Questions about the nature of money have gained a new urgency in the aftermath of the global financial crisis. Even as many people have less of it, there are more forms and systems of money, from local currencies and social lending to mobile money and Bitcoin. Yet our understanding of what money is—and what it might be—hasn't kept pace. In The Social Life of Money, Nigel Dodd, one of today’s leading sociologists of money, reformulates the theory of the subject for a postcrisis world in which new kinds of money are proliferating. What counts as legitimate action by central banks that issue currency and set policy? What underpins the right of nongovernmental actors to create new currencies? And how might new forms of money surpass or subvert ...