[pt] Esse trabalho investiga o papel da descoberta de produto na demanda por jogos eletrônicos. Nós mostramos que o padrão de vendas para jogos eletrônicos é bastante variado, com alguns jogos tendo suas vendas imediatamente depois de seus lançamentos, e outros com caldas de venda maiores. Para entender essas diferenças nós propomos um modelo de demanda em que consumidores são periodicamente informados sobre a existência de um jogo e exploramos o padrão de vendas que isso implica. Em seguida aplicamos o modelo aos dados usando dados de preços e vendas da plataforma digital Steam e dados e busca online do google trends. Nossos resultados sugerem que vendas três meses depois do lançamento são em média metade do que seria caso consumidores tivessem informação completa. / [en] This paper investigates the role of product discovery in the demand for video games. We show that the lifetime sales patterns for video games vary widely, with some games selling most of their units in the first months after launch and others having longer tails. To understand these differences we propose a demand model in which consumers are periodically informed about the existence of a game and explore the lifetime sales patterns that this implies. We then take it to the data using price and sales figures from the Steam digital platform and web search figures from google trends. Our results imply that sales three months after launch are on average half of what they should be were consumers fully informed.

Diplomová práce se zabývá základní slovní zásobou standardní češtiny ve vztahu mluvčím češtiny jako zd d ného jazyka. Jedná se o druhou generaci mluvčích češtiny, kte í vyr stali v N mecku, konkrétn v ezn a okolí. Cílem práce je identifikovat oblasti základní slovní zásob češtiny, které si uvedení mluvčí neosvojili p i ne ízené akvizici Teoretická část práce v první ad vysv tluje pojmy zd d ný jazyk, mluvčí migračním pozadím, nedokonalé osvojení jazyka a základní slovní zásoba s ohledem na né mluvčí. Dále na základ zahraniční odborné literatury popisuje problematiku vymezení základní slovní zásoby a tyto poznatky aplikuje na češtinu. T žišt m teoretické části práce je vymezení aktivní a pasivní slovní zásoby češtiny a její rozsah a základní slovní zásobu češtiny je nahlíženo jak z frekvenčního, tak z komunikačn pragmatického pohledu. Pro účel tohoto výzkum k výb ru základní slovní zásoby následn zvolen frekvenční p ístup s využitím Českého národního korpusu. Empirická část práce popisuje experimentální výzkum, ve kterém byla zkoumána aktivní i pasivní slovní zásoba a schopnost mluvčích češtiny jako zd d ného jazyka používat synonyma. Z výzkumu vychází, že tito mluvčí mají osvojené p ibližn čty i p tiny základní slovní zásoby standardní češtiny. Mezi nejobtížn jší slova pro tyto mluvčí pat í tzv. "faux amis"...

La tesi studia l'interazione tra potere di mercato, disuguaglianza e benessere in un modello dinamico di equilibrio generale. A tal fine è necessario abbandonare due capisaldi della teoria Neoclassica: l'agente rappresentativo e la competizione perfetta. L'obiettivo del primo capitolo è capire come il potere di mercato influenza la distribuzine di ricchezza e reddito tra le famiglie. I risultati suggeriscono che una semplice estenzione del modello di Aiyagari, in particolare competizione oligopolistica con dinamica delle imprese endogena, riesce a replicare le distribuzioni osservate nei dati USA. Inoltre, un incremento del grado di concentrazione nel mercato dovuto a un aumento dei costi di entrata, implica una più bassa Labor Share e una più alta Profit Share. A loro volta queste dinamiche causano un incremento della disuguaglianza. Anche questi trend sono in linea con ciò che si può osservare dai dati USA. Il secondo capitolo estende il modello sviluppato nel primo per studiare il ruolo della tassazione dei dividendi nel redistribuire risorse. L'analisi considera due regimi alternativi. Una riduzione dell'aliquota sui dividendi, dallo Status Quo statunitense, comporta una perdita di benessere per la società. Una più bassa tassazione riduce i trasferimenti monetari alle famiglie, implicando alti costi per quelle più povere. Inoltre, una riduzione dei trasferimenti causa un incremento dei risparmi. Per poter risparmiare di più gli agenti meno abbienti devono sacrificare consumo. Dato che la ricchezza è molto concentrata, la maggior parte della popolazione soffre una perdita di benessere. / This work studies the interactions between market power, inequality, and welfare in a dynamic, general equilibrium framework. Doing so requires departing from two building blocks of the neoclassical general equilibrium model: the representative agent paradigm and perfect competition. The aim of the first chapter is to understand whether market power affects the distributions of wealth and income among households. Results suggest that a relatively simple extension of the Aiyagari model, namely oligopolistic competition with endogenous firms’ dynamics, is successful at reproducing the wealth and income distributions observed in the U.S. Additionally, an increase in concentration in the markets for final goods, due to an increase in entry costs, leads to a lower labor share and a higher profit share of income. These dynamics, in turn, imply higher income inequality. Importantly, these trends are broadly in line with those observed in the U.S. in the last thirty years. The second chapter extends the framework developed in chapter one to study the role of the dividend income tax as a redistributive tool. The analysis considers alternative redistribution regimes. The main finding is that a reduction of the dividend income tax rate, from the US Status Quo, is associated with a social welfare loss. A lower dividend income tax rate implies lower transfers to households. From a welfare point of view, this is particularly costly for poor households. Furthermore, a reduction in transfers forces households to save more for precautionary reasons. To do so, wealth poor households must sacrifice consumption. Given the high concentration of wealth, this implies that the majority of the population suffers a welfare loss.

