Durant les dernières décennies, deux théories a priori contradictoires l’une avec l’autre,prétendent donner un fondement aux comportements des agents économiques. La théorie de la décision axiomatique, la plus ancienne cherche à décrire les comportements à partir du principe de rationalité, alors que l’économie comportementale se base principalement sur une analyse empirique et expérimentale. Cette thèse, prend le parti de réunir ces deux points de vues en mobilisant le concept de préférence incomplète. Leurs fléxibilités capturent de nombreux comportements observés lors des expériences, et leurs structures riches permettent une analyse normative. Dans cette optique, nous développons dans la première partie un modèle d’aversion au risque dynamique, en modélisant la notion de bienêtre par une relation de préférence incomplète. Nous montrons que le bien-être du décideur est représenté par deux psychologies contradictoires. La première traduit l’aversion au risque sur le long terme et, est représentée par le modèle de l’espérance d’utilité, la deuxième décrit une réaction plus émotionnelle face au risque, et est caractérisée par le modèle de l’espérance d’utilité au sens de Choquet. Dans la seconde partie, nous démontrons quelles sont les conditions comportementales, nécessaires et suffisantes permettant à une relation de préférences incomplète d’être représentée par l’intersection d’un ensemble de relation de préférences complètes vérifiant l’axiome de l’indépendance comonotone. / In recent decades, two theories which seems contradictory, claim that they can provide abasis for the behavior of economic agents, i.e the theory of decision and the behavioral economics. We have tried, in this thesis to unite these two points of view by mobilizing the concept of incomplete preference. We develop in the first part a model of time varying risk aversion: we show that the Decision Maker anticipates that the passage of time will have an effect on him outlook. By modeling the notion of well-being with a incomplete preference,we show that the welfare of the decision maker is represented by two contradictory psychologies. The first reflects the risk aversion in the long term and is represented by the model of expected utility, the second describes a more emotional response to risk, and is characterized by the model of Choquet expected utility. In the second part, we identify the behavioral conditions, both necessary and sufficient, in which an incomplete preference relation could be represented by the intersection of a set of complete and transitive preference relation satisfying the axiom of comonotone independence.

Stress and time pressure is more present in todays labor markets. In financial markets a securities broker is forced to take decisions on investments under high cognitive load and under extreme time pressure. The research of decision under risk gained new ground with the development of the prospect theory and gave us new insights to the decision making of men. Prospect theory has shown that people are risk seekers when dealing with loss decisions and risk avert when dealing with profit decisions. The value function are defined over gains and losses. Losses looms larger then gains. Although much research conducted on the decision making under risk no previous research have been done showing how time pressure affects decision at risk by using skin conductance. This paper aimed through a randomized experiment with 23 participants examine how time pressure affects individuals' decisions related to risk. Furthermore, it intends to analyze whether time pressure mediate a possible effect of stress by using skin conductance. The results show that there is an increase in risk aversion for gains. This risk aversion was also statistically significant at the 1% level when each participant's responses were used and almost at 5% level when the mean values from each participant was used. Upon loss a risk -seeking behavior could be noticed but it was not statistically significant at the 5 % level. Stress levels as measured by skin conductance showed that the time-pressed group showed signs of stress. However, no stress data was significant at the 5 % level. / Stress och tidspress är idag allt mer närvarande på arbetsmarknaden. På de finansiella marknaderna kan en värdepappersmäklare tvingas ta beslut om investeringar under hög kognitiv belastning och under en extrem tidspress. Forskningen av beslut under risk har genom prospect theory gett oss nya insikter om vilka beslut vi människor tar. Prospect theory har visat att människor är risksökande vid förlustfrågor och riskaversiva vid vinstfrågor. Prospect theorys värdefunktion är definierad över vinst och förlust. Förluster väger tyngre än vinster. Trots att mycket forskning genomförts på beslut vid risk har ingen tidigare forskning hur tidspress påverkar beslut vid risk med hjälp av hudkonduktans tidigare genomförts. Denna uppsats hade som mål att genom ett randomiserat experiment med 23 deltagare undersöka hur tidspress påverkar individers beslut kopplade till risk. Vidare är syftet att också analysera om upplevd stress medierar en eventuell effekt av tidspress genom att använda hudkonduktans. Resultatet visar att det finns en ökad riskaversion vid vinstfrågor. Denna riskaversion var även statistiskt säkerställd på 1% nivå när varje deltagares svar användes och nästan på 5% nivå då medelvärden från varje deltagare användes. Vid förlustfrågor fanns ett risksökande beteende men den var ej statistiskt säkerställd på 5% nivå. Stressnivåerna som uppmättes med hudkonduktans visade att den tidspressade gruppen blev stressade. Dock var inga stressdata signifikanta på 5% nivå.

