If the world's income distribution has become more equal in the past few decades, this would be powerful evidence that globalisation works to the benefit of all. It would give developing countries good reason to integrate their economies closely into the world economy, as the IMF and the World Bank and their mostly rich-country shareholders urge them to do. It would answer some of the fears of the anti-globalisation protesters. And it would help to settle a crucial and long-standing disagreement in economic theory, between the orthodox view that economic growth naturally delivers 'convergence' of rich and poor countries, and alternative theories which, for one reason or another, say the opposite. Neither the World Bank nor the IMF has devoted significant resources to studying it.
Many analysts apparently take it for granted that global inequality is falling.
Others think it sufficient to focus on poverty, and ignore inequality as such. Both these views need to be challenged. New evidence suggests that global inequality is worsening rapidly. There are good reasons to worry about that trend, quite apart from what it implies about the extent of world poverty. This article is concerned with distribution among the planet's 6.2 billion people, regardless of country or region.