Language Skills and Earnings: Evidence from Childhood Immigrants*
利用儿童比成人更容易学习语言的现象，构建工具变量，发现童年移民美国的成人英语水平显著提高工资，且该效应主要通过教育传导。
Research on the effect of language skills on earnings is complicated by the endogeneity of language skills. This study exploits the phenomenon that younger children learn languages more easily than older children to construct an instrumental variable for language proficiency. We find a significant positive effect of English proficiency on wages among adults who immigrated to the United States as children. Much of this effect appears to be mediated through education. Differences between non-English-speaking origin countries and English-speaking ones that might make immigrants from the latter a poor control group for nonlanguage age-at-arrival effects do not appear to drive these findings. © 2004 President and Fellows of Harvard College and the Massachusetts Institute of Technology.