教育信号价值在公共部门更高吗?——基于文凭效应法的实证分析

Is the Signaling Value of Education Higher in the Public Sector?——An Empirical Study based on the Sheepskin Effects Method

基于2006-2013年的中国综合社会调查数据(CGSS),本文利用Heckman两阶段法和工具变量法纠正样本选择性偏差和内生性问题后,采用文凭效应法研究公共部门与非公共部门的教育信号价值差异。研究发现,第一,我国劳动力市场中存在显著的部门工资溢价,公共部门收入高于非公共部门收入;第二,各层次教育的信号价值存在显著的部门差异,非公共部门显著高于公共部门,在高等教育层次上更为明显;第三,分性别看,教育信号价值对非公共部门中的女性更为重要,而男性的教育信号价值并不存在明显的部门差异。研究结果揭示当前我国劳动力市场中工资决定机制的部门差异,为未来收入分配体系的调整提供了参考依据。

Based on the data from Chinese General Social Survey（CGSS） from 2006 to 2013, this paper analyzes the different effects of education signal value between public and non-public sectors by the sheepskin effect method, after adjusting the sampling self-selection bias and endogeneity of the variables through Heckman two-stage way and instrumental variables method. The research primarily finds that there exist significant sectors of wage premium in Chinese labor markets, and the wage in public sector is higher than non-public sector. Secondly, the signaling value in different levels of education displays differently in each sectors, and the non-public sector is significantly higher than public sector, particularly in higher education. Thirdly, the signaling value of education is more important to women in non-public sector, while the signaling value of education do not show obviously difference in sectors for men. The result indicates the sector differences of wage determination mechanism in current Chinese labor markets, which will offer evidences in decision-making of the ongoing income distribution system reform.