Elinor Ostrom, the only woman to win the Nobel Memorial Prize in Economic Science — an achievement all the more remarkable because she was not actually an economist — died on Tuesday in Bloomington, Ind. She was 78.

The cause was cancer, according to Indiana University, where she taught for many years.

Professor Ostrom’s work rebutted fundamental economic beliefs. But to say she was a dark horse for the 2009 economics Nobel is an understatement. Not because she was a woman — although women in the field are still rare — but because she was trained in political science.

Professor Ostrom’s prizewinning work examined how people collaborate and organize themselves to manage common resources like forests or fisheries, even when governments are not involved. The research overturned the conventional wisdom about the need for government regulation of public resources.

At least it did for the economists who knew who she was and had read her work.

“The announcement of her prize caused amazement to several economists, including some prominent colleagues, who had never even heard of her,” Avinash Dixit, a Princeton economics professor, said when introducing Professor Ostrom’s work at a luncheon in 2011. Usually, he noted, Nobel laureates need no introduction.