Changes in inequality within countries after 1990

In this paper, we use the World Income Inequality Database to assess the main trends in inequality within countries since around 1990. We cope with the heterogeneity in the original information (regarding the measure of resources, equivalence scale, etc.) by focusing on the trends rather than on the levels, and by comparing like to like within countries. With only a few exceptions, we compare the same inequality concept obtained from the same source in two different years in each country, even if the concept and source will differ across countries.