BEYOND NASH EQUILIBRIUM: SOLUTION CONCEPTS FOR THE 21ST CENTURY
JOSEPH HALPERN
CORNELL UNIVERSITY
Nash equilibrium is the most commonly used notion of equilibrium in game
theory. However, it suffers from numerous problems. Some are well known
in the game theory community. For example, the Nash equilibrium of
repeated prisoner's dilemma is neither normatively nor descriptively
reasonable. However, new problems arise when considering Nash equilibrium
from a computer science perspective. For example, Nash equilibrium is not
robust (it does not tolerate "faulty" or "unexpected" behavior), it does
not deal with coalitions, it does not take computation cost into account,
and it does not deal with cases where players are not aware of all aspects
of the game. In this talk, I discuss solution concepts that try to
address these shortcomings of Nash equilibrium. This talk represents
joint work with various collaborators, including Ittai Abraham, Danny
Dolev, Rica Gonen, Rafael Pass, and Leandro Rego. No background in game
theory will be presumed.
BIO
Joseph Halpern received a B.Sc. in mathematics from the University of
Toronto in 1975 and a Ph.D. in mathematics from Harvard in 1981. In
between, he spent two years as the head of the Mathematics Department at
Bawku Secondary School, in Ghana. After a year as a visiting scientist at
MIT, he joined the IBM Almaden Research Center in 1982, where he remained
until 1996, also serving as a consulting professor at Stanford. In 1996,
he joined the CS Department at Cornell, and is now the department chair.
Halpern's major research interests are in reasoning about knowledge and
uncertainty, security, distributed computation, decision theory, and game
theory. Together with his former student, Yoram Moses, he pioneered the
approach of applying reasoning about knowledge to analyzing distributed
protocols and multi-agent systems. He has coauthored six patents, two
books ("Reasoning About Knowledge" and "Reasoning about Uncertainty"), and
over 300 technical publications.
Halpern is a Fellow of AAAI, AAAS, ACM, IEEE, and SEAT (Society for the
Advancement of Economic Theory). Among other awards, he received the ACM
SIGART Autonomous Agents Research Award in 2011, the Dijkstra Prize in
2009, the ACM/AAAI Newell Award in 2008, the Godel Prize in 1997, was a
Guggenheim Fellow in 2001-2002, and a Fulbright Fellow in 2001-2002 and
2009-2010. Two of his papers have won best-paper prizes at IJCAI (1985
and 1991), and another two received best-paper awards at the Knowledge
Representation and Reasoning Conference (2006 and 2012). He was the
editor-in-chief of the Journal of the ACM (1997-2003) and has been the
program chair of a number of conferences, including the Symposium on
Theory in Computing (STOC), Logic in Computer Science (LICS), Uncertainty
in AI (UAI), Principles of Distributed Computing (PODC), and Theoretical
Aspects of Rationality and Knowledge (TARK).