By CATHERINE RAMPELL

Published: June 12, 2012

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 toIndiana 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.

In fact, when the Nobel recipients were announced, some economists mistakenly thought the prize had gone to Bengt Holmstrom,an economist with a similar-sounding (and, to economists, much more recognizable) name. One prominent scholar acknowledged visiting Wikipediato figure out who exactly she was.

Surprise at Professor Ostrom’s honor, which she sharedwith Oliver E. Williamson, in some cases gave way to disdain and name-calling on economics blogs.

“Some things said about her in blogs and other media were so ignorant and in such bad taste that I felt ashamed on behalf of the economics profession,” Mr. Dixit said.

Professor Ostrom was not the first laureate to hail from outside the field. Previous recipients include Daniel Kahneman(psychologist), John Nash (a mathematician who was the subject of the book and movie “A Beautiful Mind”) and Leonid Hurwicz(trained in law).

As with these other winners, the outsider perspective Professor Ostrom brought to the field contributed to what made her work so groundbreaking. But the unconventional nature of her studies also made it difficult for her to find a foothold in academia earlier in her career.

“A lot of important questions are on the narrow borders between disciplines, but it is difficult to find a home for that kind of work,” said Marco Janssen, a mathematician at Arizona State University who collaborated with Professor Ostrom. “She had experienced many of these challenges over the years. Eventually she and her husband just created their own center for it.”

In 1973, Professor Ostrom and her husband, Vincent, who survives her, founded the Workshop in Political Theory and Policy Analysis at Indiana University. It would become the first of several interdisciplinary institutions she helped shape, and a locus for her collaboration with scholars across academia, including ecologists, computer scientists and psychologists.

Just as her academic habits emphasized collaboration and cooperation, so did the content of her study.

Traditionally, economics taught that common ownership of resources results in excessive exploitation, as when fishermen overfish a common pond. This is the so-called tragedy of the commons, and it suggests that common resources must be managed either through privatization or government regulation, in the form of taxes, say, or limits on use.

Professor Ostrom studied cases around the world in which communities successfully regulated resource use through cooperation. Her work has important applications for climate changepolicy today.

Professor Ostrom’s research and Mr. Williamson’s related work on corporate oversight are part of a field known as institutional economics. Some economists still debatewhether the field deserves a rightful place within the economics discipline.

Elinor Awan was born on Aug. 7, 1933, in Los Angeles, an only child. She often spoke about how growing up in the Depression had influenced her interest in cooperative institutions. She recalled helping her family grow food in a large garden and knitting scarves for soldiers. She received her bachelor’s, master’s and doctoral degrees — all in political science — at the University of California, Los Angeles.

As a researcher she was notable for conducting fieldwork, an unusual method that is admired by some economists but scorned by others. In 1964, when she was working on her dissertation, fieldwork was considered the province of anthropologists, not academics trying to answer economic questions.

“She would go and actually talk to Indonesian fisherman, or Maine lobstermen, and ask, ‘How did you come to establish this limit on the fish catch? How did you deal with the fact that people might try to get around it?’ ” said Nancy Folbre, an economics professor at the University of Massachusetts, Amherst, and a contributor to The New York Times’s Economix blog.

“In economics, every successive cohort of economists is trained to put greater emphasis on the arsenal of mathematical and econometric expertise,” Professor Folbre said. “That was just not what her work was about.”