Cette thèse s’intéresse à l’impact conjoint du creusement des inégalités de revenus et des effets de démonstration sur la demande de consommation. Tout particulièrement, ce travail s’attache à définir dans quelles mesures les inégalités de revenus engendrent- elles une demande de luxe et participent-Elles à la dynamique d’innovation. L’analyse s’inscrit dans le cadre des préférences non- homothétiques et traite des aspects sociologiques de l’acte de consommation. L’étude de la littérature macroéconomique sur les inégalités de revenu et la consommation de luxe, constitue le chapitre premier de la thèse. Elle permet de constater que ce champs d’analyse se heurte à l’absence d’une définition communément admise et précise de ce qu’est un bien de luxe. Ce chapitre met en avant l’intérêt d’analyser l’effet du désir de distinction social au sein d’un modèle dans lequel les biens répondant au désir de prestige ont non seulement une fonction sociale, mais aussi une utilité intrinsèque et puissent être le résultat d’une innovation technologique. Le deuxième chapitre étudie la notion de désirs et ses conséquences sur la demande, il propose, notamment, un mécanisme explicatif de l’émergence les désirs et de leur développement dans le temps. Il apporte également une représentation formelle de la croissance des normes de consommation dans un contexte social et montre dans quelle mesure la croissance des désirs participe au changement technologique via les demandes individuels de consommation. Ce chapitre apporte le socle théorique sur lequel est construit un modèle dynamique, proposé dans le troisième chapitre et dans lequel l’incitation à innover provient de la demande de consommation. / This Ph.D. thesis focuses on the joint impact of increasing income inequality and demonstration effects on consumer demand. In particular, it attempts to define to what extent income inequality generates luxury consumption and participates in innovation dy- namics. The analysis is part of non-Homothetic preferences framework and discusses sociological aspects of consumer behaviour. The first chapter reviews the macroeconomic literature on income inequality and luxury consumption. It shows that the analysis of luxury from demand point of view comes up against the absence of a commonly accepted and precise definition of luxury goods. The chapter puts forward the interest to analyze the effect of the desire of social distinction within a model in which goods an- swering the want for prestige have, not only a social function, but also an intrinsic utility and can be the product of a technological innovation. The second chapter examines the notion of wants and its consequences on demand. It establishes the mechanism by which wants appear and develop in time. It brings a formal representation of the growth of consumption standards in a so- cial context and shows to what extent the growth of wants participates in the dynamics of technical change through individual consumption demand. This chapter provides a theoretical framework on which is built a dynamical model, exposed in the third chapter, in which the incentive to innovate comes from the consumer demand. Using agent-Based modeling, this chapter explores the relation between conspicuous consumption and product innovation under various states of income inequality and different social influences.

This master thesis is written as a part of The Media Technology program at Linköping University in collaboration with the streaming music company Spotify. The thesis investigates how a software company in the modern age effectively and organically can stay innovative through times. The thesis maps out strategies, models and methods currently known, analyses Spotify’s innovative efforts over the past year and suggests a framework tailored to the needs of the company.

<div>This thesis consists of three chapters. In the first chapter, I investigate the effects of complexity in various voting systems on individual behavior in small group electoral competitions. Using a laboratory experiment, I observe individual behavior within one of three voting systems -- plurality, instant runoff voting (IRV), and score then automatic runoff (STAR). I then estimate subjects' behavior in three different models of bounded rationality. The estimated models are a model of Level-K thinking (Nagel, 1995), the Cognitive Hierarchy (CH) model (Camerer, et al. 2004), and a Quantal Response Equilibrium (QRE) (McKelvey and Palfrey 1995). I consistently find that more complex voting systems induce lower levels of strategic thinking. This implies that policy makers desiring more sincere voting behavior could potentially achieve this through voting systems with more complex strategy sets. Of the tested behavioral models, Level-K consistently fits observed data the best, implying subjects make decisions that combine of steps of thinking with random, utility maximizing, errors.</div><div><br></div><div>In the second chapter, I investigate the relationship between the mechanisms used to select leaders and both measures of group performance and leaders' ethical behavior. Using a laboratory experiment, we measure group performance in a group minimum effort task with a leader selected using one of three mechanisms: random, a competition task, and voting. After the group task, leaders must complete a task that asks them to behave honestly or dishonestly in questions related to the groups performance. We find that leaders have a large impact on group performance when compared to those groups without leaders. Evidence for which selection mechanism performs best in terms of group performance seems mixed. On measures of honesty, the strongest evidence seems to indicate that honesty is most positively impacted through a voting selection mechanism, which differences in ethical behavior between the random and competition selection treatments are negligible.</div><div><br></div><div><br></div><div>In the third chapter, I provide an investigation into the factors and conditions that drive "free riding" behavior in dynamic innovation contests. Starting from a dynamic innovation contest model from Halac, et al. (2017), I construct a two period dynamic innovation contest game. From there, I provide a theoretical background and derivation of mixed strategies that can be interpreted as an agent's degree to which they engage in free riding behavior, namely through allowing their opponent to exert effort in order to uncover information about an uncertain state of the world. I show certain conditions must be fulfilled in order to induce free riding in equilibrium, and also analytically show the impact of changing contest prize structures on the degree of free riding. I end this paper with an experimental design to test these various theoretical conclusions in a laboratory setting while also considering the behavioral observations recorded in studies investigating similar contest models and provide a plan to analyze the data collected by this laboratory experiment.</div><div><br></div><div>All data collected for this study consists of individual human subject data collected from laboratory experiments. Project procedures have been conducted in accordance with Purdue's internal review board approval and known consent from all participants was obtained.</div>