Neighborhood Spillover Effects of Early Childhood Interventions

This study explores the role of neighborhoods on human capital formation at an early age. We do so by estimating the spillover effects of an early childhood intervention on the educational attainment of a large sample of disadvantaged children in the United States. We document large spillover effects on the cognitive skills of children living near treated children, which amount to approximately 40\% of the direct treatment effects. Interestingly, these spillover effects are localized and decrease with the spatial distance to treated neighbors. We do not find evidence of spillover effects on non-cognitive skills. Perhaps our most novel insight is the underlying mechanisms at work: the spillover effect on cognitive scores is very localized and seems to operate through the child's social network, mostly between treated kids. We do not find evidence that parents' or children's social networks are effective for non-cognitive skills. Overall, our results reveal the importance of public programs and neighborhoods on human capital formation at an early age, highlighting that human capital accumulation is fundamentally a social activity.