Comparable Indicators of Inequality Across Countries
income inequality statistics currently available, for about 160 countries. It documents the sources of the data and
the income definition, area and population covered, and reference unit for each observation, allowing research-
ers to choose observations so as to maximize comparability by choosing only those observations with identical
values on these criteria. This may involve discarding most of the observations, however, so both the Standardized
Income Distribution Database (SIDD) created by Babones and Alvarez-Rivadulla (2007) and the Standardized
World Income Inequality Database SWIID (Solt, 2008) maintain wider coverage across countries and over time by
in effect estimating values for the desired definition for each year using observations relating to other definitions/
years. Babones and Alvarez-Rivadulla calculated the average differences between various income definitions and
reference units and used these as constant adjustments to produce a single series representing household per capita
gross income inequality. The SWIID employs a more complex estimation procedure and benchmarks to LIS data
where available, and provides comparable Gini indices of gross and net income inequality for 153 countries for
as many years as possible from 1960 to the present along with estimates of uncertainty in these statistics. While
each of these sources provide data in readily downloadable form, the SWIID is currently the most relevant for
the purposes of the GINI project (available from http://dvn.iq.harvard.edu/dvn/dv/fsolt/faces/study/StudyPage.
xhtml?studyId=36908). Atkinson and Morelli (2010, 2011) have very recently constructed an inequality database
for 25 countries covering a very long period, in some cases back as far as 1911-2010, and are using this to look at
the relationship between inequality and financial crises.
There have also been initiatives providing cross-nationally harmonized panel data such as the Cross National
Equivalent File which covers the USA, Canada, Germany, Britain and Australia (Burkhauser et al., 2001). Finally,
for the very top of the income distribution the top income shares data covering a range of OECD countries com-
piled by Atkinson and Piketty and used by, for example, Leigh (2007) and Roine, Vlachos and Waldenstrom (2007)
can be employed. For an overview see Atkinson, Piketty and Saez (2010); the complete database is available online
at the Paris School of Economics at http://g-mond.parisschoolofeconomics.eu/topincomes/.
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