In this study, the authors examine the long-term impacts of publicly subsidized preschool and nurse home visitation in Denmark, using administrative data from preschools that began receiving public funding between 1930 and 1957.
Overall, they find that low-income Danish kids benefited from preschool access in several ways, and that some of those benefits were passed on to the next generation. However, for kids who also had nurse home visitation at birth, the positive effects of receiving pre-school were reduced by 80–90 percent. For example, Danish kids who had access preschool by age three were about 10 percent less likely to have only a compulsory education at age twenty-five—unless they also had nurse home visitation, in which case the impact of pre-school was only a fifth as large. Similarly, male students with access to preschool earned about 2 percent more as adults. However, those with nurse home visitation saw an earnings boost only a tenth as large.
This pattern suggests that preschool and nurse home visitation may have been substitutes rather than complements—at least in pre-World War II Denmark. However, the program’s design makes it difficult to know what to make of this finding.
To receive public funding, Danish preschools had to have staff with expertise on children, be open for at least four hours each working day, and provide services exclusively or predominantly to children from poor families. However, the Danish government also regulated and monitored preschools’ hygienic conditions and encouraged them to work with local physicians and dentists to monitor children’s health while reimbursing them for expenses related to these health check-ups. Thus, Danish preschools performed some of the same functions as the nurse home visitation program, in which trained nurses were assigned to visit newborns and their mothers approximately ten times during the first year of life so they could communicate the basics of infant care (“calmness, orderliness, and cleanliness”), monitor the babies’ development, and refer them to doctors if necessary.
Because of this overlap—that is, because Danish preschool had a modest public-health dimension—the meaning of the negative interaction between preschool and nurse home visitation is not so clear. Perhaps the benefits of early Danish preschools are primarily attributable to their public health dimension rather than their educational content. Or perhaps health and education interventions function as substitutes in the early years (at least when it comes to their long-term benefits).
Regardless of where the truth lies, the study raises important and under-examined questions about how preschool and other programs (like nurse home visitation) do or don’t interact, and whether the enrollment approach taken by current programs is as efficient as it might be.
As the authors observe, “In a world with limited public resources, it may be efficient to design programs that specifically target populations without prior exposure to other interventions. For instance, while many over-subscribed programs for low-income children allocate slots at random or on a ‘first-come, first-serve’ basis, our evidence suggests that an allocation mechanism that considers (the lack of) participation in earlier programs as potentially leading to greater program benefits.”
Given the billions of dollars the U.S. already spends on (potentially overlapping) programs like Head Start and Early Head Start, the continuing debate over whether (and for whom) they are effective, and the ongoing push for universal pre-K, this study’s hypothesis is worth testing. Unfortunately, it will probably be awhile before it is rejected or confirmed.
SOURCE: Maya Rossin-Slater and Miriam Wüst, "What is the Added Value of Preschool? Long-term Impacts and Interactions with a Health Intervention," NBER (September 2016).
