中文摘要：

基尼系数的子群分解公式有多种形式，不同分解公式的实证结论有较大差异。本文分析了群内基尼系数的权数以及群间不平等指标所应具备的基尼系数内涵，提出了一个新的群间不平等指标，从而给出了一个新的基尼系数子群分解公式。利用这个新的基尼系数子群分解公式，本文实证分析了近年来中国总体基尼系数的城乡分解。实证结果表明，农村群间不平等对总体基尼系数的贡献率最大，城镇群内不平等的贡献率不断上升，这是促使中国总体基尼系数不断上升的两个重要因素。

英文摘要：

There are many approaches to subgroup decomposition of the Gini coefficient, and empirical studies based on different approaches lead to different conclusions. This paper studies the weights of subgroups and the Gini type intergroup inequality, and presents a new subgroup decomposition formula. We also study the overall Gini coefficient in China. The empirical results show that the major contributor to China＇s overall Gini coefficient is intergroup inequality between rural and urban residents, and the contribution of within-urban inequality is rising.