Cette thèse se situe à l’interface entre la théorie quantique et les expériences, en mettant l’accent sur les protocoles pratiques qui peuvent être mises en place en utilisant la technologie présente. Notre objectif est de contribuer à la construction d’un cadre général pour la conception et la mise en oeuvre de schémas de chiffrement quantiques qui permettront d’améliorer la sécurité des futurs réseaux de télécommunication. En outre, cette thèse veut avancer la recherche pertinente sur la physique quantique et l’informatique, en améliorant notre compréhension du phénomène d’intrication. Les corrélations des états intriqués ne peuvent pas être reproduites par des moyens classiques, ce qui permet d’effectuer des tâches (par exemple la téléportation et le codage super-dense) qui sont autrement impossibles. Il est donc d’une importance majeure d’être capables de vérifier si un état quantique est intriqué. Dans cette thèse, nous montrons comment vérifier efficacement si une source physique peut créer des états intriqués multipartites et les partager avec de nombreuses parties, dont certains sont malhonnêtes et collaborent avec la source. Ce protocole pourrait s’avérer essentiel pour tout type de calcul quantique entre les parties méfiantes et pourrait aussi faciliter la délégation sécurisée des tâches de calcul aux serveurs quantiques puissants qui ne sont pas fiables. Finalement, nous étudions le lien entre la théorie des jeux et la non-localité quantique, dans le cadre de jeux bayésiens. Nous examinons comment l’intrication partagé aide les joueurs gagner un jeu avec une probabilité plus élevée que les ressources classiques pourraient atteindre. / This thesis stands at the interface between quantum theory and experiments, focusing on practical protocols that can be implemented using present-day technology. Our goal is to build a general framework for the design and implementation of quantum cryptographic schemes that will improve the safety of future telecommunication networks. In addition, this thesis aims to advance research on quantum physics and computer science, by improving our understanding of entanglement. The correlations of entangled states can not be reproduced by conventional means, allowing to perform tasks (eg teleportation and superdense coding) that are otherwise impossible. It is therefore of major importance to be able to check whether a quantum state is entangled. In this thesis, we show how to efficiently check whether a physical source can create multi-party entangled states and share them with many parties, some of which are dishonest and work with the source. This protocol could prove essential for quantum computation between suspicious parties and could also facilitate the secure delegation of tasks to powerful untrusted quantum servers. Finally, we study the link between game theory and quantum non-locality, in the context of Bayesian games. We examine how the shared entanglement helps players win a game with a higher probability than the conventional resources could achieve.

Game theory was used to analyze compensation systems based on individual and group incentives. Payoff formulas were developed for these incentives assuming different preferences for individual and social outcomes. Two levels of contributions were considered: (1) Defection. The minimum acceptable level of contributions, and (2) Cooperation. A level of discretionary contributions above the minimum. The discretionary contributions associated with cooperation were represented as a cost to the individual. A classification scheme for uniform n-person games was developed using the approach of Rappaport and Guyer (1966) for 2 x 2 games. This classification scheme defines the natural outcome (cooperation or defection) for each game. The analysis considered the Individual motive, based on maximizing self-interest, and five social motives (Collective, Competitive, Altruism, Equity and Aggression). These motives reflect preferences for outcomes based on payoffs to self and others. The results indicate the natural outcome and game category for different values of the individual and group incentive factors. Satisficing theory was also used to analyze the natural outcome for the Individual motive. Evolutionary game theory was used to develop two simulation models for social motives. The models interpret social motives as (1) genuine preferences for specific social outcomes, or (2) indirect strategies for maximizing individual payoffs. These models explore the interaction of social motives and the resulting impact on the level of cooperation. The results were used to develop effectiveness criteria for selecting inducement systems which should promote cooperation. Additionally, cost curves were used to determine the least cost inducement system. Based on these results, inducement systems using absolute incentives are recommended over systems using competitive incentives. Competitive incentives should only be considered when there is limited need for coordination between individuals and where aggressive and/or competitive behavior is acceptable. The study has theoretical as well as practical implications. Game theory provides a method for expanding expectancy theory to include expectations about the actions of others and provides a framework for integrating expectancy theory and other theories based on social motives (e.g. equity theory). The use of dynamic models from evolutionary game theory breaks new ground in the theory of motivation.

No description available.

京都大学 / 新制・課程博士 / 博士(経済学) / 甲第24378号 / 経博第665号 / 新制||経||303(附属図書館) / 京都大学大学院経済学研究科経済学専攻 / (主査)教授 関口 格, 教授 原 千秋, 准教授 陳 珈惠 / 学位規則第4条第1項該当 / Doctor of Economics / Kyoto University / DFAM

No description available.

