Risk Attitudes and Measures of Value for Risky Lotteries.

The topic of this thesis is decision-making under risk. I focus my analysis on expected utility theory by von Neumann and Morgenstern. I am especially interested in modeling risk attitudes represented by Bernoulli utility functions that belong to the following classes: Constant Absolute Risk Aversion, Decreasing Absolute Risk Aversion (understood as strictly decreasing) and in particular a subset thereof - Constant Relative Risk Aversion. I build a theory of buying and selling price for a lottery, the concepts defined by Raiffa, since such theory proves useful in analyzing a number of interesting issues pertaining to risk attitudes' characteristics within expected utility model. In particular, I analyze the following: - Chapter 2 - expected utility without consequentialism, buying/selling price gap, preference reversal, Rabin paradox - Chapter 3 - characterization results for CARA, DARA, CRRA, simple strategies and an extension of Pratt result on comparative risk aversion - Chapter 4 - riskiness measure and its intuition, extended riskiness measure and its existence, uniqueness and propertiesdecision-making under risk; lottery; gamble; expected utility theory; risk attitudes; CARA; DARA; CRRA; buying and selling price for a lottery; D81; D03; C91;Decision making; Strategic planning; Risk-taking (Psychology);

Sender-Receiver Games

Standard game-theoretic solution concepts do not guarantee meaningful commu- nication in cheap-talk games. In this paper, we define a solution concept which guarantees communication for a large class of games by designing a behavior pro- tocol which the receiver uses to judge messages sent by the sender on acceptability. For that, we will make use of the Nash equilibrium concept for which truth-telling is a consequence. Uniqueness is nevertheless not a consequence, but after reasonable selection it is. Further, we will come to a method to compute all equilibria very easily

Using automata to characterise fixed point temporal logics

This work examines propositional fixed point temporal and modal logics called mu-calculi and their relationship to automata on infinite strings and trees. We use correspondences between formulae and automata to explore definability in mu-calculi and their fragments, to provide normal forms for formulae, and to prove completeness of axiomatisations. The study of such methods for describing infinitary languages is of fundamental importance to the areas of computer science dealing with non-terminating computations, in particular to the specification and verification of concurrent and reactive systems. To emphasise the close relationship between formulae of mu-calculi and alternating automata, we introduce a new first recurrence acceptance condition for automata, checking intuitively whether the first infinitely often occurring state in a run is accepting. Alternating first recurrence automata can be identified with mu-calculus formulae, and ordinary, non-alternating first recurrence automata with formulae in a particular normal form, the strongly aconjunctive form. Automata with more traditional Büchi and Rabin acceptance conditions can be easily unwound to first recurrence automata, i.e. to mu-calculus formulae. In the other direction, we describe a powerset operation for automata that corresponds to fixpoints, allowing us to translate formulae inductively to ordinary Büchi and Rabin-automata. These translations give easy proofs of the facts that Rabin-automata, the full mu-calculus, its strongly aconjunctive fragment and the monadic second-order calculus of n successors SnS are all equiexpressive, that Büchi-automata, the fixpoint alternation class Pi_2 and the strongly aconjunctive fragment of Pi_2 are similarly related, and that the weak SnS and the fixpoint-alternation-free fragment of mu-calculus also coincide. As corollaries we obtain Rabin's complementation lemma and the powerful decidability result of SnS. We then describe a direct tableau decision method for modal and linear-time mu-calculi, based on the notion of definition trees. The tableaux can be interpreted as first recurrence automata, so the construction can also be viewed as a transformation to the strongly aconjunctive normal form. Finally, we present solutions to two open axiomatisation problems, for the linear-time mu-calculus and its extension with path quantifiers. Both completeness proofs are based on transforming formulae to normal forms inspired by automata. In extending the completeness result of the linear-time mu-calculus to the version with path quantifiers, the essential problem is capturing the limit closure property of paths in an axiomatisation. To this purpose, we introduce a new \exists\nu-induction inference rule

Second-Order Logic and Related Systems : a game-semantical perspective (Mathematical Logic and its Applications)

This is based on tutorial lectures on second-order logic in SAML 2022. Among others, we here discuss monadic second-order logic (MSO) from a game-theoretical view-point. Although the validity of MSO in terms of standard structures is not decidable (not axiomatizable), the MSO theory of full binary tree is decidable and modal μ-calculus can be viewed as a decidable fragment of MSO

Are Voters Cursed When Politicians Conceal Policy Preferences?

In campaigns, candidates often avoid taking positions on issues, concealing the policy preferences that would guide them if elected. This paper describes a novel explanation for ambiguity in political campaigns. It develops a model of candidate competition in which policy-motivated candidates can choose whether or not to announce their policy preferences to voters. It applies Eyster and Rabin\u27s (2005) concept of cursed equilibrium, which allows for varying degrees of understanding of the connection between type (policy preference) and strategy (whether to announce). If voters updated according to Bayes\u27 Rule, they would understand that candidates who do not announce positions are strategically concealing an unpopular policy preference. In equilibrium, only the most extreme candidates, those located furthest from the median voter’s position, would choose to take no position. However, if voters do not sufficiently appreciate the informational content of a non-announcement, unraveling will not occur and both extremists and more moderate candidates will not announce positions