L'objet de cette thèse est l'étude des aspects algorithmiques du vote par approbation. Il s'agit principalement d'une étude théorique des enjeux computationnels soulevés par le vote par approbation dans des contextes de décisions variés. Cependant, j'étudie aussi des questions plus proches de la théorie classique du choix social et je conduis de brèves études expérimentales.Dans un premier temps, l'étude se porte sur une famille générale de règles de vote pour les élections de comités et les référendums multiples à l'aide du vote par approbation. Dans un second temps, je porte mon attention sur un contexte plus général, le vote par approbation sur domaines combinatoires en se basant sur des préférences conditionnelles. Finalement, je me place dans le cadre du vote avec préférences incomplètes pour étudier les problèmes de vainqueurs possibles et nécessaires dans le vote par approbation. / The subject of this thesis is the study of computational aspects of approval voting. Most of the works are theoretical results about computational issues raised by approval voting, in many different settings. However, I also study some questions that are more related to classical choice theory, and some problems are investigated through experimental analysis.Firstly, I study a general family of rules for approval voting in the context of committee elections and multiple referenda. Secondly, I focus on a more general setting, approval voting in combinatorial domains, based on conditional preferences. Finally, I consider approval voting in the context of incomplete preferences, to study the possible and necessary winner problems.

Cette thèse s’intéresse à différents problèmes de contrôle et d’optimisation dont il n’existe à ce jour que des solutions approchées. D’une part nous nous intéressons à des techniques visant à réduire ou supprimer les approximations pour obtenir des solutions plus précises voire exactes. D’autre part nous développons de nouvelles méthodes d’approximation pour traiter plus rapidement des problèmes à plus grande échelle. Nous étudions des méthodes numériques de simulation d’équation différentielle stochastique et d’amélioration de calculs d’espérance. Nous mettons en œuvre des techniques de type quantification pour la construction de variables de contrôle ainsi que la méthode de gradient stochastique pour la résolution de problèmes de contrôle stochastique. Nous nous intéressons aussi aux méthodes de clustering liées à la quantification, ainsi qu’à la compression d’information par réseaux neuronaux. Les problèmes étudiés sont issus non seulement de motivations financières, comme le contrôle stochastique pour la couverture d’option en marché incomplet mais aussi du traitement des grandes bases de données de médias communément appelé Big data dans le chapitre 5. Théoriquement, nous proposons différentes majorations de la convergence des méthodes numériques d’une part pour la recherche d’une stratégie optimale de couverture en marché incomplet dans le chapitre 3, d’autre part pour l’extension la technique de Beskos-Roberts de simulation d’équation différentielle dans le chapitre 4. Nous présentons une utilisation originale de la décomposition de Karhunen-Loève pour une réduction de variance de l’estimateur d’espérance dans le chapitre 2. / This thesis proposes different problems of stochastic control and optimization that can be solved only thanks approximation. On one hand, we develop methodology aiming to reduce or suppress approximations to obtain more accurate solutions or something exact ones. On another hand we develop new approximation methodology in order to solve quicker larger scale problems. We study numerical methodology to simulated differential equations and enhancement of computation of expectations. We develop quantization methodology to build control variate and gradient stochastic methods to solve stochastic control problems. We are also interested in clustering methods linked to quantization, and principal composant analysis or compression of data thanks neural networks. We study problems motivated by mathematical finance, like stochastic control for the hedging of derivatives in incomplete market but also to manage huge databases of media commonly known as big Data in chapter 5. Theoretically we propose some upper bound for convergence of the numerical method used. This is the case of optimal hedging in incomplete market in chapter 3 but also an extension of Beskos-Roberts methods of exact simulation of stochastic differential equations in chapter 4. We present an original application of karhunen-Loève decomposition for a control variate of computation of expectation in chapter 2.

