Document Type
Discussion Paper
Publication Date
12-1-2014
CFDP Number
1973R
CFDP Revision Date
2015-07-01
CFDP Pages
34
Abstract
Consider the following “informational robustness” question: what can we say about the set of outcomes that may arise in equilibrium of a Bayesian game if players may observe some additional information? This set of outcomes will correspond to a solution concept that is weaker than equilibrium, with the solution concept depending on what restrictions are imposed on the additional information. We describe a unified approach encompassing prior informational robustness results, as well as identifying the solution concept that corresponds to no restrictions on the additional information; this version of rationalizability depends only on the support of players’ beliefs and implies novel predictions in classic economic environments of coordination and trading games. Our results generalize from complete to incomplete information the classical results in Aumann (1974, 1987) and Brandenburger and Dekel (1987) which can be (and were) given informational robustness interpretations. We discuss the relation between informational robustness and “epistemic” foundations of solution concepts.
Recommended Citation
Bergemann, Dirk and Morris, Stephen, "Informational Robustness and Solution Concepts" (2014). Cowles Foundation Discussion Papers. 2388.
https://elischolar.library.yale.edu/cowles-discussion-paper-series/2388