Gini coefficient
The Gini coefficient (also known as the Gini index or Gini ratio) is a measure of differences in income. It was developed by the Italian statistician Corrado Gini in 1912.
Definition
The Gini coefficient is usually a number between 0 and 1 (or 0 to 100). 0 means a country where the income is equally distributed. On the other hand, 1 means that one person owns everything but the rest owns nothing. In reality, all scores are between 0.25 and 0.6 (between 25 and 60 on the 0 to 100 scale).
Statistics
The table below is about the world Gini coefficient (not by single countries).
| Year | World Gini index[1][2][3] |
|---|---|
| 1820 | 0.43 |
| 1850 | 0.53 |
| 1870 | 0.56 |
| 1913 | 0.61 |
| 1929 | 0.62 |
| 1950 | 0.64 |
| 1960 | 0.64 |
| 1980 | 0.66 |
| 2002 | 0.71 |
| 2005 | 0.68 |
The table below shows the income Gini coefficient of the United States from 1947 to 2009.
| Year | pre-tax Gini |
|---|---|
| 1947 | 0.413 |
| 1967 | 0.397 |
| 1968 | 0.386 |
| 1970 | 0.394 |
| 1980 | 0.403 |
| 1990 | 0.428 |
| 2000 | 0.462 |
| 2005 | 0.469 |
| 2006 | 0.470 |
| 2007 | 0.463 |
| 2008 | 0.467 |
| 2009 | 0.468 |
Gini Coefficient Media
Map of income inequality Gini coefficients by country (%). Based on World Bank data ranging from 1992 to 2020.*Template:Legend-col*
A different map showing wealth Gini coefficients within countries for 2019
Share of income of the top 1% for selected developed countries
The Gini coefficient is equal to the area marked A divided by the total area of A and B, i.e. \text{Gini}=\tfrac{A}{A+B} . The axes run from 0 to 1, so A and B form a triangle of area \tfrac{1}{2} and \text{Gini} = 2A = 1-2B .
Gini coefficient for distribution with only two income or wealth levels
Gini indices of selected countries are from publicly available data from the World Bank, Nationmaster, and the US Census Bureau. *The Gini index is the Gini coefficient expressed as a percentage, and is equal to the Gini coefficient multiplied by 100. The Gini coefficient is a measure of statistical dispersion most prominently used as
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References
- ↑ Isabel Ortiz and Matthew Cummins (2011). "Global inequality: beyond the bottom billion" (PDF). UNICEF. Archived from the original (PDF) on 2012-08-12. Retrieved 2012-09-14.
- ↑ Evan Hillebrand (2009). "Poverty, growth, and inequality over the next 50 years" (PDF). FAO, United Nations - Economic and Social Development Department. Archived from the original (PDF) on 2017-10-20. Retrieved 2012-09-14.
- ↑ Albert Berry and John Serieux (2006). "Riding the elephants: the evolution of world economic growth and income distribution at the end of the twentieth century (1980-2000)" (PDF). United Nations (DESA Working Paper #27).