An Epistemic Characterization of Extensive Form Rationalizability
نویسندگان
چکیده
We use an extensive form, universal type space to provide the following epistemic characterization of extensive form rationalizability. Say that player i strongly believes event E if i is certain of E conditional on each of her information sets consistent with E. Our main contribution is to show that a strategy profile s is extensive form rationalizable if and only if there is a state in which s is played and (0) everybody is rational, (1) everybody strongly believes (0), (2) everybody strongly believes (0) & (1), (3) everybody strongly believes (0) & (1) & (2), . . . . This result also allows us to provide sufficient epistemic conditions for the backward induction outcome and to relate extensive form rationalizability and conditional common certainty of rationality.
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