The central result of this paper establishes an isomorphism between two types of mathematical structures: "ternary preorders" and "convex topologies." The former are characterized by reflexivity, symmetry and transitivity conditions, and can be interpreted geometrically as ordered betweenness...

We give an introduction to the literature on the epistemic foundations of solution concepts in game theory. Only normal-form games are considered. The solution concepts analyzed are rationalizability, strong rationalizability, correlated equilibrium and Nash equilibrium. The analysis is carried...

The "Harsanyi Doctrine" asserts that differences in individuals' beliefs are to be attributed entirely to differences in information. In its embodiment as a Common Prior assumption it is central to the economics of information and the foundations of game theory. This paper attempts to provide a...

Aumann (1976) put forward a formal definition of common knowledge and used it to prove that two "like minded" individuals cannot "agree to disagree" in the following sense. If they start from a common prior and update the probability of an event E (using Bayes' rule) on the basis of private...

In this paper, we study preferences over Savage acts that map states to opportunity sets. Conditional preferences over opportunity sets may be inconsistent with indirect-utility maximization due to implicit uncertainty about future preferences (preference for flexibility), or to an intrinsic...

This paper contributes to a theory of rational choice under uncertainty for decision-makers whose preferences are exhaustively described by partial orders representing "limited information." Specifically, we consider the limiting case of "Complete Ignorance" decision problems characterized by...

We consider interactive epistemic models where individuals are described by both their "knowledge" and their "beliefs." Three intersubjective consistency conditions are examined: Intersubjective Caution (if an individual believes something to be common belief then he knows it to be common...

We show that Maskin monotone social choice correspondences on sufficiently rich domains satisfy a generalized strategy-proofness property, thus generalizing Muller and Satterthwaite's (1977) theorem to correspondences. <p> From the point of view of Nash implementation theory, the result yields a...</p>

The concept of a strict extended partial order (SEPO) has turned out to be very useful in explaining (resp. rationalizing) non-binary choice functions. The present paper provides a general account of the concept of extended binary relations, i.e., relations between subsets and elements of a...

Within an incomplete information framework (where the primitives are the individuals' belief hierarchies) we investigate the intersubjective implications of the assumption that it is common belief that no individual has any false beliefs (a key component of the Truth Axiom). We consider two...