Cross-national research on the causes and consequences of income inequality has been hindered by the limitations of the existing inequality datasets: greater coverage across countries and over time has been available from these sources only at the cost of significantly reduced comparability across observations. The goal of the Standardized World Income Inequality Database (SWIID) is to meet the needs of those engaged in broadly cross-national research by maximizing the comparability of income inequality data while maintaining the widest possible coverage across countries and over time. It incorporates data from the United Nations University’s World Income Inequality Database, the OECD Income Distribution Database, the Socio-Economic Database for Latin America and the Caribbean generated by CEDLAS and the World Bank, Eurostat, the World Bank’s PovcalNet, the UN Economic Commission for Latin America and the Caribbean, the World Top Incomes Database, the University of Texas Inequality Project, national statistical offices around the world, and academic studies while minimizing reliance on problematic assumptions by using as much information as possible from proximate years within the same country. The data collected by the Luxembourg Income Study is employed as the standard. The SWIID currently incorporates comparable Gini indices of net and market income inequality for 174 countries for as many years as possible from 1960 to the present; it also includes information on absolute and relative redistribution. A full description of the SWIID, the procedure used to generate it, and an assessment of the SWIID’s performance in comparison to the available alternatives is presented here:

Solt, Frederick. Forthcoming. “The Standardized World Income Inequality Database.” Social Science Quarterly.

There are two ways of using the SWIID. To directly compare up to four countries in estimated levels and trends of (a) inequality in net (post-tax, post-transfer) income, (b) inequality in market (pre-tax, pre-transfer) income, (c) absolute redistribution (market-income inequality minus net-income inequality), or (d) relative redistribution (market-income inequality minus net-income inequality, divided by market-income inequality), or to compare several of these measures in a single country, use the SWIID web app below. To use the SWIID in statistical analyses, datasets formatted for Stata or R can be downloaded here: Download SWIID Version 5.0, released October 2014.



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Please cite the SWIID as follows:

Solt, Frederick. 2014. “The Standardized World Income Inequality Database.” Working paper. SWIID Version 5.0, October 2014.
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