In recent years, debates about inequality have reached a renewed intensity in international policy debates. This is partly the result of much better data on the extent of inequality, where the work by Piketty on the top 1% has revealed much larger (and rising) inequality than previously known from household surveys. Similarly, work on global inequality in incomes and wealth have generated eye-catching results about the massive levels of global inequality in incomes, and even more so in wealth. Lastly, the renewed interest in inequality is also the result of rising inequality in many developing countries since the 1980s which has contributed in many places to social and political instability. In consequence, it is not surprising that the Sustainable Development Goals have included reducing inequality as a new goal.