STOCKHOLM — Americans Elinor Ostrom and Oliver Williamson won the Nobel economics prize today for their analyses of economic governance — the rules by which people exercise authority in companies and economic systems.

Ostrom was the first woman to win Nobel Memorial Prize in Economic Sciences since it was founded in 1968, and the fifth woman to win a Nobel award this year, a record for the prestigious honors.

It was also an exceptionally strong year for the United States, with 11 American citizens — some of them with dual nationality — among the 13 Nobel winners.

The academy said over the last three decades, the work done by Ostrom and Williamson had "advanced economic governance research from the fringe to the forefront of scientific attention." It said their research showed that economic analysis can shed light on most forms of social organization.

Issues of governance have been at the heart of the ongoing world economic crisis. The failure by boards of directors, for instance, to police excessive compensation, or prevent bonuses that reward excessive risk taking, can be considered a corporate governance issue.

Ostrom is at Indiana University. Williamson is at the Walter A. Haas School of Business at the University of California, Berkeley.