Poverty & Inequality · Glossary
Gini index
SI.POV.GINI
Definition
Gini index measures the extent to which the distribution of income (or, in some cases, consumption expenditure) among individuals or households within an economy deviates from a perfectly equal distribution. A Lorenz curve plots the cumulative percentages of total income received against the cumulative number of recipients, starting with the poorest individual or household. The Gini index measures the area between the Lorenz curve and a hypothetical line of absolute equality, expressed as a percentage of the maximum area under the line. Thus a Gini index of 0 represents perfect equality, while an index of 100 implies perfect inequality.
Methodology for Poverty & Inequality indicators
Poverty and inequality measures use household income or consumption surveys (LSMS, EU-SILC, national equivalents), which are typically conducted every 3–5 years. Between survey years, figures are interpolated or projected. The international poverty line is set at $2.15/day in 2017 PPP — a real (purchasing-power) threshold, not a nominal one. Gini coefficients have wide confidence intervals; small year-over-year changes are usually not meaningful.
How to interpret
- Always check the unit and reporting year before comparing values across countries.
- NULL or "Not available" means the World Bank did not publish a value — we never estimate.
- Year-over-year changes can be driven by methodology updates, not just real economic shifts.