Elinor Ostrom, Arthur F. Bentley professor of political science and co-director of the workshop in political theory and policy analysis at Indiana University Bloomington “for her analysis of economic governance, especially the commons”.
And:
Oliver Williamson, professor emeritus of business, economics, and law at the University of California Berkeley “for his analysis of economic governance, especially the boundaries of the firm”.
The Nobel Committee’s announcement can be found here.