Abstract: Does the individual income tax have the function of regulating the income gap as the important policy tool for regulating the income distribution in China? On this proposition the existing literature lack of comprehensive practical demonstration. This paper chooses the average tax rate progressivity and pre-tax and after-tax Gini coefficient as measure index, using the survey data of urban residents, to demonstrate the income distribution effect of the individual income tax from the structure and overall view. Through empirical analysis the author find three truths. First, the average tax rate of the individual income is progressive among the different income groups. Second, urban residents Gini coefficient of after-tax individual income is less than the pre-tax Gini coefficient, thus the individual income tax narrows the income gap. Third, the income distribution Effect of the individual income tax is different in different periods.

摘要： 个人所得税作为调节收入再分配的重要政策工具，起到了缩小居民收入差距的作用吗？现有的文献对该命题缺乏较为全面的实际论证。本文选择平均税率累进性和税前税后基尼系数作为衡量指标，利用城镇居民调查数据，从结构与整体视角论证了个人所得税的收入再分配效应。通过实证分析发现：第一，个人所得税的平均税率具有累进性，其具有调节居民收入差距作用；第二，征收个人所得税使基尼系数减小，体现其较强的收入再分配效应；第三，个人所得税的收入再分配效应因不同时期而存在差异。