Gini coefficient

The Gini coefficient is a measure of inequality developed by the Italian statistician Corrado Gini and published in his 1912 paper "Variabilità e mutabilità". It is usually used to measure income inequality, but can be used to measure any form of uneven distribution. The Gini coefficient is a number between 0 and 1, where 0 corresponds with perfect equality (where everyone has the same income) and 1 corresponds with perfect inequality (where one person has all the income, and everyone else has zero income). The Gini index is the Gini coefficient expressed in percentage form, and is equal to the Gini coefficient multiplied by 100.

External links

• Measuring income inequality: a new database, with link to dataset
• UN Human Development Report 2004, p50-53: Gini Index calculated for all countries.
• http://oregonstate.edu/~crawfose/research_writing/SOC516--Final.doc Comparison of Urban and Rural Areas' Gini Coefficients Within States
• http://www.wider.unu.edu/wiid/wiid.htm World Income Inequality Database
• http://www.forbes.com/billionaires/free_forbes/2003/0317/098.html, Forbes Article, In praise of inequality
• Software:
• Free Online Calculator computes the Gini Coefficient, plots the Lorenz curve, and computes many other measures of concentration for any dataset
• Free Calculator: Online and downloadable scripts (Python and Lua) for Atkinson, Gini, Hoover and Kullback-Leibler inequalities
• Users of the R data analysis software can install the "ineq" package which allows for computation of a variety of inequality indices including Gini, Atkinson, Theil.