On rationalizability in extensive games

This paper analyzes Pearce's notion of extensive form rationalizability (EFR). Although EFR was originally defined as a reduction procedure, this paper shows that it can be characterized in terms of restrictions on players' updating systems. These restrictions correspond to a common hierarchy of nested hypotheses. Next the relationship of EFR to more familiar reduction procedures is examined. In generic games of perfect information, EFR is realization-equivalent to iterated weak dominance and backward induction. Equivalence with iterated weak dominance is complete in the subset of games with ''iterated perfect information.'' Journal of Economic Literature Classification Number: C72. (C) 1997 Academic Press.