Martin Ravaillon has written an interesting review of two books I mentioned before in this blog, by François Bourguignon and Branko Milanovic respectively. His main criticism of the two books is that they have been publicized as establishing a causal link between globalization and global inequality, Ravaillon argues that it is not clear that global inequality has increased in the recent decades, because of data issues that prevent us from establishing firm statements and because different measures of inequality provide different conclusions. Global inequality is the combination of inequality between countries and inequality within countries. Althought inequality between countries may have decreased because of rapid growth of some large previously poor countries (like India and China), within country inequality has increased in some cases, although not in all as Ravaillon explains. In the famous graph of Milanovic's elephant, which is based on relative changes in income for the world's population, clearly the emeging middle classes from India and China have done better than the working and middle clases of the developed world (which means that between the 30% poorest and the 80% those closer to the 30% have done better, reducing global inequality), but the richest of the world have done much better than all those preceding them (increasing global inequality). If instead of using relative income we reproduced Milanovic's famous graph using absolute income, the elephant actually would become a giraffe, because the relative increase in income of the middle classes of the poor world is a very small amount of money in absolute terms (so the head of the elephant disappears), whereas the relative increase of the richest is a lot of money. Ravaillon argues that this may be at the root for why so many citizens have the perception that global inequality has increased when (perhaps) it has not. The advantages and disadvantages of relative versus absolute measures of inequality can be studied for example here. He also argues that the changes in global inequality cannot clearly be attributed to globalization, and therefore we should not easily blame this for any political consequences of the changes in inequality. Certainly lots of other things were happening at the same time together with globalization. At the end of the article he somehow unclearly argues that there are not many arguments to care about inequality at the global level more than we care about global poverty. But I find this unconvincing; just as national inequality may hurt growth and democracy nationally, global inequality may hurt global growth and welfare and distabilize the expansion of democracy globally.