“Economic development is not a zero-sum game; the world does not need poor countries in order to have rich countries, nor must some people be poor in order for others to be rich. Families who live in public housing on the South Side of Chicago are not poor because Bill Gates lives in a big house. They are poor despite the fact that Bill Gates lives in a big house. For a complex array of reasons, America’s poor have not shared in the productivity gains spawned by Microsoft Windows. Bill Gates did not take their pie away; he did not stand in the way of their success or benefit from their misfortunes.”