Since the writings of Adam Smith, economists have understood the important role that private property rights play in a well-functioning economic system. Without well-defined, enforced, and transferable property rights, the tragedy of the commons is said to result as in the classic case of overfishing and overgrazing. This book challenges this narrow view of property rights by examining the role of informal constraints imposed by customs and culture. Recognizing that a great deal of human interaction takes place in the absence of individually specified rights, the authors challenge the notion that tragedy is inevitable within the commons.