Mission: To provide open and convenient access to data illustrating the historical evolution of the world distribution of income and wealth, both within countries and between countries.
Background: In the last decade and a half, interest in income and wealth inequality has grown considerably. Pioneers of income inequality studies include Simon Kuznets (1953) and A. B. Atkinson and Alan Harrison (1978). Picking up the mantle, University of California at Berkeley economists Gabriel Zucman and Thomas Piketty have advanced research on aggregate wealth-to-income ratios and created, in partnership with Facundo Alvaredo, Lucas Chancel and Emmanuel Saez, The World Inequality Report, which in turn led to calls for their data series to be made publicly available. Initially launched as The World Top Incomes Database (WTID) in January 2011, WTID subsequently was expanded to include series on income inequality for more than thirty countries, spanning over most of the twentieth and early twenty-first centuries. In December 2015, WTID was subsumed into WID, a change reflecting the expansion, in scope and ambition, of the project, as well as a new focus on both wealth and income. In an effort to reach a wider audience of researchers and the general public, an initial version of a more user-friendly site to host the World Inequality Database, WID.world, was launched in January 2017. Improvements to the database included an expansion of the time coverage and geographical coverage of the data; continuous updating of the database with new observations as official bodies release the information each year; and the inclusion of inequality series at the sub-national level whenever possible. Down the road, the site plans to produce Distributional National Accounts (DINA), annual estimates of the distribution of income and wealth using concepts of income and wealth that are consistent with macroeconomic national accounts.
Outstanding Web Features: The site provides research tools for scholars, journalists, or anyone interested in producing their own inequality dataset. Visitors to the site can explore an interactive world view that shows inequality between countries according to key indicators (average income, average wealth, income inequality, and wealth inequality). Visitors also can explore inequality in individual countries via user-friendly country graphs or download open-access datasets. The site also provides an income distribution simulator that allows visitors to see their income position relative to the income of others. For additional information, visitors can download the World Inequality Report, review the methodology behind the site, browse the site's library and individual publications, search a compendium of research tools, check out the latest news, and sign up for updates on upcoming events hosted by the World Inequality Lab.