The diploma thesis deals with the process of prison privatization in the United Kingdom particularly in England and Wales especially in the form of PFI deals, in which the private sector not only manages prison facility but also designs and constructs the buildings. Due to transfer of this kind of service we can look at the relationship between state and private provider trough the lenses of Principal-agent theory. This theory, in its purest form, is constituted of one principal and one agent to whom the performance of the service is transferred, part of the risks associated with it and also a certain decision-making power are transferred as well. According to the theory, the basic precondition for the relationship between the principal and the agent is a discrepancy in the goals of the actors and the agent's effort to act opportunistically at the expense of the performance of the service for the principal. In this sense, the thesis examines the decision from 2018 not to launch new PFI or its successor PF2 projects. In this scenario, England and Wales are the principal and the prison operators are the agents. The hypothesis of the thesis is that this decision not to launch new PFI projects is related to problematic aspects of the relationship between the principal and the agent and that the control...

This thesis is focused on consequences which are associated with the loss of a breadwinner in the family. The aim is to identify and describe the impacts on families and compare these consequences in the cases of divorce and death. At first this paperwork brings information about family and its peculiarities. Other chapters are devoted to single-parent families as a result of a divorce, and death. In these chapters, we focused on the impacts of these two events. There are described primarily impacts on economic, social, educational and psychological aspects of the family. Information in this chapter are supported by excerpts from interviews that were conducted with several women, who have lost husbands, and thus became the breadwinners. The next chapter is devoted to the role of the state in this issue. It describes how family policy is designed and how the state directly compensates for the loss of a breadwinner in these two cases. The end of this chapter provides a brief description of family policy, focusing on the loss of a breadwinner in several other European Union states. The last chapter provides an analysis of the interviews, and there we can see what are the impacts on the family, which single mothers perceive. And what is the difference in impacts at these two events.

No description available.

. / Corporate acquisitions are classified as part of “the market for corporate control” in which management teams are facing constant competition from other management teams. If the team that currently controls a company is not maximizing the value of the company’s assets, then an acquisition will likely occur and increase the value of the company by replacing its poor managers with good managers. This dissertation focus on two issues on mergers, the first compares the strategy between mergers and joint ventures. The second investigate how much liquidity should the acquirer preserve and what is the equilibrium price of the acquired firm in considering the merger strategy. Drawing upon the incomplete contract theory, I examine the criterion of the strategic choice between joint ventures (JVs) and mergers when two firms contemplate vertical integration. The model reaches the following conclusions: (1) some ownership provision to the acquired company after the mergers may prove to be more lucrative to the acquirer than 100% takeover; (2) given the same equity share arrangement for JVs and mergers I conclude that these two firms should choose to merge or be merged rather than JVs; (3) I derive the optimal equity share arrangement in both JVs and mergers when ownership provision is considered as a strategic means. In addition, I also compare the welfare and effort of both companies in JVs and mergers under symmetric cost structures, and find that mergers would provide greater social efficiency and welfare than 50-50 JVs when the acquirer’s equity share is between 30% and 65%. Firms are concerned that they may in the future be deprived of the funds that would enable them to take advantage of exciting growth prospects, strengthen existing investments or simply stay alive. I specifically examine a firm’s liquidity need in order to grasp any future opportunity of mergers and acquisitions. However, a firm’s manager (borrower) can shed his interim wrongdoings (misbehavior) under the pretext of further financial need for mergers and acquisitions because he knows that he can easily raise sufficient cash from lenders to cover any adverse shock. My study derives the conditions that when this soft-budget-constraint (SBC) problem will occur. It happens when the interim income is small. Moreover, I analyze how the purchase price of acquisition is affected by this soft-budget-constraint syndrome. If there is SBC problem, the acquisition price will be raised by the investors when the interim income is small. Besides, a firm with severe moral hazard problem will be merely able to offer a smaller purchase price for the acquisition. On the contrast, a firm with a stronger balance sheet will be able to secure a greater credit line and offer a more attractive price for the acquisition. The empirical study of U.S. firms during 1988 to 2006 supports my conclusions.

No description available.