman-Pithers, and Rouse note: " We also need a better understanding of how to take high-quality programs to scale—the most relevant example being the rollout of city- and state-level pre-K programs."