New release of the World Income Inequality Database – new WIID version includes updates to the WIID Companion datasets

The UNU-WIDER World Income Inequality Database―widely known by its acronym WIID―provides the most comprehensive set of income inequality statistics available. It presents detailed information on income inequality for most countries and historical entities (201). The latest version of the WIID can be downloaded here.

The newest version builds on the June 2022 release. It updates the WIID through 2022 to its current level with over 24,000 data points and nearly 4,000 unique country-year observations.

It is also released alongside an updated WIID Companion. The WIID Companion offers a more user-friendly, curated set of inequality statistics. In the WIID Companion, most of the necessary data selection and adjustment needed to analyse, describe, or compare levels of inequality between countries or over time has already been taken care of by UNU-WIDER’s inequality and data experts. 

The WIID Companion reports annual country and global per capita income distributions at the percentile level. It also includes a set of measures that summarize the distribution, including relative and absolute inequality indices and various income share ratios. It consists of two datasets. The first is a country-level inequality dataset that contains a single series per country tracking the net per capita income distribution. The second reports on global inequality.

Read more about the WIID Companion here.  

About the WIID

For more than 20 years, the WIID has been used for research on global inequality. It has been used to analyse inequality trends across countries and to study the relationships between inequality and, for example, economic growth and development, public sector expansion, political conflict, religiosity, etc.

Initially compiled in 1997–99 for the UNU-WIDER/UNDP project Rising income inequality and poverty reduction: Are they compatible? and published in September of 2000, the WIID is a major public good which contributes to understanding inequality and monitoring progress towards the achievement of reduced inequalities in line with Sustainable Development Goal 10.

Database composition
Observations by variable type  Number of observations
Total observations24,367
Gini coefficients24,279
MLD indices (GE0)11,723
Theil indices (GE1)13,395
Palma indices19,007
Bottom 40 per cent income shares18,860
Income distribution by quintile shares18,859
Income distribution by decile shares18,058
Time spanNumber of observations
Total observations24,367
Before 1960311