Giacomo Bonanno
Working Papers

Giacomo Bonanno,    Logics for belief as maximally plausible possibility.


We consider a basic logic with two primitive uni-modal operators: one for certainty and the other for plausibility. The former is assumed to be a normal operator (corresponding - semantically - to a binary Kripke relation), while the latter is merely a classical operator (corresponding - semantically - to a neighborhood structure). We then define belief, interpreted as ``maximally plausible possibility'', in terms of these two notions: the agent believes A if (1) she cannot rule out A (that is, it is not the case that she is certain that not-A), (2) she judges A to be plausible and (3) she does not judge not-A to be plausible. We consider several interaction properties between certainty and plausibility and study how these properties translate into properties of belief (positive and negative introspection, their converses, conjunction, etc.). We then prove that all the logics considered are minimal logics for the highlighted theorems. We also consider a number of possible interpretations of plausibility and identify the corresponding logics.

  To download the file in pdf format click hereCPB_logic.pdf

Giacomo Bonanno and Elias Tsakas,    Qualitative analysis of common belief of rationality in strategic-form games.


We study common belief of rationality in strategic-form games with ordinal utilities, employing a model of qualitative beliefs. We characterize the three main solution concepts for such games, viz., Iterated Deletion of Strictly Dominated Strategies (IDSDS), Iterated Deletion of Boergers-dominated Strategies (IDBS) and Iterated Deletion of Inferior Strategy Profiles (IDIP), by means of gradually restrictive properties imposed on the models of qualitative beliefs. As a corollary, we prove that IDIP refines IDBS, which refines IDSDS.

  To download the file in pdf format click hereQualitative.pdf

Giacomo Bonanno,   Two lectures on the epistemic foundations of game theory.


These are the slides of  two lectures on the Epistemic Foundations of Game Theory, delivered at the Royal Netherlands Academy of Arts and Sciences (KNAW), February 8, 2007.

                             To download the files in pdf format click here: Lecture 1.pdfLecture 2.pdf

 Giacomo Bonanno (with Klaus Nehring),   Agreeing to disagree: a survey.

                             To download the paper in pdf format click here: agree.pdf

Some of the material in this paper was published in: Giacomo Bonanno and Klaus Nehring, “How to make sense of the common prior assumption under incomplete information", International Journal of Game Theory, 28 (3), August 1999, pp. 409-434 (To download the paper in pdf format click here: common.pdf)