This dissertation focuses on robust coalition formation between selfish agents in a dynamic environment where contracts are unenforceable. Previous research on this topic has covered each different aspect of this problem, but no research successfully addresses these factors in combination. Therefore, a novel approach is required. This dissertation accordingly has three major goals: to develop a theoretical framework that describes how selfish agents should select jobs and partners in a dynamic, contractless environment, to test a strategy based on that framework against existing heuristics in a simulated environment, and to create a learning agent capable of optimally adjusting its coalition formation strategy based on the level of dynamic change found in its environment. Experimental results demonstrate that the Expected Utility (EU) strategy based on the developed theoretical framework performs better than strategies using heuristics to select jobs and partners, and strategies which simulate a centralized “manager”. Future work in this area includes altering the EU strategy from an anytime strategy to a hill-climbing one, as well as further game theoretic explorations of the interactions between different strategies. / text

L'objectif central de cette thèse est d'étudier le comportement de fraude fiscale des contribuables quand ils ne déclarent qu'une partie de leur revenu. Le premier chapitre complète la littérature existante en étudiant le niveau de déclaration du revenu et les effets de changements des taux de taxe, de pénalité et de probabilité de contrôle, en considérant des fonctions d'imposition et de pénalité non linéaire, dans le cadre de la théorie de l'espérance de l'utilité.Le cadre fourni par la théorie des perspectives cumulatives est ensuite utilisé dans le second chapitre. L'accent est mis sur la dépendance des décisions du contribuable vis-à-vis du revenu de référence introduit par cette théorie. Le troisième chapitre caractérise le barème optimal d'imposition du revenu et la stratégie de contrôle et de pénalité que doit mettre en place l'État quand le comportement de fraude des contribuables vérifie les propriétés de la théorie des perspectives. / This dissertation analyzes the tax evasion behavior of taxpayers when they do not declare their entire income. The first chapter studies the declaration of the taxpayer and the effects of changes in the tax rate, the penalty rate and the probability of audit. The tax and the penalty functions are assumed to be non linear. The setting is provided by expected utility theory. The setting provided by cumulative prospect theory is used in the second chapter. Reference dependence, which is a central point in this theory, is particularly studied. The third chapter characterizes the optimal income tax and audit schemes under taxe evasion behavior, when of tax payers behave as predicted by prospect theory.

ELABORATIONS ON MULTIATTRIBUTE UTILITY THEORY DOMINANCE By David L. Vairo A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Virginia Commonwealth University, 2019. Major Director: Dissertation director’s name, Dr. Jason Merrick, Supply Chain Management and Analytics Multiattribute Utility Theory (MAUT) is used to structure decisions with more than one factor (attribute) in play. These decisions become complex when the attributes are dependent on one another. Where linear modeling is concerned with how factors are directly related or correlated with each other, MAUT is concerned with how a decision maker feels about the attributes. This means that direct elicitation of value or utility functions is required. This dissertation focuses on expanding the types of dominance forms used within MAUT. These forms reduce the direct elicitation needed to help structure decisions. Out of this work comes support for current criticisms of gain/loss separability that is assumed as part of Prospect Theory. As such, an alternative to Prospect Theory is presented, derived from within MAUT, by modeling the probability an event occurs as an attribute.

A wager is a one time bet, staking money on one among a collection of alternatives having uncertain reward. Wagers represent a common class of engineering decision, where “bets” are placed on the design, deployment, and/or operation of technology. Often such wagers are characterized by alternatives having value that evolves according to some future cash flow. Here, the values of specific alternatives are derived from a cash flow modeled as a stochastic marked point process. A principal difficulty with these engineering wagers is that the probability laws governing the dynamics of random cash flow typically are not (completely) available; hence, separating the gambler’s preference among wager alternatives is quite difficult. In this dissertation, we investigate a computational approach for separating preferences among alternatives of a wager where the alternatives have values that evolve according to a marked point processes. We are particularly concerned with separating a gambler’s preferences when the probability laws on the available alternatives are not completely specified.

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With the rise of powerful mobile devices and the broad availability of computing power, Automatic Speech Recognition is becoming ubiquitous. A flawless ASR system is still far from existence. Because of this, interactive applications that make use of ASR technology not always recognize speech perfectly, when not, the user must be engaged to repair the transcriptions. We explore a rational user interface that uses of machine learning models to make its best effort in presenting the best repair strategy available to reduce the time in spent the interaction between the user and the system as much as possible. A study is conducted to determine how different candidate policies perform and results are analyzed. After the analysis, the methodology is generalized in terms of a decision theoretical framework that can be used to evaluate the performance of other rational user interfaces that try to optimize an expected cost or utility.

