谁从高等教育扩招中获益更多?——基于广义罗伊模型的实证证据

Who Benefits More from Higher Education Expansion? Evidence Based on General Roy Model

教育回报是个人以及社会最优教育决定的重要组成部分,传统的估计方法如工具变量法、回归断点设计和双胞胎设计等主要都是为了解决教育的内生性问题。然而,当教育回报存在根本的异质性,即教育回报与教育选择本身相关时,传统的估计方法便无法刻画这种不可观测的异质性。本文利用广义罗伊模型估计了大学教育的边际处理效应(MTE),研究证实,中国大学教育的回报率与大学教育选择之间存在相关关系。半参数局部工具变量(LIV)估计结果表明,随着个人大学选择的心理成本增加,大学教育的MTE单调增加。本文的研究结论表明,大学教育回报越低的人,越是倾向于选择接受大学教育。这种逆向选择模式主要由无法观测的家庭背景特征所导致:家庭背景越差的个人接受大学教育的心理成本越高,但是一旦上了大学,其回报率越高。

Estimating returns to education is an essential part of determining optimal schooling decisions, both at individual and social level. In the past, a lot of literatures have estimated returns to education. Traditional methods such as instrumental variable method, regression discontinuity design and twin design are mainly used to solve the endogeneity problem of education. However, there is essential heterogeneity in returns to education, that is, returns to education is correlated with selection of education, and traditional methods can t estimate such unobservable heterogeneity. Using research framework of Heckman & Vytlacil(2005,2007), this paper estimates the marginal treatment of college education based on general Roy model. The result of this paper proves the correlation between returns to college education and college selection. According to semi-parametric local instrumental invariable (LIV) estimation, the results show that the MTE of college education increases monotonously with the increases of psychological cost of going to college. This paper finds that individuals with lower benefits are more likely to select college education.This pattern of reverse selection on gains is driven by unobservable family background. Individuals with disadvantaged backgrounds have higher psychological cost of receiving higher education, however, once they have, they benefit more from higher education.