基尼系数组群分解新方法研究:从城乡二亚组到多亚组

A New Decomposition of Gini-Coefficient by Population Subgroups

本文尝试在程永宏(2006)的基尼系数城乡分解方法基础上,论证一种适合多亚组的基尼系数组群分解新方法。主要内容是:第一,分析了现有分解方法不完善的原因;第二,推导出不含交叠项的多亚组情形下的分解方法,摆脱了交叠项的困扰;第三,提出一个组间不平等新指标并论证其理论依据;第四,明确解释了分解式和组间不平等新指标的社会福利含义。

This paper demonstrates a new decomposition of the Gini-coefficient under multi-subgroups, The main contents are as follows. First, the fundamental reasons of imperfections on present decomposition methods are analyzed. Second, a new decomposition of Gini-coefficient under multi-subgroup without overlap term is proposed. Third, the reliable theoretical basis and the clear economic significance of the between-group inequality index are proposed and proved. Lastly, the meaning of welfare economics behind the decomposition and the between-group inequality index are explored.