In (Bonanno, Int J Game Theory 42:567–592, 2013) a general notion of perfect Bayesian equilibrium (PBE) for extensive-form games was introduced and shown to be intermediate between subgame-perfect equilibrium and sequential equilibrium. Besides sequential rationality, the ingredients of the proposed notion are (1) the existence of a plausibility order on the set of histories that rationalizes the given assessment and (2) the notion of Bayesian consistency relative to the plausibility order. We show that a cardinal property of the plausibility order and a strengthening of the notion of Bayesian consistency provide necessary and sufficient conditions for a PBE to be a sequential equilibrium.

This textbook incorporates the author’s previous book "The Economics of Uncertainty and Insurance" and extends it with the addition of several new chapters on risk sharing, asymmetric information, adverse selection, signaling and moral hazard. It provides a comprehensive introduction to the analysis of economic decisions under uncertainty and to the role of asymmetric information in contractual relationships. It is richly illustrated with 150 figures. It is suitable for both self-study and as the basis for an upper-division undergraduate course. The book is written to be accessible to anyone with minimum knowledge of calculus, in particular the ability to calculate the (partial) derivative of a function of one or two variables. The book contains a total of 150 fully solved exercises.

In an earlier paper [Rational choice and AGM belief revision, Artificial Intelligence, 2009] a correspondence was established between the choice structures of revealed-preference theory (developed in economics) and the syntactic belief revision functions of the AGM theory (developed in philosophy and computer science). In this paper we extend the re-interpretation of (a generalized notion of) choice structure in terms of belief revision by adding: (1) the possibility that an item of “information” might be discarded as not credible (thus dropping the AGM success axiom) and (2) the possibility that an item of information, while not accepted as fully credible, may still be “taken seriously” (we call such items of information “allowable”). We establish a correspondence between generalized choice structures (GCS) and AGM belief revision; furthermore, we provide a syntactic analysis of the proposed notion of belief revision, which we call filtered belief revision.

We consider decision problems under complete ignorance and extend the minimax regret principle to situations where, after taking an action, the decision maker does not necessarily learn the state of the world. For example, if the decision maker only learns what the outcome is, then all she knows is that the actual state is one of the (possibly several) states that yield the observed outcome under the chosen action. We refer to this situation as imperfect ex-post information. We show that, given a choice between more information and less information, the decision maker prefers the latter. We also extend the framework to encompass the possibility of less than the extreme degree of pessimism that characterizes the minimax regret criterion.

We investigate an extension of the notion of backward induction to dynamic games with imperfect information and provide a doxastic characterization of it. Extensions of the idea of backward induction were proposed by Penta (2009) and later by Perea (2014), who also provided a doxastic characterization in terms of the notion of common belief of future rationality. The characterization we propose, although differently formulated, is conceptually the same as Perea's and so is the generalization of backward induction. The novelty of this contribution lies in the models that we use, which are dynamic, behavioral models where strategies play no role and the only beliefs that are specified are the actual beliefs of the players at the time of choice. Thus players' beliefs are modeled as temporal, rather than conditional, beliefs and rationality is defined in terms of actual choices, rather than hypothetical plans.

This text provides an introduction to the topic of rational decision making as well as a brief overview of the most common biases in judgment and decision making. "Decision Making" is relatively short (300 pages) and richly illustrated with approximately 100 figures. It is suitable for both self-study and as the basis for an upper-division undergraduate course in judgment and decision making. The book is written to be accessible to anybody with minimum knowledge of mathematics (high-school level algebra and some elementary notions of set theory and probability, which are reviewed in the book). At the end of each chapter there is a collection of exercises that are grouped according to that chapter’s sections. Complete and detailed answers for each exercise are given in the last section of each chapter. The book contains a total of 121 fully solved exercises.

In an earlier paper [Rational choice and AGM belief revision, Artificial Intelligence, 2009] a correspondence was established between the set-theoretic structures of revealed-preference theory (developed in economics) and the syntactic belief revision functions of the AGM theory (developed in philosophy and computer science). In this paper we extend the re-interpretation of those structures in terms of one-shot belief revision by relating them to the trichotomous attitude towards information studied in Garapa (Rev Symb Logic, 1–21, 2020) where information may be either (1) fully accepted or (2) rejected or (3) taken seriously but not fully accepted. We begin by introducing the syntactic notion of filtered belief revision and providing a characterization of it in terms of a mixture of both AGM revision and contraction. We then establish a correspondence between the proposed notion of filtered belief revision and the above-mentioned set-theoretic structures, interpreted as semantic partial belief revision structures. We also provide an interpretation of the trichotomous attitude towards information in terms of the degree of implausibility of the information.

This text provides an introduction to the analysis of economic decisions under uncertainty, with particular focus on insurance markets.