A characterization of sequential equilibrium in terms of AGM belief revision

In [G. Bonanno, Rational choice and AGM belief revision, Artificial Intelligence, 2009] a semantics for one-stage AGM belief revision was proposed based on choice frames, borrowed from the rational choice literature. In this paper we extend the semantics of choice frames to deal with iterated belief revision and use the corresponding structures to analyze extensive-form games. Choice frames can be used to represent a player's initial beliefs and disposition to change those beliefs when informed that it is her turn to move. If the frame satisfies AGM-consistency and a natural postulate for iterated belief revision, then it is rationalizable by a total pre-order on the set of histories. We show that three properties of this total pre-order, together with the hypothesis of agreement among players, provide a characterization of the notion of consistent assessment, which is the central component of the notion of sequential equilibrium proposed by Kreps and Wilson [Econometrica, 1982].Choice function, AGM belief revision, extensive-form game, sequential equilibrium, iterated belief revision, backward induction.

Semantic structures for one-stage and iterated belief revision

Semantic structures for belief revision and iterated belief revision are proposed. We start with one-stage revision structures that generalize the notion of choice function from rational choice theory. A correspondence between these one-stage structures and AGM belief revision functions is established. We then add branching time and consider more general structures that accommodate iterated revision. AGM temporal belief revision structures are defined and a syntactic axiomatization is provided

Revealed preference, iterated belief revision and dynamic games

In previous work (G. Bonanno, Rational choice and AGM belief revision, Artificial Intelligence, 2009) a semantics for AGM belief revision was proposed based on choice frames, borrowed from the rational choice literature. In this paper we discuss how to use choice frames to analyze extensive-form games. Given an extensive form with perfect recall, a choice frame can be used to represent a player\u27s initial beliefs and her disposition to change those beliefs when she is informed that it is her turn to move. When some players move more than once along some play of the game, the issue of iterated belief revision arises. We provide a semantics for iterated belief revision in terms of choice frames and provide an outline of how to use choice frames to analyze solution concepts for extensive-form games

Why Rationality May Be a Consequence of Hume's Theory of Choice

Facing R. Sugden's criticism of our interpretation, it is shown in this paper that rationality appears as a possible consequence of Hume's theory of choice. We first argue that Sugden's dismissal of the preference relation from the type of rationality through which Hume's theory is apprehended, is highly disputable, from the point of view of both standard choice theory and Hume's theory of passions. Nonetheless, Sugden's criterion of rationality might be restated in Humean terms as a condition of non-revision of preferences in the dynamics of passions. But, since the process of choice that we have described explicitly takes into account the revision of preferences, and shows that, when this last is no longer required, rationality occurs as an outcome of this process, it is not really concerned by Sugden's criticism.Hume; rationality; decision; passion; desire; preference; will; choice; rationalité; décision; désir; préférence; volonté; choix

Investing in Biogas: Timing, Technological Choice and the Value of Flexibility from Inputs Mix

In a continuous-time framework we study the technology and investment choice problem of a continuous co-digestion biogas plant dealing with randomly fluctuating relative convenience of input factor costs. Input factors enter into the productive process together mixed according to a given initial rule. Being inputs relative convenience stochastically evolving, a successive revision of the initial rule may be desirable. Hence, when the venture starts the manager may or may not install a flexible technology allowing for such option. Investment is irreversible and flexibility is costly. The problem is solved determining in the light of future prospects the optimal revision and then playing backward fixing the investment timing rule.Factor Proportions, Technological Choice, Flexibility, Real Options, Alternative Energy Source

Investing in Biogas: Timing, Technological Choice and the Value of Flexibility from Inputs Mix

In a continuous-time framework we study the technology and investment choice problem of a continuous co-digestion biogas plant dealing with randomly fluctuating relative convenience of input factor costs. Input factors enter into the productive process together mixed according to a given initial rule. Being inputs relative convenience stochastically evolving, a successive revision of the initial rule may be desirable. Hence, when the venture starts the manager may or may not install a flexible technology allowing for such option. Investment is irreversible and flexibility is costly. The problem is solved determining in the light of future prospects the optimal revision and then playing backward fixing the investment timing rule.factor proportions, technological choice, flexibility, real options, alternative energy source

Periods of abelian differentials and dynamics

Given a closed oriented surface S we describe those cohomology classes which appear as the period characters of abelian differentials for some choice of complex structure on S consistent with the orientation. The proof is based upon Ratner's solution of Raghunathan's conjecture.Comment: A revision of my 2000 preprin