继续狂欢：青少年期社会网络的劳动力市场回报

中文摘要

我们利用“全国青少年至成人健康纵向研究”的数据，考察青少年期友谊对成年后收入的回报。由于教育与友谊在青少年期是共同决定的，对两者回报的普通最小二乘（OLS）估计很可能存在偏误。我们采用一种新程序来确定友谊因果回报的界限：基于既有文献，假设教育回报介于5%至15%之间，并以同伴之间年龄的相似程度作为友谊的工具变量。青少年期每多一个朋友，收入就会增加7%至14%，这一增幅大幅高于OLS估计所暗示的水平。

Abstract

We investigate the returns to adolescent friendships on earnings in adulthood using data from the National Longitudinal Study of Adolescent to Adult Health. Because both education and friendships are jointly determined in adolescence, OLS estimates of their returns are likely biased. We implement a novel procedure to obtain bounds on the causal returns to friendships: we assume that the returns to schooling range from 5 to 15% (based on prior literature), and instrument for friendships using similarity in age among peers. Having one more friend in adolescence increases earnings between 7 and 14%, substantially more than OLS estimates would suggest.