Recently published research on the community-level effects of pre-K (More at Four) and child care (Smart Start) in North Carolina finds that both programs led to increases in reading and math scores in third grade.
- North Carolina third graders had higher reading and math scores in counties that had received more funding for Smart Start and More at Four when the children were younger.
- The estimated effects of Smart Start and More at Four investments were equal to test score gains of about four months of third grade reading instruction and two months of math instruction. Notably, these results are for all children in the community, not just children who participated in either early childhood program.
- While the authors did not do a full benefit-cost analysis, they note that the benefits in math and reading gains outweighed the program costs. The expected savings from reduced instructional costs for children whose community received Smart Start or More at Four funding was at least equal to the cost of those programs.
Community-level effects – the concept of spillover: One really interesting aspect of this study was that the researchers assessed the outcomes of children at the county level, including children who participated in the preschool or the child care initiative as well as children who did not. The authors note that this approach 
allows them to measure the potential spillover effects of the program; that is, children living in the county but not participating in the program may also be affected indirectly, by other students’ participation in the program. In theory, spillover could be positive or negative. Positive spillover effects could occur in the elementary school classroom, for example, with a larger proportion of classmates arriving at elementary school ready to learn, enhancing the learning environment in that classroom.
More study details: The article by Duke University researchers Helen Ladd, Clara Muschkin, and Kenneth Dodge and published in the Winter 2014 issue of the Journal of Policy Analysis and Management, examined the effects of two North Carolina early education initiatives: Smart Start, the comprehensive child care and community services initiative, and More at Four, the state-funded preschool initiative. The study used county-level program spending data matched with children’s birth records for children born between 1988 and 2000 and their third grade test scores to look at changes in test scores that took place after the introduction of More At Four and Smart Start in those counties. The differences in when counties invested in these initiatives across the state allowed the researchers to assess the impact of More At Four and Smart Start on children’s math and reading performance. To address other potential differences over time in counties which could also affect children’s math and reading scores, the researchers included statistical controls for related variables, a common and appropriate technique.
The numbers behind the basic benefit-cost results reported in the study were: math and reading test score gains of two to four months translate into cost savings of $1,700 and $3,400 per child in the community (based on per-month costs out of a 10-month school year, which was $8,500 per child in North Carolina). This was compared to program costs for More at Four and Smart Start of $1,100 per child in the community for each program.
Another benefit of measuring community-wide effects is that the authors were able to avoid a common potential problem in research studies that do not randomly assign people: selection bias. Selection bias is the potential bias that is created in a study based on how participants are chosen, such as when people self-select into the “treatment” being studied. In this case, the treatment is preschool or child care, and the children whose parents sent them to public preschool may be different in meaningful ways (such as child health, family income, or parent education level, to name a few) than the children whose parents did not send them to preschool. The differences observed between kids in preschool and those not in preschool may be due to preexisting differences between those groups of kids, rather than due to the experience of preschool itself. Since this study examines outcomes for all children in the county, those participating and not participating in the preschool and child care initiatives studied, the researchers avoided this self-selection problem.
Child Policy Developments 