This thesis is an examination of the traveler’s dilemma and its backward induction argument. I begin by explaining relevant terminology, the prisoner’s dilemma, and the iterated prisoner’s dilemma; the discussion of which aids my examination of the traveler’s dilemma and its backward induction argument. My evaluation of the traveler’s dilemma involves a dissection of the game into its different components, a presentation of the salient similarities and differences between the traveler’s dilemma and the prisoner’s dilemma, and the exploration of three possible solutions. The first two solutions are adapted from ones initially created to solve other backward induction argument problems. The third solution is original and its foundation rests on the unique structure of the traveler’s dilemma. I focus on this third solution and consider several objections to it. I end this thesis with some ancillary comments about the possibility of generalizing the third solution to other backward induction argument problems. / February 2008

This thesis is an examination of the traveler’s dilemma and its backward induction argument. I begin by explaining relevant terminology, the prisoner’s dilemma, and the iterated prisoner’s dilemma; the discussion of which aids my examination of the traveler’s dilemma and its backward induction argument. My evaluation of the traveler’s dilemma involves a dissection of the game into its different components, a presentation of the salient similarities and differences between the traveler’s dilemma and the prisoner’s dilemma, and the exploration of three possible solutions. The first two solutions are adapted from ones initially created to solve other backward induction argument problems. The third solution is original and its foundation rests on the unique structure of the traveler’s dilemma. I focus on this third solution and consider several objections to it. I end this thesis with some ancillary comments about the possibility of generalizing the third solution to other backward induction argument problems.

This thesis is an examination of the traveler’s dilemma and its backward induction argument. I begin by explaining relevant terminology, the prisoner’s dilemma, and the iterated prisoner’s dilemma; the discussion of which aids my examination of the traveler’s dilemma and its backward induction argument. My evaluation of the traveler’s dilemma involves a dissection of the game into its different components, a presentation of the salient similarities and differences between the traveler’s dilemma and the prisoner’s dilemma, and the exploration of three possible solutions. The first two solutions are adapted from ones initially created to solve other backward induction argument problems. The third solution is original and its foundation rests on the unique structure of the traveler’s dilemma. I focus on this third solution and consider several objections to it. I end this thesis with some ancillary comments about the possibility of generalizing the third solution to other backward induction argument problems.

Consumers frequently face mismatch risk as goods they purchase may be deemed inappropriate or below expectations. Due to this risk, consumers may avoid purchasing such goods and consequently hurt retailers. Can the emergence of peer-to-peer (P2P) marketplaces benefit retailers? On the one hand, P2P marketplaces can mitigate some of this risk by allowing consumers to trade mismatched goods. On the other hand, P2P marketplaces impose a threat on retailers as they compete with them over consumers. We develop a two-period model that highlights the effects introduced by P2P marketplaces. We show that a P2P marketplace benefits both the retailer and consumers when the wholesale price is sufficiently high and hurts them both when the wholesale price is low. The introduction of a P2P marketplace can relieve consumers from the mismatch risk and induces the retailer to post a higher price. However, when the wholesale price is low, the platform manages to extract most, or all, of the consumers surplus and directly hurts consumers, and eventually the retailer who experiences lower sales in both periods. With a high wholesale price the P2P marketplace is limited in its ability of extracting consumer surplus, which increases the retailer sales and benefits both the retailer and consumers. We further observe that social welfare is generally higher unless the wholesale price is relatively low.

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This thesis compares forward neural networks with algorithms using game theory on basis of board game Blokus. The theoretical introduction part describes the characteristics of neural networks and work with them. There is also outlined algorithm of game theory. The second part deals about the implementation of players based on the outlined principles  and shortly descriptions GUI of application. In conclusion, the differences between the players  are evaluated on the charts created on the performed tests.

