Effects of New Jersey's Abbott preschool program on children's achievement, grade retention, and special education through tenth grade

Relatively few studies provide rigorous estimates of the long-term effects of large-scale public preschool programs, and their findings vary greatly. This study investigates the effects in third through tenth grade of New Jersey's Abbott preschool program which has many of the features and contexts hypothesized to mitigate fadeout. The program was designed and implemented in the context of a Court mandated systemic reform of education and its funding from preschool through high school. We describe in detail the program's features including an extensive, multitiered continuous improvement system. Sample size for analyses ranged from 426 to 785 depending on the grade and assessment. Participants were primarily Black and Hispanic students living in 31 communities with high concentrations of poverty. Inverse weighting by propensity scores was employed with multiple imputation for missing data to estimate effects on achievement, grade retention, and special education. Substantial positive effects were found in language arts and literacy, mathematics, and science on statewide assessments. Effects did not fade after grade 3. Achievement effects appear to be larger for 2-year than 1-year of the preschool program. Grade retention was significantly lower through grade 10. Effects on special education placement were imprecisely estimated but consistent with other findings of reduced special education. Results were robust with respect to alternative methods to control for measured and unmeasured differences between preschool and comparison groups and for missing data. This study adds to the evidence on preschool program features and contexts associated with long-term effects.