中国的收入机会不平等——基于2013年中国家庭收入调查数据的研究

Inequality of Income Opportunity in China:Evidence from the 2013 CHIP Data

中国当前的收入不平等问题饱受质疑。影响收入不平等的因素中,既有自身不能控制的环境因素,也有个人努力因素。根据Roemer(1998)的研究,如果人们的收入与环境因素无关则意味着机会平等;反之,如果收入与环境因素相关,则意味着机会不平等。本文基于机会公平理论框架,将影响收入的变量分为环境和努力两类,通过随机占优方法检验机会不平等的存在性,并用参数方法衡量中国的收入机会不平等,分析结果不平等中机会不平等所占的比例。结果发现:2013年中国收入机会不平等指数约为0.10,环境造成的机会不平等约占结果不平等的1/5;夏普里分解得知,家庭收入和出生地是造成收入不平等的最主要因素;分位回归结果表明,中等收入群体的收入机会更加不平等。

Income inequality has become a serious social problem in China.Two groups of factors are found to affect inequality.One includes‘circumstances’factors,in which individuals are embedded and generally have little control;and the other includes‘personal’factors which individual could change through personal efforts.According to Roemer(1998),equality of opportunity implies outcomes are uncorrelated with social circumstances,while a correlation between the two suggests inequality of opportunities.Under this theoretical framework,this paper tests the existence of inequality of income opportunity with a stochastic dominance method and estimates the inequality level using parametric methods.The result shows that the index of inequality of income opportunity was 0.10 in 2013,and about 1/5 of inequality of outcomes could be attributed to inequality of opportunity in China.A further Shapley decomposition suggests that family income and place of birth are two most important factors leading to inequality in opportunities.Results of quantile regression shows that the inequality of income opportunity is more serious among the middle-income group.