Several recent results on the aggregation of judgments over logically connected propositions show that, under certain conditions, dictatorships are the only propositionwise aggregation functions generating fully rational (i.e., complete and consistent) collective judgments. A frequently mentioned route to avoid dictatorships is to allow incomplete collective judgments. We show that this route d...

In generic perfect-information games the unique Subgame-Perfect Equilibrium (SPE) outcome is identical to the one predicted by several rationalizability notions, like Extensive-Form Rationalizability (EFR), the Backward Dominance Procedure (BDP), and Extensive-Form Rationalizability of the Agent form (AEFR). We show that, in contrast, within the general class of perfect information games all th...

In the present paper, we introduce the fuzzy Nehring axiom, fuzzy Sen axiom and weaker form of the weak fuzzycongruence axiom. We establish interrelations between these axioms and their relation with fuzzy Chernoff axiom. Weexpress full rationality of a fuzzy choice function using these axioms along with the fuzzy Chernoff axiom.

We study rationality in protocol design for the full-information model, a model characterized by computationally unbounded adversaries, no private communication, and no simultaneity within rounds. Assuming that players derive some utility from the outcomes of an interaction, we wish to design protocols that are faithful: following the protocol should be an optimal strategy for every player, for...

Several recent results on the aggregation of judgments over logically connected propositions show that, under certain conditions, dictatorships are the only independent (i.e., propositionwise) aggregation rules generating fully rational (i.e., complete and consistent) collective judgments. A frequently mentioned route to avoid dictatorships is to allow incomplete collective judgments. We show t...

Rationality is a fundamental concept in economics. Most researchers will accept that human beings are not fully rational. Herbert Simon suggested that we are “bounded rational”. However, it is very difficult to quantify “bounded rationality”, and therefore it is difficult to pinpoint its impact to all those economic theories that depend on the assumption of full rationality. Ariel Rubinstein pr...

This paper examines different approaches to rationality in analytic philosophy and AI, in the light of Bermúdez’s proposal that a full account of rationality must aim to explain how agents can both select and explain actions, as well as assessing them against some normative standard. We briefly survey instrumental, linguistic and discursive accounts of rationality, and conjecture that Habermas’...