Fictitious play is a classical learning process for games, and games with strategic complementarities are an important class including many economic applications. Knowledge about convergence properties of fictitious play in this class of games is scarce, however. Beyond games with a unique equilibrium, global convergence has only been claimed for games with diminishing returns [V. Krishna, Learning in games with strategic complementarities, HBS Working Paper 92-073, Harvard University, 1992]. This result remained unpublished, and it relies on a specific tie-breaking rule. Here we prove an extension of it by showing that the ordinal version of strategic complementarities suffices. The proof does not rely on tie-breaking rules and provides some intuition for the result.

This thesis examines the relationship between institutional context and firm performance, from both a theoretical and empirical perspective. The aim is to engage with the debate seeking to explain the observed diversity in the forms of economic organisation prevailing in socio-economic systems. The focus of the empirical work is on investigating the effects of the structure and behaviour of banking institutions on firm performance, in the Italian context. The analysis is comparative in the sense that confronts cooperative and capitalist business structures. The analytical framework is institutionalist in emphasising the institutionally embedded nature of economic performance, and the historical and cultural dimensions of economic behaviour. The institutional complementarity approach is used to investigate the hypothesis that the relative performance of different firm structures is context dependent. The main conclusions are that the economic performance of cooperative firms is strongly conditioned in a sense of institutional complementarity by the degree of development and competition characterising the financial domain. Rejected are the pessimistic predictions of conventional accounts that democratic firms are unequivocally unviable. Instead, there are relations of context dependency, of institutional complementarity that influence the viability of firm types. The overall conclusion is that the dynamics governing the evolution of socio-economic systems are much more complex than mainstream economics suggests; productive organisations may assume a multiplicity of forms. The theoretical claims of a universalistic history in which all production systems must follow the same line of development must be abandoned. This brings about major policy implications at the regional, national and international levels.

This dissertation focuses on understanding and modeling how contracts function in practice. The existing principal-agent literature usually involves two players: a principal (investors) provides capital to an agent (managers or entrepreneurs) on a project subject to asymmetric information. However, many real financing arrangements between firms and investors are intermediated by another agent - a bank, a venture capitalist, or a fund family, etc. In these three-tier settings, there are two contracts to deal with two conflicts of interest - a framework that simply hasn't been studied thoroughly in the principal-agent literature. The first chapter is co-authored with my Ph.D. advisors Prof. Andrea M. Buffa and Prof. Lucy White. In this chapter, we consider a general economic setting in which a principal has all the bargaining power, and she has to hire two agents exerting complementary efforts on her project. The principal chooses from two contracting schemes - direct contracting and delegated contracting - whether to contract directly with both agents or instead to contract with one agent alone and delegate this agent to contract with the other agent. We find that delegated contracting can be optimal when contracts are private. With direct contracting, each agent fears that the principal will opportunistically reduce the other agents' bonus, muting incentives to exert effort. With delegated contracting, one agent observes the contract of the agent he hires, alleviating effort concerns, but allowing rent extraction. In delegating, the principal trades off the losses of control and rent extraction by the hiring agent against the gains from improved observability and effort. We find that it is optimal for the principal to delegate when the hiring agent is sufficiently skilled or the effort complementarity is sufficiently strong. The second chapter considers an entrepreneurial finance setting in which an entrepreneur needs two things - expert advice and capital - in addition to her own idea and effort. The entrepreneur has all the bargaining power, and she chooses to finance her project from two sources: angels and venture capitalists. Venture capitalists are different from angels in two aspects. First, angels are individuals investing their own capital, while venture capitalists are intermediaries investing on behalf of limited partners (LPs). Second, venture capitalists provide expert advice while angels don't. With angel financing, the entrepreneur obtains expert advice from a consultant who is independent of the angels. With venture capital financing, the entrepreneur obtains expert advice bundled together with capital from a venture capitalist only. I show that when contracts are private, raising capital directly from angels is more expensive because the entrepreneur has the incentive to cut down on expert advice to save money. Angels optimally set a higher cost of capital to be compensated for the lack of verifiability. On the other hand, LPs are able to infer the amount of expert advice through the venture capitalist's shares in the venture. I show that venture capital financing is optimal for the entrepreneur in competitive labor and capital markets. Moreover, convertibles arise endogenously as the optimal security held by the venture capitalist. Convertible securities have features of both debt and equity, allowing the entrepreneur to provide enough incentives to the venture capitalist while minimizing the cost of capital from the LPs. The third chapter further analyzes the entrepreneur's optimal financing problem in which venture capital is scarce relative to angel capital. Compared with competitive venture capital, the venture capitalist's compensation stays the same while the LPs demand a higher return. The entrepreneur and the venture capitalist share the extra cost of financing, and their expected payoffs and the project's profitability decrease in the scarcity level of venture capital. With venture capital financing, the entrepreneur trades off the loss due to the scarcity of venture capital against the gains from the improved transparency in contracting. I find that angel financing is optimal when venture capital is sufficiently scarce. Compared with angel financing, the investors as LPs demand a higher return than angels only when venture capital is scarcer than what it makes angel financing optimal.