Thesis advisor: Mehmet Ekmekci / This dissertation consists of three essays on media, political and learning. More specifically, I investigate the effects of biased media and learning from that biased media on political institutions. In the first essay, titled “Optimal Dynamic Information Supply and Competition”, I provide a model of an information market where the viewers acquire signals each period at an attention cost, solving an optimal stopping problem à la Wald (1947), and the objective of the potentially biased information providers is to maximize the number of viewers who acquire signals from them across periods. I find that, in a monopoly market, the information provider sends unbiased signals that perfectly reveal the state of the world when there is a single period but provides biased signals when there are multiple periods. This is because biased signals elongate the learning process of some viewers, potentially increasing the information provider payoff. I also find that incentives due to competition, modeled as another information provider that is potentially biased in the opposite direction, overtake the intertemporal incentives and the full information equilibrium is recovered, even though it is wasteful in terms of social welfare. Hence, the paper provides a model with rational information providers and viewers that leads to biased signals in equilibrium. In the second essay, titled “Voter Behavior and Information Aggregation in Elections with Supermajority”, I provide a model of elections where there are three possible outcomes, but the voters can directly vote for one of the two options. Theoutcome of the election corresponds to the options if the vote share for one of them is higher than a supermajority threshold. If neither of the options achieves that, then the result is the third outcome that the voters cannot explicitly vote for, which I interpret as compromise. I investigate various properties of elections in this setting. I find that, in line with the popular argument, supermajority rules foster compromise outcomes. But, on the other hand, elections with supermajority rules fail to aggregate information. In the third essay, titled “Protests, Strategic Information Provision and Political Communication”, I consider a model of protests where the protesters learn about the state of the world via a biased information provider whose objective is to either instigate or dissuade the protest. A successful protest removes the incumbent from office, where the success threshold is determined by the incumbent who is biased. My main aim is to uncover whether the incumbent can learn the true state of the world from the protest turnout, even though the information of the citizens is provided by biased media. I pin down the optimal success threshold and signal noise choices by the incumbent and the information provider, respectively. I find that if the information provider is trying to instigate the protest, then political communication is always possible, regardless of the level of the bias of the incumbent. If the information provider is trying to dissuade the protest, then political communication is possible if and only if the incumbent bias is relatively small. / Thesis (PhD) — Boston College, 2023. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

No description available.

No description available.

Chapter 1 novelly examines the nature of the interaction between private donors and not-for-profit organisations (NPOs) when NPOs can invest endowment funds in a two-asset risky portfolio and donors can contribute to both the endowment fund and the annual campaign. I study a three-stage non-cooperative game with two types of economic agents: a cohort of heterogeneous donors and one representative NPO. In equilibrium, donors always contribute to the endowment fund; however, they may not contribute to the annual campaign. The proportion of the NPO's endowment fund invested in the risky asset is a discontinuous function of the endowment; donors contribute less to an aggressive NPO and more to a cautious one. When the NPO can solicit donors to contribute only once, this increases the expected level of the contribution in equilibrium, but this may not generate higher expected utility for donors. Chapter 2 presents a dynamic model of charitable giving. At each period, donors contribute to an NPO's endowment; the NPO provides a charitable good and invests in the  financial market. Investments are made in a risky asset and a risk-free asset. I introduce two types of shocks to account for uncertainty: donors' income shock and  financial market fluctuations. I show that the optimal share of disposable endowment invested in risky asset is constant. Donors' strategy, whether to contribute or free-ride on the NPO's investments, depends on donors' shadow prices. Donors contribute when NPO's endowment is relatively low. Large contribution levels encourage the NPO to participate in the capital market at the expense of providing charitable good. I show that the NPO prefers an environment with a lower rate of return on risk-free assets. NPO's risk exposure to the  financial market affects both NPO's and donors' decisions. However, risk exposures on donors' side do not impact parties' decisions. Regulation analysis suggests that portfolio ceiling and provision floor are achievable. Chapter 3 links two data sources: the National Center for Charitable Statistics (NCCS) data over the period of 1987-2014 and the U.S. presidential elections data. I develop a dynamic model to examine how the national-level political incumbent shapes the NPOs' risky investment portfolio selection, adjusting for a set of NPOs' intrinsic characteristics and real interest rate. I  find that right-leaning Republicans act as a rein on NPOs' risky investments, i.e., a Republican administration is associated with a reduction in NPOs' holdings of corporation stocks and a 16.28% reduction in equity share relative to a Democratic administration. It is attributed to the impact of the Republican administration by more facilitating NPOs' accessibility to borrowing than having a Democratic president. I argue that NPOs behave as backward-looking investors or are reluctant to change their portfolio due to the significant portfolio adjustment cost, using past performance as an indicator to make their current risky investment decisions. Heckman two-step estimation indicates that NPOs' investment is an endogenous sample selection instead of a random choice. I show that NPOs have a less extensive equity share with more severe agency costs; foundation size plays a different role when NPOs decide whether to invest in risky assets compared with investing NPOs. Moreover, for investing NPOs, the equity share is expected to decrease by 12.0% if there is a 1% increase in the real interest rate; NPOs are more inclined to invest in risky assets when the real interest rate increases, in the sense of riding with the rational bubble.

To deter is central for strategic thinking. Some of the more astute observations regarding the dynamics of deterrence were made during the Cold War by game theorists. This set the stage for how deterrence has come to be studied. A strong methodological element like the research on deterrence’s reliance on game theory requires examination in order to understand what sort of knowledge it actually yields. What sort of knowledge does one acquire when deterrence is viewed through game theoretic models? How do they inform us about the phenomenon of deterrence? To understand the nature of a phenomenon through models requires idealization, which in turn presupposes assumptions. This licentiate thesis investigates the type of knowledge we attain when approaching deterrence from a game theoretic perspective. The two articles presented address two separate but related issues. The first article reviews a debate regarding which deterrence model best capture the phenomena of deterrence, i.e. how models can be compared to one and other. The article presents a framework for comparing models and then appraises how these different deterrence models inform us about deterrence. The second article uses one of the more central deterrence models in order to evaluate how and to what extent the naval operation Atalanta managed to deter the Somali piracy. / <p>QC 20190201</p>