Database
World Income Inequality Database - WIID


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. ​

This page hosts the latest version of WIID and, for the first time, a WIID Companion — separate datasets that report standardized WIID data to create comparable country level inequality series, inequality indices, and country and global income distributions for the longest periods possible.

Latest version of WIID

WIID provides the most comprehensive set of income inequality statistics available

With this current WIID version, the observations now reach the year 2019 and covers 200 countries (including historical entities) with over 20,000 data points in total. There are now more than 3,700 unique country-year observations in the database. Read more about the observation composition here

Excel Stata User guide Revision note
File WIID_31MAY2021 Package icon WIID_31MAY2021 PDF icon WIID User Guide PDF icon WIID Version Note

Please cite this database version as UNU-WIDER, World Income Inequality Database (WIID). Version 31 May 2021. https://doi.org/10.35188/UNU-WIDER/WIID-310521

The WIID Companion

The WIID Companion reports annual country and global per capita income distributions at the percentile level.

For the first time, 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. 

Excel Stata User guide Revision note
File wiidcountry.xlsx Package icon wiidcountry.zip PDF icon User Guide PDF icon Version Note
File wiidglobal.xlsx Package icon wiidglobal.zip    

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 31 May 2021. https://doi.org/10.35188/UNU-WIDER/WIIDcomp-310521

Resources

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

Package icon Stata package.zip

Contact the WIID team

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.