我国居民收入基尼系数的估计及城乡阶层效应——基于城镇、农村收入20分组数据的研究

The Estimation of Income Gini Coefficient in China and Its Stratification Effect:based on the new 20 grouped data of urban and rural

基于2013年调整的城镇、农村居民20分组收入数据,文章再估计了我国2005-2012年的城镇、农村及城乡混合的基尼系数,结果表明,我国总体基尼系数由2005年的0.4563下降到2012年的0.4293,城镇基尼系数有下降趋势,农村基尼系数较稳定;比较研究发现,以往基于未调整的农村分组数据的基尼系数估计会由于缺少大量高收入群体信息而高估了农村基尼系数,从而高估了总体基尼系数。而且,基于Yitzhaki(1994)的城乡分解框架,我们发现,城乡内部差距比城乡间差距对总体差距的贡献更大;城镇收入分布的阶层效应比农村的更强,即城镇群体更加趋向于形成一个阶层,而且我国的城乡阶层效应越来越明显。

Based on the new 20 grouped income data of urban and rural,wereestimate the gini coefficients of China from 2005 to 2012. Results show that the total gini are decreasing from 0. 4563 in2005 to 0. 4293 in 2012,and urban＇s gini have declining tendency while rural＇s gini are stable. We find that it will overestimate the rural＇s gini based on the past grouped data because of missing lots of information about highest income group,resulting in overestimation of the total gini. What＇s more,according to the decomposition of Yitzhaki（ 1994）,we find that the within group inequality is more important than between group inequality,and the urban＇s stratification effect is larger than rural＇s,i. e.,comparing to rural,urban is more stratified; what＇s more,the society becomes more stratified.