Since the financial crisis, economists such as Joseph Stiglitz of Columbia, Raghuram Rajan of the University of Chicago, and even staffers at the International Monetary Fund have begun to argue that income inequality causes economic damage. Not only does extreme inequality such as now seen in the U.S. threaten social comity, they argue, but also, by tending to fuel crises and other busts, it undermines a nation’s capacity to sustain growth.