A transformative decision rule alters the representation of a decisionproblem, either by changing the sets of acts and states taken intoconsideration, or by modifying the probability or value assignments.Examples of decision rules belonging to this class are the principleof insufficient reason, Isaac Levi’s condition of E-admissibility, Luceand Raiffa’s merger of states-rule, and the de minimis principle. Inthis doctoral thesis transformative decision rules are analyzed froma foundational point of view, and applied to two decision theoreticalproblems: (i) How should a rational decision maker model a decisionproblem in a formal representation (‘problem specification’, ‘formaldescription’)? (ii) What role can transformative decision rules play inthe justification of the principle of maximizing expected utility?The thesis consists of a summary and seven papers. In Papers Iand II certain foundational issues concerning transformative decisionrules are investigated, and a number of formal properties of this classof rules are proved: convergence, iterativity, and permutability. InPaper III it is argued that there is in general no unique representationof a decision problem that is strictly better than all alternative representations.In Paper IV it is shown that the principle of maximizingexpected utility can be decomposed into a sequence of transformativedecision rules. A set of axioms is proposed that together justify theprinciple of maximizing expected utility. It is shown that the suggestedaxiomatization provides a resolution of Allais’ paradox that cannot beobtained by Savage-style, nor by von Neumann and Morgenstern-styleaxiomatizations. In Paper V the axiomatization from Paper IV is furtherelaborated, and compared to the axiomatizations proposed byvon Neumann and Morgenstern, and Savage. The main results in PaperVI are two impossibility theorems for catastrophe averse decisionrules, demonstrating that given a few reasonable desiderata for suchrules, there is no rule that can fulfill the proposed desiderata. In PaperVII transformative decision rules are applied to extreme risks, i.e.to a potential outcome of an act for which the probability is low, butwhose (negative) value is high. / <p>QC 20100622</p>

Cette thèse appartient au domaine de la théorie de la décision en situation d'incertitude. Elle vise à comprendre, décrire, et représenter les choix individuels dans différents contextes de décision. Notre travail se concentre sur le fait que le comportement économique est souvent influencé par la structure et le déroulement de la résolution de l'incertitude. Dans une première expérience nous avons confronté nos sujets à différents types d'incertitude – à savoir du risque (probabilités connues), de l'incertain (probabilités inconnues), du risque composé et de l'incertain composé – en utilisant des mécanismes aléatoires particuliers. Le chapitre 1 analyse l'hétérogénéité des attitudes individuelles face à l'ambiguïté, au risque composé et à l'incertain composé alors que dans le chapitre 2, le modèle d'espérance d'utilité à dépendance du rang est utilisé comme outil de mesure afin d'étudier en détails ces attitudes au niveau individuel. Le chapitre 3 confronte à l'expérience l'interprétation de l'ambiguïté en terme de croyances de second ordre et propose une méthode d'élicitation de la fonction qui caractérise l'attitude face à l'ambiguïté dans les modèles « récursifs » de décision face à l'incertain. La seconde partie de la thèse s'intéresse aux comportements de décision individuelle dans un contexte dynamique et est composée de deux études expérimentales indépendantes. Néanmoins, elles reposent toutes deux sur la décomposition de l'axiome d'indépendance en trois axiomes dynamiques: conséquentialisme, cohérence dynamique et réduction des loteries composées. Le chapitre 4 rapporte les résultats d'une expérience de décision individuelle sur les facteurs de violations de chacun de ces axiomes. Le chapitre 5 présente une catégorisation conceptuelle des comportements individuels dans des problèmes de décision séquentiels face au risque. Le cas des agents ne se conformant pas à l'axiome d'indépendance y est étudié de façon systématique et les résultats d'une expérience spécialement conçue pour tester cette catégorisation sont présentés. / This thesis belongs to the domain of decision theory under uncertainty and aims to understand, describe and represent individual choices in various decision contexts. Our work focuses on the fact that economic behavior is often influenced by the structure and the timing of resolution of uncertainty. In a first experimental part, we confronted subjects with different types of uncertainty, namely risk (known probabilities), uncertainty (unknown probabilities), compound risk and compound uncertainty, which were generated using special random devices. In chapter 1 we analyze the heterogeneity of attitudes towards ambiguity, compound risk and compound uncertainty whereas in chapter 2, we use rank dependent expected utility as a measuring tool in order to individually investigate these attitudes. Chapter 3 confronts the interpretation of ambiguity in term of second order beliefs with the experimental data and proposes a method for eliciting the function that encapsulates attitudes toward ambiguity in the “recursive” or multistage models of decision under uncertainty. The second part of the thesis deals with individual decision making under risk in a dynamic context and is composed of two independent experimental studies. Both of them rely on the decomposition of the independence axiom into three dynamic axioms: consequentialism, dynamic consistency and reduction of compound lotteries. Chapter 4 reports experimental data about violations of each of the three axioms. Chapter 5 presents a conceptual categorization of individual behavior in sequential decision problems under risk, especially those which do not conform to the independence axiom. We propose an experiment specially designed to test the predictions of this categorization.