I N T H E L A S T T H I R T Y Y E A R S , the scope of economics has expanded dramatically beyond its traditional domain of explicit market transactions.1 Today there is an economic theory of property rights, of corporate and other organizations, of government and politics, of education, of the family, of crime and punishment, of anthropology, of history, of information, of racial and sexual discrimination, of privacy, even of the behavior of animals-and, overlapping all these but the last, of law.2