Berkeley - John C. Harsanyi, winner of the 1994 Nobel Memorial Prize in Economic Sciences and a longtime professor at the University of California, Berkeley's Haas School of Business and its Department of Economics, died of a heart attack at his home in Berkeley on Wednesday, Aug. 9.

He was 80 and had been suffering from Alzheimer's Disease.

Harsanyi was awarded the Nobel Prize for his work in game theory, a mathematical theory of human behavior in competitive situations that has become a dominant tool for analyzing real-life conflicts in business, management and international relations.

He shared the award from the Royal Swedish Academy of Sciences with fellow game theorists Reinhard Selten of Rheinische Friedrich-Wilhelms-Universitaet in Bonn, Germany, and John Nash of Princeton University.

When Harsanyi, an immigrant from communist Hungary, won the Nobel Prize, he expressed hope that game theory would help public and private institutions make better decisions. In the long run, he said, he hoped this would lead to a higher standard of living and to more peaceful and more cooperative political systems.

"Professor Harsanyi's life-long work probed the idea of rationality in human affairs, and he was a scholar who cared deeply about the human condition. We will miss him at Berkeley, where his years of devoted teaching and his ground-breaking research inspired us all," said Chancellor Robert M. Berdahl.

Harsanyi began teaching at UC Berkeley in 1964 as a visiting professor in the business school. He became a full professor in 1965 and remained on the faculty of the Haas School of Business until his retirement in 1990. Harsanyi accepted a joint appointment on the economics faculty in 1966.

"John Harsanyi dedicated his life to employ the science of economics and game theory for the betterment of the human race," said Haas School Dean Laura Tyson. "He was a brilliant thinker, a gracious man, and a gentle soul, ever concerned with the well-being of others. We will all miss him dearly."

"The passing of John Harsanyi is a great loss to the economics profession and to his many friends and colleagues on this campus," said John Quigley, UC Berkeley professor of economics and former chair of the department. "Harsanyi's work was instrumental in making economic theory 'fit' the imperfect world in which we live. His development of game theory showed how differences in the information available to economic actors affected market outcomes and economic welfare. His seminal works form the basis for all modern analyses of industrial organization, and they have real practical implications in business and government policy.

"John was a gentle and shy man, but a bold and powerful intellectual presence. We will miss his grace and charm."

Game theory uses mathematics to try to predict the outcome of games, such as chess or poker, and is increasingly being applied to political and economic conflict situations, including labor negotiations, price wars, international political conflicts, and even federal auctions, such as bandwidth auctions.

Harsanyi's principal contributions to the field addressed the prediction of outcomes in games or situations in which the players lack complete information about each other or the rules of the game.

In 1964, Harsanyi was asked to be one of 10 game theorists to advise the United States Arms Control and Disarmament Agency on its negotiations with the Soviet Union. The team found that it could not advise the U.S. negotiators effectively because neither side knew much about the other - it was a game of incomplete information.

Harsanyi subsequently developed a systematic procedure to convert any incomplete-information game into an equivalent complete-information game containing random moves, thereby significantly expanding the applicability of game theory to political and economic conflicts. In the late 1960s, Harsanyi described this theory in a three-part article, "Games with Incomplete Information Played by Bayesian Players," which is now the basis for all work on games with incomplete information.

Harsanyi was born on May 29, 1920, in Budapest, Hungary, as the son of a Catholic pharmacist of Jewish descent and was educated at the University of Budapest. His main interests were in mathematics and philosophy, but because of the uncertain political situation and the impending Nazi danger, Harsanyi opted to obtain a degree in pharmacology so he could work in his father's pharmacy.

In 1944, the Germans occupied Hungary, and Harsanyi, being of Jewish descent, was drafted into a forced-labor unit near Budapest. Shortly thereafter, the Nazis started deporting these laborers to mines and concentration camps. Harsanyi narrowly escaped deportation and found refuge with three friends at a Jesuit monastery in Budapest.

After the war, Harsanyi earned a PhD in philosophy at the University in Budapest where he later taught as an assistant professor of sociology and also met his future wife, Anne. In 1948, a Stalinist regime seized power in Hungary and became increasingly intolerant of Harsanyi's liberal views. Eventually, he had to resign from the university and return to work in his father's pharmacy.

Pressure on Harsanyi persisted and, in 1950, the family decided it was too dangerous for him to remain in Hungary. Harsanyi and his soon-to-be wife, Anne, escaped across the border to Austria, and emigrated to Australia, as the waiting list of the Hungarian immigration-quota to the United States was full. The couple were married on January 2, 1951, three days after arriving in Sydney.

In Sydney, Harsanyi worked in factories during the day while earning an MA in economics at the University of Sydney at night. In 1954, he was appointed lecturer in economics at the University of Queensland in Brisbane.

Harsanyi soon realized he was too isolated in Australia to be effective in his field. In 1956, he enrolled in the PhD program in economics at Stanford University, writing his dissertation on game theory under the guidance of the future Nobel Laureate Kenneth Arrow.

Before arriving at UC Berkeley in 1964, he taught economics at the Australian National University in Canberra from 1958 to 1961 and at Wayne State University in Detroit from 1961 to 1963. At Berkeley, he continued his path-breaking work in game theory and also made important contributions to the fields of ethics, social choice and welfare economics. Harsanyi was awarded seven honorary doctorates by universities around the world. Harsanyi is survived by his wife, Anne, of Berkeley, and son, Tom, of Somerville, Mass.

When Harsanyi was interviewed in Budapest after being awarded the Nobel Prize, he said his family and his work were the most important things in his life. He took frequent trips all over the world with his family.

A memorial service for the campus community will be held at 4 p.m. on Thursday, Aug. 31, in the Great Hall of UC Berkeley's Faculty Club.

Donations in John Harsanyi's memory may be sent to the Alzheimer's Association of the Greater Bay Area, 2065 West El Camino Real, Mountain View, CA 94042.