These assumptions ignore key lessons of the last four decades and of economic history more generally. Development is something largely determined by poor countries themselves, and outsiders can play only a limited role. Developing countries themselves emphasize this point, but in the rich world it is often forgotten. So too is the fact that financial aid and the further opening of wealthy countries’ markets are tools with only a limited ability to trigger growth, especially in the poorest countries. The tremendous amount of energy and political capital expended on these efforts in official circles threatens to crowd out attention to other ways in which rich countries could do less harm and more good.