中文摘要：

本文利用1991-2009年的CHNS数据使用分位数回归法及基于反事实分析的FFI。分解法分析非正规就业比重及非正规就业与正规就业的收入差距变动对城镇居民收入分配的影响。结果表明：第一阶段（1991-2000年），非正规就业的比重及与正规就业的收入差距的增加是城镇居民收入差距扩大的重要原因；第二阶段（2000-2009年），非正规就业比重的增加依旧引起收入差距的扩大，但两者之间收入差距的下降引起了收入差距的缩小，前者大于后者，造成第二阶段城镇居民收入差距的扩大。

英文摘要：

Based on the CHNS data from 1991 to 2009, this paper analyzes the effect of the proportion of informal employment and the changes in the rate of return on the informal employment on the income inequality of urban residents. This paper uses the quantile regression and the counter-factual FFL decomposition method to analyze this problem. The results show that. on the first stage, the increase of the proportion of informal employment and the relative high returns to informal sector widen the urban income inequality; on the second stage, the increase in the proportion of informal employment is still an important reason for the widenning income gap, and the decline of the returns in the informal employment narrow the income inequality. However, the effect of the former than the latter, which raised urban residents＇ income gap in the second phase.