STOCKHOLM - The Nobel Prize in economics was awarded to three Americans Monday for their research into why some countries succeed and others fail. Two of the three economists are professors at the Massachusetts Institute of Technology in Cambridge.

Daron Acemoglu and Simon Johnson, of MIT, and James A. Robinson, of the University of Chicago, won the prize Monday for research into differences in prosperity between nations.

Their research centered around tracing the roots of the question: "Why are some countries poorer and others more prosperous? And why do those inequalities persist?"