The capitalist economy is surrounded by a boundary, outside which stands the non-capitalist, non-market world. The task of development economics is to help extend the rules of the market into these other spaces. The popularity of such proposals can be gauged by the success of the work of Hernando de Soto, a Peruvian entrepreneur and economist, whose two books, The Other Path (1989) and The Mystery of Capital (2000), have become the most widely cited studies of non-western economic development in a generation. This chapter investigates this conception of the market and its limits.