Abstract

The concept of "strategic equilibrium," where each player's strategy is optimal against those of the other players, was introduced by John Nash in his Ph.D. thesis in 1950. Throughout the years, Nash equilibrium has had a most significant impact in economics and many other areas. However, more than 60 years later, its dynamic foundations - how are equilibria reached in long-term interactions - are still not well established.

 In this talk we will overview a body of work of the last decade on dynamical systems in multi-player environments.  On the one hand, the natural informational restriction that each participant may not know the payoffs and utilities of the other participants - "uncoupledness" - turns out to severely limit the possibilities to converge to Nash equilibria.  On the other hand, there are simple adaptive heuristics - such as "regret matching" - that lead in the long run to correlated equilibria, a concept that embodies full rationality. We will also mention connections to behavioral and neurobiological studies, to computer science concepts, and to engineering applications.

 Biography

Sergiu Hart is the Kusiel-Vorreuter University Professor, Professor of Mathematics, and Professor of Economics, at the Hebrew University of Jerusalem. From 1991 to 1998 he was the founding director of the highly reputed Center for the Study of Rationality.

Besides game theory and economic theory, he has contributions in mathematics, computer science, probability and statistics. He is known for studies of strategic foundations of cooperation; strategic use of information in long-term interactions ("repeated games"); adaptive and evolutionary dynamics, particularly with boundedly rational agents; perfect economic competition and its relations to models of fair distribution; and riskiness.

He is Fellow of the Econometric Society and Member of the Israel Academy of Sciences and Humanities. In 1998 he received the Rothschild Prize. He served as president of the Israel Mathematical Union in 2005-2006, and as president of the Game Theory Society in 2008-2010.