Chapter 5 Empirical evidence on income inequality in industrialized countries This chapter reviews the evidence on cross national comparisons of annual disposable income inequality in over 20 wealthy nations. We begin by reviewing a number of conceptual and measurement issues which must be addressed by any cross national comparison of survey based household income data. With these caveats in mind we present data on both the level of inequality during the early to mid 1990s and in inequality trends since 1970. While most comparisons are made in terms of relative incomes within nations we also make some real income comparisons at a point in time using purchasing power parities. The data indicate that a wide range of inequality exists across these rich nations during this decade with the most unequal nation experiencing a level of inequality which is more than twice the level found in the most equal nation. Country specific trends in income inequality are more similar although not universally so. The large majority of nations have experienced rising income inequality over the last decade or longer. This increase is not offset by changes in income mobility over this period and follows a period of declining income inequality in most of these same nations.