Analysis / World honors contribution to game theory - and a noble player

_{By Ariel Rubinstein}

Israel Robert Aumann is a man of Jerusalem. He loves this city where he settled when he immigrated to Israel as a young man. He did most of his highly acclaimed academic work here; the award of the Nobel Prize for Economics to Aumann is also a "Jerusalem victory," in a cultural sense.

Aumann's field of research has been game theory - an attractive if rather misleading name, since he does not delve into Monopoly or poker, but rather constructs abstract models that explore how individuals react when they are affected by other peoples' actions.

Game theory first became known to the public when Nash, Harsany and Zelten won the Economics Nobel in 1995 and John Nash's life story became a book and the magnificent Oscar-winning film, "A Beautiful Mind."

Many who ask what Israel Aumann has contributed to economics (not to mention Israel's economy) may be disappointed. It is hard to describe his contributions without slipping into absurd statements. Game theory has not produced cures for incurable diseases or launched missiles to the moon. But it has changed the way in which economists think.

Before Game theory, an economist looked at the world with the assumption that each economic unit accepts prices as givens and reacts to them in optimal fashion. Game theory also assumes that the decision maker (the player, in the language of game theory) acts rationally in the sense that he maximizes a subjective, well-defined cause.

Since the spread of game theory, the economic unit acts strategically: it bases its decisions on examining the moves and considerations of the other players. Aumann played a central role in the revolution of game theory in economics, as one who invented new terms, researched them analytically and recognized the connection between mathematical precision and human wisdom.

Aumann influenced generations of students at Hebrew University. He was a prime mover behind the Center for Rationality. Researchers in economics, computer science, law, psychology, botany, humanities, mathematics, philosophy and psychology meet daily for discussions in the center. The center's success is only due to the boundless natural intellectual curiosity of Aumann and his colleagues.  I know of no other inter-disciplinary center anywhere in the world as successful as this one.

Aumann does not suppress his feelings in his academic work. In a recent lecture, he spoke of his work in game theory: discovering links between concepts ostensibly distant from one another. He also spoke of his love for his late wife Esther. In one of his beautiful essays co-written with Michael Maschler, Aumann dealt with an issue from the Talmud's Ketubot tractate. The article was dedicated to his son Shlomo, "A scholar and a man of the world," who fell in battle in 1982.

Aumann is not a candidate to be governor of the Bank of Israel or strategic adviser to the chief of staff. His specialty is understanding the logic of strategic thought. Some believe that ultimately, this understanding will be translated into the language of the gross domestic product, and others believe game theory has no real value. In any case, the test of academic endeavor is not in its immediate usefulness. Aumann is an academic paragon: a scholar who devotes his life to work, study and teaching for their own sake.

His political opinions are poles apart from my own. Nevertheless, I have often found myself discussing political issues with him, discussing, not arguing. He has always respected the opinions of others and was willing to listen. I found in him tireless faith in the ability to persuade. Aumann is a narrow bridge of understanding between isolated parts of the nation.

When I hear lectures by Israel Aumann, a yeshiva student's voice echoes in my head with devotion, clarity and enthusiasm. His winning the Nobel should not be received pompously, but rather as a reminder of Jerusalem's huge potential as a universal cultural center and as a reflection of the values we derive from Jewish tradition.