The adoption of open innovation models has been widely recognized as an effective strategy to be successful in knowledge creation. This holds true since a joint adoption of internal and external technology sources may bring complementarities in terms of a given performance measure. The assessment of these complementarities and the examination of the conditions favoring them are the main objective of this research. First, the thesis examines the process of knowledge provision in the case of alternative alliances (e.g., collaboration and R&D outsourcing), and assesses its effects on the formation of inter-organizational complementarities in R&D. Second, the thesis analyzes how firms organize alternative search strategies that differ from each other in their technological and organizational profiles. The thesis presents a novel taxonomy that proposes three generic models by which firms organize their technological search activities: ambidextrous, specialized and diversified models. From an empirical perspective, the thesis assesses the performance consequences when applying these models, and compares their capacity to produce complementarities in innovative performance. Third, the thesis studies the implementation of inter-organizational ambidexterity in R&D as a method that allows firms to balance tensions in the integration of exploratory and exploitative R&D tasks. Given the potential effects of this balance strategy on the way a firm innovates, the thesis further investigates the main consequences associated with the adoption of inter-organizational ambidexterity in R&D. / Los modelos de innovación abierta han sido ampliamente reconocidos como una estrategia efectiva para favorecer el proceso de creación de conocimiento en las empresas. Este reconocimiento se debe al hecho de que estos modelos facilitan la producción de complementariedades, medidas en términos de algún indicador sobre el rendimiento innovador de las empresas. Dado el carácter estratégico de estas complementariedades, su evaluación y el examen de las condiciones que favorecen su producción constituyen el objetivo principal de esta tesis. En primer lugar, la tesis analiza el proceso de provisión de conocimientos derivado de diferentes tipos de alianzas (i.e., colaboración en I+D, la subcontratación de I + D), evaluando su impacto en la formación de complementariedades ínter-organizativas en I+D. En segundo lugar, la tesis analiza la organización de las estrategias dedicadas a la búsqueda de conocimiento tecnológico usadas por las empresas. Para ello, se considera que dichas estrategias difieren entre si en cuanto a sus perfiles tecnológicos y organizativos. La tesis presenta una nueva taxonomía que propone tres modelos genéricos mediante los 2 cuales las empresas pueden organizan sus actividades de búsqueda tecnológica: el modelo ambidiestro, el modelo especializado y el modelo diversificado. Desde el punto de vista empírico, la tesis analiza las consecuencias sobre la capacidad de innovación de las empresas asociados a la implementación de estos modelos. Adicionalmente, se comparan estos modelos en cuanto a su capacidad de producir complementariedades durante el proceso de innovación de las empresas. En tercer lugar, la tesis estudia la aplicación de la ambidestreza ínter-organizativa en I + D como método de organización de las actividades de exploración y explotación de las empresas. En particular, se analiza la capacidad de este método a la hora de equilibrar las tensiones producidas en la integración de actividades de exploración y explotación en I + D. Teniendo en cuenta los efectos potenciales de estos modelos sobre la innovación en las empresas, la tesis evalúa las principales consecuencias asociadas con su adopción.

Affärsmodellinnovation innebär att en affärsmodell uppdateras och utvecklas för att vara relevant och samspelt med konkurrensen. Det finns flertal forskare som listar olika koncept som organisationer behöver ha med i sina ffärsmodellinnovation för att den ska bli framgångsrik. Men hur blir det när ett bolag försöker sig på affärsmodellinnovation och skapar ett digitalt verktyg för samverkan i en digital omogen bransch som byggbranschen?  Syftet med denna studie är därmed att utforska utmaningar kring affärsmodellsinnovation som fokuserar på utveckling av digitala verktyg för byggbranschen och metoden som används är litteraturstudie samt semistrukturerade intervjuer. Studien resulterar i slutsatsen att det inte räcker med koncepten som forskarna har kommit fram till vad gäller affärsmodellinnovation utan att ett bolag som ska skapar ett digitala verktyg behöver även skapa sig en insikt om hela affärsmodellinnovationensekosystem för att nå fram till sina kunder och partners i en digitalt omogen bransch.

