One year of preschool or two: Is it important for adult outcomes?

Until the last year, public funding for preschool education had been growing rapidly over a decade with most state programs providing one year of preschool for four year olds. Fewer three year olds are enrolled in preschool. To investigate the importance of enrollment duration, this study is the first to estimate long-term dosage effects of years of preschool. We use data from a cohort of 1,500 students in the Chicago Longitudinal Study who...