基尼系数和中等收入群体比重的关联性分析

基尼系数是测量和判断收入分配状况最常用的综合指标之一,而中等收入群体比重则是判断社会稳定与否的重要标志。本文通过重新定义低、中、高三类收入群体以及采用多项式函数形式拟合洛伦兹曲线,建立基尼系数和中等收入群体比重之间的数量对应关系。实证分析表明:基尼系数和中等收入比重之间存在负向相关关系。2001年中国的基尼系数约为0．44,相应的中等收入群体比重大致在44%左右。

An Analysis on the Relationship between Gini Coefficient and the Proportion of Middle Income Group

Gini coefficient is one of the most popular and comprehensive indicators to estimate and judge income distribution while the proportion of middle income population is regarded as an important indicator to assess the social stability. The paper studies on the relationship between Gini coefficient and the proportion of middle income group by using a new definition of low, middle, and high income groups and simulating Lorenz curve in the form of polynomial function. The empirical study shows that there is a negative correlation between the Gini coefficient and the proportion of middle income group. The Gini coefficient in the PRC in 2001 was 0. 44 and the proportion of middle income population is about 44%.