Database
World Income Inequality Database - WIID

This current version of the WIID now reaches the year 2022 and covers 201 countries (including historical entities) with over 24,000 data points in total. There are now more than 4,000 unique country-year observations in the database. Read more about the observation composition here. 

Please cite this database version as UNU-WIDER, World Income Inequality Database (WIID). Version 28 November 2023. https://doi.org/10.35188/UNU-WIDER/WIID-281123

Along with the main dataset, UNU-WIDER provides a WIID Companion, which consists of two companion datasets. One of these reports inequality data by country and the other reports inequality data globally, including the global distribution.

These datasets offer a more user-friendly, curated set of inequality statistics with 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 our 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. Thus, the WIID Companion represents trends in the income distribution within countries, between countries, and globally to improve the study of income inequalities and contribute to better monitoring of inequality trends. 

Resources are available with detailed information on how to use the WIID Companion datasets. There are also three WIDER Technical Notes describing construction of the WIID Companion datasets. For more advanced users, we also provide a Stata file package which can be used to replicate the steps taken in the construction of the WIID Companion.

Please cite this database as UNU-WIDER, World Income Inequality Database (WIID) Companion dataset (wiidcountry and/or wiidglobal). Version 28 November 2023. https://doi.org/10.35188/UNU-WIDER/WIIDcomp-281123

Resources

User Guide
Technical Note: Data Selection
Technical Note: Standardized Series
Technical Note: Global Income Distribution

Please contact the WIID team for any questions about the database. We also encourage comments on this version and contributions of updated data points. The database will be regularly updated. Notifications and details about updates will continue to be given on this website. Some minor corrections may be done without a change in the database version.