Cette thèse porte sur la modélisation des comportements individuels de vaccination. Lorsque la vaccination est libre, les individus peuvent décider ou non de se vacciner, et ces décisions influencent la propagation de la maladie. Nous proposons une approche de modélisation flexible qui permet de prendre en compte ces décisions individuelles dans les modèles de simulation épidémiologiques.Dans le Chapitre 1, nous étudions la décision de vaccination face à une maladie inspirée de la rougeole. Nous montrons comment inclure les décisions de vaccination dans un modèle épidémiologique en les calculant comme un point fixe fonctionnel. Nous obtenons des résultats pour un modèle avec taux de mort et de naissance, et perte d'immunité vaccinale. Nos résultats sur longue période de temps mettent en évidence des pics épidémiques récurrents. À titre de comparaison, nous produisons également des résultats pour des individus ayant un comportement adaptatif.Les objectifs du Chapitre~2 sont (i) de montrer que la boucle entre prévalence et comportements individuels ne peut pas être négligée dans les évaluations de politiques de santé publique, et (ii) de présenter un outil pour les inclure dans ces évaluations. Nous développons l'exemple de la vaccination obligatoire contre la rougeole. Notre modèle épidémiologique est le modèle SIR habituellement utilisé pour représenter la rougeole. Nos résultats suggèrent que l'anticipation de la vaccination obligatoire peut conduire à une augmentation transitoire de la prévalence avant l'éradication à long terme de la maladie. Ceci conduirait à d'importants transferts d'utilité entre générations. Ironiquement, dans notre scénario, des individus anti-vaccins sont parmi ceux qui bénéficient le plus de la vaccination obligatoire.Dans le Chapitre~3, nous partons du constat que la comparaison des coûts de vaccination avec le risque d'être infecté par la rougeole peine à expliquer la couverture vaccinale relativement élevée (bien que souvent insuffisante) dans les pays développés. Nous discutons l'hypothèse selon laquelle la vaccination est un comportement coopératif. Nous mettons en œuvre des concepts d'équilibre et de punition habituellement utilisés en théorie des jeux répétés en donnant des arguments pour leur utilisation dans le contexte de la vaccination. Nos résultats indiquent que la menace d'une punition peut expliquer la vaccination lorsqu'elle serait normalement sous-optimale. / We tackle the issue of including individual vaccination decisions in epidemiological models. We draw on the example of Measles vaccination, and we focus on strategic interactions and anticipatory behavior. We contribute to a fuller account of such behaviors by developing a modeling approach intended as a tool for practitioners and theorists.In Chapter 1, we show how the interplay between individual anticipatory vaccination decisions and the otherwise biological dynamics of a disease may lead to the emergence of recurrent patterns. We consider a Measles-like outbreak, rational and far-sighted individuals, vital dynamics, and waning vaccine efficacy. This chapter illustrates the versatility of our approach. For comparison, we provide results for individuals with adaptive behavior.In Chapter 2, we investigate the effect of anticipatory behavior in a scenario where Measles vaccination becomes mandatory. When mandatory vaccination is announced in advance, we show that individuals may alter their vaccination behavior, thus causing an increase in prevalence before Measles is ultimately eradicated. These transition effects lead to non negligible welfare differences between generations. We consider an anti-vaccinationist subpopulation with a higher vaccination cost, and exhibit scenarios where anti-vaccinationists are among those who benefit the most from mandatory vaccination.In Chapter 3, we discuss whether coalitions of vaccinating individuals can account for the relatively high vaccination coverages observed in developed countries. We explain why and how retaliation concepts usually found in repeated games can be used in the context of vaccination, even though individuals vaccinate only once. This allows us to model how vaccinating individuals might retaliate against those who refuse vaccination. We show that retaliation threats can sustain vaccination where it would otherwise be suboptimal for individuals.

The general topic of our thesis is forward looking behavior in strategic situations. Mixing theoretical and experimental analysis, we document how strategic thinking is affected by the specific features of a dynamic interaction. The overarching result is that the information regarding decisions that are close to the current one, receive a qualitatively different consideration, with respect to distant ones. That is, the actual decisions are based on reasoning over a limited number of steps, close to actual decison node. We capture this feature of behavior both in a strategic (limited backward induction) and in a non-strategic (limited farsightedness) set up, and we identify relevant consequences on the outcome of the interaction, which powerfullly explain many observed experimental regularities.<p>In the first essay, we present a general out-of-equilibrium framework for strategic thinking in sequential games. It assumes the agents to take decisions on restricted game trees, according to their (limited) foresight level, following backward induction. Therefore we talk of limited backward induction (LBI). We test for LBI using a variant of the race game. Our design allows to identify restricted game trees and backward reasoning, thus properly disentangling LBI behavior. The results provide strong support in favor of LBI. Most players solve intermediate tasks - i.e. restricted games - without reasoning on the terminal histories. Only a small fraction of subjects play close to equilibrium, and (slow) convergence toward it appears, though only in the base game. An intermediate task keeps the subjects off the equilibrium path longer than in the base game. The results cannot be rationalized using the most popular models of strategic reasoning, let alone equilibrium analysis.<p>In the second essay, a subtle implication of the model is investigated: the sensitivity of the players’ foresight to the accessibility and completeness of the information they have, using a Centipede game. By manipulating the way in which information is provided to subjects, we show that reduced availability of information is sufficient to shift the distribution of take-nodes further from the equilibrium prediction. On the other hand, similar results are obtained in a treatment where reduced availability of information is combined with an attempt to elicit preferences for reciprocity, through the presentation of the centipede as a repeated trust game. Our results could be interpreted as cognitive limitations being more effective than preferences in determining (shifts in) behavior in our experimental centipede. Furthermore our results are at odds with the recent ones in Cox [2012], suggesting caution in generalizing their results. Reducing the availability of information may hamper backward induction or induce myopic behavior, depending on the strategic environment.<p>The third essay consists of an experimental investigation of farsighted versus myopic behavior in network formation. Pairwise stability Jackson and Wolinsky [1996] is the standard stability concept in network formation. It assumes myopic behavior of the agents in the sense that they do not forecast how others might react to their actions. Assuming that agents are perfectly farsighted, related stability concepts have been proposed. We design a simple network formation experiment to test these extreme theories, but find evidence against both of them: the subjects are consistent with an intermediate rule of behavior, which we interpret as a form of limited farsightedness. On aggregate, the selection among multiple pairwise stable networks (and the performance of farsighted stability) crucially depends on the level of farsightedness needed to sustain them, and not on efficiency or cooperative considerations. Individual behavior analysis corroborates this interpretation, and suggests, in general, a low level of farsightedness (around two steps) on the part of the agents. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished