高校扩招政策降低了城镇劳动力的大学教育溢价吗？——基于反事实选择的因果关系推断

Does the Policy of Enrollment Expansion Reduce the University Education Premium of Urban Labor Force?——Based on Causal Inference of Counterfactual Choice

本文采用北京师范大学收入分配研究院提供的两轮收入调查数据,采用微观计量实证研究方法,基于教育选择的反事实选择框架,揭示了高校扩招政策与城镇劳动力大学教育溢价间的因果关系。结果发现:通过基准回归估算出整体教育回报率由2007年的7.1%上升到2013年的9.1%,分教育层级回归揭示了大学教育收益率在扩招政策前后均高于高中教育阶段,但在利用工具变量法纠正了内生性偏估后,城镇劳动力的整体教育回报率由14.1%下降到了9.1%,而纠正了自选择偏差后,整体教育回报率则由2007年的5%上升到了2013年的10.7%;利用倾向得分匹配法实现数据平衡后,通过平均处理效应估算出大学教育的年收益率由2007年的9.5%~9.75%上升到了2013年的11.425%~11.925%,验证了扩招政策并未降低城镇劳动力的大学教育溢价。基于此,本文提出,通过人力资本梯度升级至研究生教育层级,逐渐收敛由市场因素与人力资本因素引致的城镇收入不平等。

This paper,based on the CHIP data provided by the survey on income of residents in China,employs micro measurement empirical research methods and establishes the counterfactual framework to discuss the causality relationship between enrollment expansion policy and education premium of urban labor force.It is indicated that the total estimated rate of return to education increased from 7.1%in 2007 to 9.1%in 2013 by using OLS.The hierarchical regression shows that the rate of return to college education is higher than that of senior high school education.The total rate of return to education for urban labor force decreased from 14.1%to 9.1%by using instrumental variable method to correct endogenous bias;after correcting the selection bias in the labor market,the total rate of return to education increased from 5%to 10.7%.Using the propensity score method to achieve data balance,it is estimated that the annual rate of return to university education increased from 9.5%~9.75%in 2007 to 11.425%~11.925%in 2013 through ATT,indicating that the enrollment expansion policy did not reduce the university education premium of urban labor force.