方法对比

	Gini Coefficient	Palma Ratio
领域	Sociology	Sociology
方法族	Process / pipeline	Process / pipeline
起源年份	1912	2011 (Palma's finding); 2013–2014 (the ratio)
提出者	Corrado Gini	Gabriel Palma; named by Cobham & Sumner
类型	Scalar measure of statistical dispersion / inequality	Tail-ratio inequality measure
开创性文献	Ceriani, L., & Verme, P. (2012). The origins of the Gini index: extracts from Variabilità e Mutabilità (1912) by Corrado Gini. The Journal of Economic Inequality, 10(3), 421–443.	Cobham, A., & Sumner, A. (2014). Is inequality all about the tails? The Palma measure of income inequality. Significance, 11(1), 10–13.
别名	Gini index, Gini ratio, Gini concentration ratio, G	Palma index, Palma measure, top10/bottom40 ratio
相关	5	5
摘要	The Gini coefficient is the most widely used single-number summary of inequality in a distribution such as income or wealth. Introduced by the Italian statistician Corrado Gini in 1912, it equals twice the area between the Lorenz curve and the line of perfect equality, ranging from 0 when everyone has the same amount to a maximum approaching 1 when one unit holds everything.	The Palma ratio measures income inequality as the ratio of the income share held by the richest 10 percent of the population to the share held by the poorest 40 percent. It rests on the empirical regularity, documented by Gabriel Palma, that the middle deciles (5 through 9) capture a remarkably stable half of national income across countries, so that inequality is essentially a contest between the top and the bottom — the 'tails' of the distribution.