AN INFORMATIONALLY ROBUST EQUILIBRIUM FOR 2-PERSON NON-ZERO-SUM GAMES

This paper considers the implications of explicit slight uncertainty about the strategic sequence of moves, that is, about the informational structure, for a two-person nonzero-sum game. It is shown that the set of associated informationally robust equilibria must be nonempty and must be a subset of the set of Nash equilibria. Although the present approach is conceptually reminiscent of that underlying perfectness, the two concepts are shown to be logically unrelated. There may exist no equilibrium which is both perfect and informationally robust. (C) 1994 Academic Press, Inc.