This paper provides an overview of historic worldwide trends in relative and absolute income inequality. Depending on the concept used, inequality trends differ considerably. Inequality between countries increased strongly during 1820-2000 and started decreasing at the beginning of the twenty-first century, whether measured in relative or absolute terms. Within-country inequality, on the contrary, grew especially strongly during the last decades: Its growth rate accelerated after 1950 in absolute terms and after 1975 in relative terms. Absolute global inequality also increased substantially in the post-1950 period, whereas relative global inequality decreased slightly during this period.
