基尼系数理论最佳值及其简易计算公式研究

本文针对《中国统计年鉴》有关城镇和农村居民收入数据单列而难以直接测算城乡合一基尼系数的情况 ,证明了 :在收入五分法下基尼系数的计算方法 ,可以五分法中最高收入组与最低收入组各自所占的收入比重之差来简易计算。文章以严格的数学推导证明出基尼系数的理论最佳值为三分之一 ,并用推导出的简易公式对世界银行利用收入五分法所公布的 3 2个国家的统计数据进行了重新计算 ,结果发现 ,以笔者的简易公式所计算出的基尼系数与世界银行公布的基尼系数极其接近。本文关于基尼系数的简易计算公式及其理论最佳值的分析 ,为中国城乡合一的基尼系数的测算及分析提供了一种新的思路。

A Study of the Best Theoretical Value of Gini Coefficient and Its Concise Calculation Formula

The paper pointed out the difficulty of calculating China's Gini coefficient because the income distribution data in the “China Statistics Yearbook”is given separately under the title of “Urban” and “rural”. The paper got a concise formula for calculating Gini coefficient: Gini Coefficient equals the difference between the income percentage of the highest income group and the income percentage of the lowest income group in the quinquepartite income. The paper proved with strict mathematics that the best theoretical value of Gini coefficient is 0.3333,or a third. The paper calculated Gini coefficient of 32 countries by using the concise formula and the data published by the World Bank. A comparison between the calculated Gini coefficients and the published Gini coefficients by the World Bank shows that the results are very close to each other. The analysis of the best theoretical value and the concise calculation formula of Gini coefficient in the paper provided a simple and quick way to calculate Gini coefficient of China as a whole.