Stiglitz is perhaps best known for his unrelenting assault on an idea that has dominated the global landscape since Ronald Reagan: that markets work well on their own and governments should stay out of the way. Since the days of Adam Smith, classical economic theory has held that free markets are always efficient, with rare exceptions. Stiglitz is the leader of a school of economics that, for the past 30 years, has developed complex mathematical models to disprove that idea. The subprime-mortgage disaster was almost tailor-made evidence that financial markets often fail without rigorous government supervision, Stiglitz and his allies say. The work that won Stiglitz the Nobel in 2001 showed how “imperfect” information that is unequally shared by participants in a transaction can make markets go haywire, giving unfair advantage to one party. The subprime scandal was all about people who knew a lot—like mortgage lenders and Wall Street derivatives traders—exploiting people who had less information, like global investors who bought up subprime- mortgage-backed securities. As Stiglitz puts it: “Globalization opened up opportunities to find new people to exploit their ignorance. And we found them.”