Gini Coefficient
The Gini coefficient — a single number between 0 (perfect equality) and 1 (one person has everything) — is the most widely used inequality measure. Country values range from ~0.25 (Slovakia, Belgium, Slovenia) to ~0.65 (South Africa). Post-tax-and-transfer Ginis are 8–18 points below pre-tax Ginis in most OECD economies; redistribution does substantial work even when it's politically invisible.
Key insights
The measure has known weaknesses
The Gini is sensitive to changes in the middle of the distribution and less responsive to changes at the tails. Two distributions can have identical Ginis but very different top-shares or bottom-shares. Complementary measures: top-10% share, top-1% share, Palma ratio (top-10%/bottom-40%), Atkinson index. Most policy debates need more than one statistic; the Gini is a starting point not a conclusion.
South Africa, Brazil and Colombia top the Gini league
South Africa's Gini of ~0.63 reflects post-apartheid wealth and income concentrations that have proven sticky. Brazil's Gini has fallen from ~0.60 (2000) to ~0.53 (2024) through Bolsa Família, minimum-wage policy and education expansion — one of the largest sustained inequality reductions on record. Colombia, Costa Rica and several Andean countries also sit in the 0.45-0.55 range.
Pre- vs post-redistribution gaps are large
France's pre-tax Gini is ~0.51; post-tax-and-transfer ~0.30. Sweden's pre-tax is similar but post-tax ~0.27. Most of European 'equality' comes from redistribution, not from compressed market wages. The US pre-tax Gini is ~0.51 — similar to Sweden — but post-tax only falls to ~0.39 because of more limited transfers. The market doesn't differ across rich countries as much as the welfare state does.
Income Gini coefficient — selected countries (post-tax-and-transfer)
Disposable household income Gini, latest available
Key Finding: South Africa, Brazil, Mexico, US lead on inequality. Northern European countries and Eastern European post-communist economies sit lowest.
Redistribution effect — pre vs post tax-and-transfer Gini (OECD)
Difference between market-income Gini and disposable-income Gini
Key Finding: Continental European countries and the Nordics achieve the largest redistribution. The US redistributes least among major economies.
Methodology & caveats
Gini computation
Gini = area between the Lorenz curve and the perfect-equality 45° line, divided by area below the 45° line. The Lorenz curve plots cumulative share of population (sorted by income) vs cumulative share of income. The single-number summary loses information but is comparable across countries and time.
Income definition matters
Gini values depend on: (1) market income vs disposable income, (2) household vs individual unit, (3) equivalence scale (how household income is divided across members), (4) inclusion of in-kind benefits (healthcare, education, housing subsidies). Cross-country comparisons should specify the conventions used. OECD data uses standardized definitions; raw country surveys often don't.
Wealth Ginis are higher
Wealth Ginis are typically 0.7-0.9 — much higher than income Ginis (typically 0.25-0.55). Wealth accumulates over a lifetime; income flows in real time. A 25-year-old with zero wealth and a $50k income isn't poor; a 75-year-old with $50k income and $2M house isn't middle-class. Wealth-inequality statistics need careful interpretation around life-cycle effects.