Cognitive and Noncognitive Peer Effects in Early Education
研究学前教育的同伴效应，发现同伴对数学和阅读成绩有显著正向影响，但对行为和社会结果影响不显著；同伴外化问题会阻碍认知发展，忽视这些效应会低估学前教育的回报。
We examine peer effects in early education by estimating value-added models with school fixed effects that control extensively for individual, family, peer, and teacher characteristics to account for the endogeneity of peer group formation. We find statistically significant and robust spillover effects from preschool on math and reading outcomes, but statistically insignificant effects on various behavioral and social outcomes. We also find that peer externalizing problems, which most likely capture classroom disturbance, hinder cognitive outcomes. Our estimates imply that ignoring spillover effects significantly understates the social returns to preschool. © 2010 The President and Fellows of Harvard College and the Massachusetts Institute of Technology.