身份差别与收入差距：基于分位数回归的实证研究

基于均值分析的经典OLS回归掩盖了身份变量对于不同收入点的作用大小和显著性,本研究引入分位数回归,重点分析身份差别对于收入分布的影响及影响的规律性。利用2013年家庭住户收入调查（CHIP）数据,研究发现：①户籍身份对收入的条件分布具有呈"U"形的显著影响。②党员身份对中高端收入人群具有扩大收入差距的效应。③就业身份的影响差异明显,固定职工、长期合同人员相对于临时合同、没有合同人员在收入分布的中高端具有显著且更大的影响;在任一收入分位数水平上,固定职工、长期合同、临时或短期合同、没有合同的收入回报依次降低。

Difference in Identity and Gap in Income: an Empirical Research based on Quantile Regression Analysis

There are multiple identities such as household registration status(hukou identity),political identity,employment status for individuals in Chinese society.However,the current literatures on the relationship between identity and income neglected how identity effects on income distribution.The traditional OLS regress methods based on the analysis of the mean value cannot reveal the different effects of identity on income distribution.Therefore,this research introduces quantile regression to analyze the effect of identity on income distribution and to explore whether there is a common regularity for the effects.Using the 2013 household income survey(CHIP)data,the study finds that:(1)the household registration has a u-shaped and statistically significant effect on individual income,which suggests that the household registration widens the income gap at both the low-end and high-end.(2)The political identity of being a party member has a greater and significant influence at the high-end,suggesting that political identity widens the income gap at the high-end of income distribution.(3)The influence of employment status differentiates.The employers consistently have a higher return than the employees with an increasing regression coefficients.Working with a fixed-term employment contract and long-term contract is more advantageous than person with a temporary contract or "without any the contract".At any given quantile level of the income distribution,people with a fixed-term employment earn a better income than the long-term contracts,and the latter excel those people with a temporary or short-term contract.(4)From the point of control variables,such as age,education,gender and unit types,etc.,most of them have an significant effects on income distribution as the theory may expect.Employers' income is obviously higher than that of employees,which embodies the return of the entrepreneurship.Foreign companies and the private sector relative to the state-owned enterprises,collective enterprises,whose marketization degree are higher,enjoys a greater return.The paper proposes that the government accelerate the reformation of the household registration system so as to attack the job segregation and to endow the agricultural people with equal employment rights and interests,thereafter narrow down the income gap for the low-income groups.And it also suggests to optimize the administrative system and to correct the distortion between the economic power and political power in order to eliminate the negative impact of the political status,and narrow the income gap for people within the high-income group.