高等教育的文凭效应及其异质性——基于中国综合社会调查数据的实证分析

Diploma Effect of Higher Education and Its Heterogeneity:Empirical Analysis Based on CGSS Data

基于中国综合社会调查数据,利用“文凭效应法”实证研究我国高等教育的文凭效应及其在不同世代和收入群体中的异质性。研究发现:(1)高等教育文凭显著正向影响收入,能给个体带来39.65%的额外收入,我国劳动力市场中存在高等教育文凭效应。(2)高等教育文凭对个体收入的贡献存在部分世代异质性,以60后为参照组,70后、80后的高等教育文凭效应分别降低了4.11%、3.92%,但并不显著,90后的高等教育文凭效应显著降低21.26%。(3)在收入异质性方面,高等教育文凭效应呈现出“先缓慢增加,后微幅下降,再迅速增加”的趋势,高等教育文凭的信号价值在高收入群体中体现得更为明显。文凭效应对收入的异质性影响不再表现为教育收益率的“U型”趋势,也从侧面反映出教育与收入二者关系的复杂性。

Based on the comprehensive social survey data in China,the“diploma effect method”is used to empirically study the diploma effect of higher education in China and its heterogeneity in different generations and income groups.The study found that:(1)Higher education diploma significantly positive impact income,can bring 39.65%of the additional income to individuals,there is a higher education diploma effect in the labor market.(2)The contribution of higher education diplomas to individual income has some generational heterogeneity,taking the post-60s as a reference group,the post-70s and post-80s higher education diploma effects were reduced by 4.11%and 3.92%respectively,but they were not significant,and the post-90s higher education diploma effects were significantly reduced by 21.26%.(3)In terms of income heterogeneity,the effect of higher education diplomas shows a trend of“first slowly increasing,then slightly decreasing,and then increasing rapidly”,and the signal value of higher education diplomas is more obvious in high-income groups.The heterogeneous impact of the diploma effect on income is no longer manifested as an“U-shape”trend in the rate of return on education,and also reflects the complexity of the relationship between education and income.