大学生非正规就业及其对收入不平等的影响研究

After the start of higher education expansion in 1999, there is a rapid rise of supply of college graduates. Meanwhile, the informal employment begins to take larger share of new labor market positions, which leads more and more college graduates fall into informal employment. In this project, based on micro-level survey data and the methodology of labor economics and econometrics, we will (1) estimate the size and the trend of informal employment of college graduates after the higher education expansion; (2) investigate four categories of factors that will affect the choice of employment of college graduates, meanwhile decide whether the group of informal employed college graduates are homogenous or heterogeneous compared to other informal employed workers; (3) decompose the income difference between formally employed and informally college graduates by quantile regression and the counter-factual prediction methodology, and use cohort study to analyze the dynamic effects of informal employment on income inequality among college graduates; (4) investigate the effects of informal employment on inter-generational income inequality and mobility for college graduates.This project is a good attempt trying to analyze the newly emerging employment of college graduates with reliable empirical studies, and it has practical implications as well as academic importance.

高校毕业生人数增加、正规部门新增就业不足和非正规就业的快速发展，使得大学生选择非正规就业的比重越来越高，国内外现有的研究较少对大学生非正规就业这种新的就业选择行为及其影响进行研究。本项目在现有研究基础上，运用微观调研数据和劳动经济学、计量经济学的相关理论和方法，首先，考察高校扩招以来大学生非正规就业的规模及其变动，进而分析影响大学生非正规就业的个人特征因素、家庭经济社会地位、高校特征和劳动力市场政策分别对大学生非正规就业选择的影响，其次，在不同收入分位数上利用反事实的分解方法考察影响非正规就业对大学生收入差距的影响，进而在考虑样本异质性基础上，利用Cohort分析的方法分析大学生非正规就业对其长期收入不平等的影响，最后考察大学生非正规就业如何影响代际之间的收入不平等。本研究基于我国劳动力市场发展面临的新问题而提出，全面系统的考察这一问题对完善大学生就业的相关政策具有重要意义。

我国劳动力市场非正规就业异质性显著，既包括以大学生为主体的技能劳动力，也包括以农民工为主题的低技能劳动力。本项目从教育和劳动合同两个维度对非正规就业的异质性进行考察。大学毕业生内部的异质性也非常强，从收入差异看，正规自雇者高于非正规自雇者，高于正规工资获得者，高于非正规工资获得者；从就业流动性来看，非正规工资获得者超过四分之三实现了向更高收入就业类型的流动；非正规自我雇佣者绝大多数要么维持非正规自我雇佣要么流向正规就业。劳动合同的角度来看，不同雇佣合约类型造成了劳动力市场的分割，期限越长越稳定的雇佣合约导致的劳动力市场分割的程度越高，市场分割程度还通常与收入水平呈正向关系。采用《劳动合同法》分析法律实施对农民工劳动关系以及社保覆盖的影响，发现法律的施行提高了农民工的书面合同签订率，这进一步提升了农民工的社保覆盖率，降低了拖欠农民工工资的发生率。