Public key cryptography in resource-constrained WSN

In this paper we present a detailed review of the works on public key cryptography (PKC) in wireless sensor networks (WSNs). In the early days of sensor networks, public key cryptography was thought to be completely unfeasible considering its computational complexity and energy requirements. By this time, several works have proved that the lightweight versions of many well-known public key algorithms can be utilized in WSN environment. With the expense of a little energy, public key based schemes could in fact be the best choice for ensuring data security in high-security demanding WSN applications. Here, we talk about the notion of public key cryptography in WSN, its applicability, challenges in its implementation, and present a detailed study of the significant works on PKC in WSN

Economic action and reference points : an experimental analysis /

Consultable des del TDXA portada: International Doctorate in Economic AnalysisTítol obtingut de la portada digitalitzadaAquesta tesi analitza diversos aspectes de les motivacions individuals i de les seves implicacions en processos econòmics. Específicament, analitzo en detall criteris normatius que poden aplicar els individus com són els de justícia i reciprocitat. En la Introducció defineixo l'ús que en faig de conceptes com la reciprocitat, la justícia, la «dependència del menú» i els «punts de referència» donat que s'empren en el desenvolupament dels diferents capítols. També es descriu la metodologia emprada, que consisteix en alguns models teòrics sobre el comportament dels individus en situacions estratègiques, incorporant elements de la Teoria dels Jocs i l'ús de la metodologia experimental. En el segon capítol, « El concepte de justícia de Rabin i la provisió privada de béns públics», analitzo en detall les implicacions de la teoria de Rabin (1993) sobre el comportament estratègic d'individus. Aquest model introdueix en la funció d'utilitat , a més dels pagaments econòmics que un individu obté, aspectes psicològics com el sentit de justícia en les relacions econòmiques amb altres individus. En aquest capítol examino les implicacions d'una extensió de la teoria a un camp a on existeix una acumulació de resultats experimentals en contradicció amb el comportament predit pels models estàndard de la teoria dels jocs. Mostro que la teoria d'en Rabin és consistent amb el que s'anomena «splitting» però inconsistent amb el que es coneix com a «efecte MPCR». El tercer capítol, «Punts de referència i reciprocitat negativa en jocs seqüencials simples», analitza la influència que poden tenir certs vectors de pagaments no disponibles en un moment de decisió, anomenats «punts de referència», sobre la preferència per un altre conjunt de vectors de pagaments. Això es connecta amb l'atribució de certes intencions a altres subjectes quan trien determinats cursos d'acció en el joc. Mitjançant la utilització d'experiments s'obtenen resultats que confirmen la importància dels punts de referència en les consideracions de reciprocitat que empren els individus. El quart capítol, « Aspectes distribucionals i els punts de referència», analitza alguns aspectes que poden combinar-se amb els punts de referència en la atribució d'intencions. Aquests aspectes són: el pagament que podia rebre un agent en el punt de referència, el seu pagament relatiu a l'altre agent i, finalment, el pagament conjunt que podien obtenir els dos agents en el punt de referència. Els resultats experimentals obtinguts mostren que cap d'aquests efectes pot explicar per ell mateix els resultats. Finalment, el cinquè capítol, « Els joc del dilema dels presoners en forma seqüencial: Reciprocitat i efectes de dimensió del grup» estudia les reaccions dels individus a certes decisions d'altres individus del procés i els canvis d'aquestes reaccions amb la dimensió del grup. Els resultats experimentals obtinguts , mostren que el comportament observat és consistent amb consideracions de reciprocitat i d'aversió a la desigualtat.This thesis analyzes several aspects of the motivations that drive individuals and their implications in economic processes. In particular, I analyze in detail normative criteria that individuals apply such as those of fairness and reciprocity. In the Introduction I define the use I make of the concepts of reciprocity, fairness, menu dependence and reference points that will be used in the course of the different chapters. The methodology developed in this thesis employs some theoretical models on the behavior of individuals in strategic interactions, using elements of Game Theory and Experimental Economics. In the second chapter, «On Rabin's Concept of Fairness and the Private Provision of Public Goods», I analyze in detail the implications of Rabin's (1993) theory of individual behavior and its implications. This model introduces, apart from the economic payoffs that the individual obtains in a strategic interaction, psychological phenomena, mainly a sense of fairness in the relation with other agents. In this chapter I analyze the implications of an extended version of this theory to a field where there exists a vast amount of experimental evidences contradicting the behavior predicted by standard game theoretical models. I show that Rabin's theory is consistent with one piece of evidence repeatedly found in experiments, the so call «splitting». I also show that the model is inconsistent with another piece of evidence in the field, the «MPCR effect». The third chapter, «Reference Points and Negative Reciprocity in Simple Sequential Games», analyzes the influence that certain payoff vectors, the «reference points», not attainable at that time, may have on the preference by other payoff vectors. This is connected with the attribution of certain intentions to the other players when selecting some courses of action. By using experiments I obtain results that confirm the importance of these reference points in the reciprocity considerations that individuals apply. Chapter four , «Distributional Concerns and Reference Points», analyzes some aspects that may interact with the reference points in the attributions of intentions. These aspects are the payoff to the agent from a given course of action, his/her relative payoff and the joint payoff. The experimental results show that none of these elements is able to explain by itself the results. Finally, the fifth chapter, «The Sequential Prisoner's Dilemma Game: Reciprocity and Group Size Effects» analyzes how aspects of the individual motivations interact with social aspects. In particular it studies how the reactions of individuals change with the dimension of the group in certain processes. The experimental results obtained show that in the prisoner's dilemma game (two-person and three-person games) the behavior of subjects may be consistent with reciprocity considerations and with inequality aversion considerations

Randomness versus non-determinism in distributed computing

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1995.Includes bibliographical references (p. 209-214) and index.by Alain Isaac Saias.Ph.D