The World Income Inequality Database (WIID) presents information on income inequality for developed, developing, and transition countries. It provides the most comprehensive set of income inequality statistics available and can be downloaded for free.
The latest version of the WIID, released 31 May 2021, covers 200 countries (including historical entities) through 2019, with over 20,000 data points in total. There are now more than 3,700 unique country-year observations in the database.
As a part of the UNU-WIDER 2019-23 work programme on transforming economies, states, and societies, we have produced a more user-friendly companion database to the classic WIID that will greatly simplify using the WIID for cross-country comparative analysis.
After 20 years of contributions to income inequality research, the WIID now includes a new expansion — the WIID Companion — to strengthen knowledge on income inequality. The companion provides an integrated series of net per capita income inequality data for each country, curated to best reflect the trends over the time and enable comparability across countries and over time, as well as new indicators of inequality — such as the Theil, the Atkinson, and the Palma index. It also contains the income shares for the entire national distribution and offers a complete global income distribution over time, estimated to the percentile level.
The World Income Inequality Database project is also working to publish and disseminate new research on income inequality, create opportunities to engage, and host events.
Watch this space
All papers, data and opinion pieces relating to this project, as well as opportunities to engage will be available on this webpage.
This project centrally addresses SDG 10 (reduce inequality within and among countries).