In step with the development of digitalization, information technology has created an opportunity for retail organizations to offer new transaction mechanisms to their customers that can be used to their advantage and benefit value creation. Hence, many retail organizations today work to differentiate themselves by establishing omnichannel practices in which the company’s digital and physical channels are integrated to create a seamless and convenient customer experience. The aim of this study is to produce new knowledge regarding the value generated by omnichannel practices, and is based on a qualitative research method in which a multi-case exploration of six different companies has been carried out. The empirical data consist of nine semi-structured interviews with the organizations involved as well as on observations of the organizations’ omnichannel practices. Based on the results of the study, it is shown that omnichannel providers manage to create value by activating all business model themes, i.e. efficiency, novelty, lock-in and complementarities, in different ways and to varying degrees. It is also noted that various retail organizations have different ease of activating the four different value-creating sources and that this value creation is dependent on the retail organization's main activities and target group.

Cette thèse contribue au débat sur les politiques de ciblage d’inflation et de transparence des banques centrales en présentant notamment trois essais théoriques et empiriques sur le sujet. Dans le premier essai, nous étudions théoriquement les conditions sous lesquelles il serait optimal pour une banque centrale d’adopter explicitement un régime de ciblage d’inflation. Nous proposons un nouveau cadre théorique qui combine les deux principales raisons avancées dans la littérature pour expliquer les effets réels à court terme de la politique monétaire et qui sont d’une part, la présence d’informations hétérogènes entre les agents économiques (Phelps, 1970 ; Lucas, 1972), et d’autre part, la rigidité des salaires ou des prix (Taylor, 1980 ; Calvo, 1983). Nous analysons ensuite notre problématique dans ce nouveau cadre en considérant l’interaction entre le degré de rigidité des prix, et le degré de complémentarités stratégiques dans la fixation de prix des firmes. Nos résultats montrent que l’adoption d’un régime de ciblage d’inflation dépend fortement de l’importance relative des paramètres du modèle. En particulier, nous montrons que le ciblage d’inflation devrait être toujours adopté lorsque les complémentarités stratégiques sont faibles, alors que dans le cas contraire, il est optimal uniquement lorsque les prix sont assez rigides et que la banque centrale détient des informations suffisamment précises sur les fondamentaux de l’économie. Dans le second essai, nous utilisons la macroéconomie expérimentale afin d’évaluer dans quelle mesure l’annonce de la cible d’inflation est pertinente dans un cadre de ciblage de l’inflation. Nos résultats montrent que lorsque la banque centrale ne se soucie que de la stabilisation de l’inflation, l’annonce de la cible d’inflation n’apporte pas de gain supplémentaire en termes de performances macro-économiques, par rapport à une politique monétaire active (type règle de Taylor). Cependant, si la banque centrale intègre également la stabilisation de l’activité économique dans ses objectifs, la communication de la cible contribue à réduire la volatilité de l’inflation, du taux d’intérêt, et de l’écart de production, bien que leurs niveaux moyens ne soient pas affectés. Ce résultat fournit ainsi une justification pour l’adoption d’un régime de ciblage flexible d’inflation par la majorité des pays ciblant l’inflation. Enfin dans le troisième essai, nous appliquons une analyse transversale ainsi que la technique des variables instrumentales, afin d’analyser les effets de la transparence des banques centrales sur les résultats macroéconomiques dans les pays émergents. Nous construisons un nouvel indice de transparence qui combine certains aspects de l’indice de transparence globale d’Eijffinger et Geraats (2006), avec ceux de l’indice de transparence sur le comité de politique monétaire de Hayo et Mazhar (2011). Nous analysons ensuite le rôle individuel de chaque composante du nouvel indice en termes de réduction du niveau de l’inflation et de sa volatilité, ainsi que de la volatilité du produit. Contrairement à la littérature antérieure, nous trouvons que le nouvel indice de transparence ainsi que ses aspects économique, politique, procédurale et de transparence sur la politique monétaire impactent négativement le niveau moyen de l’inflation, mais pas sa volatilité dans ces pays. L’unique composante du nouvel indice qui permet de réduire à la fois la volatilité de l’inflation et celle de la production est la transparence opérationnelle. Ces résultats s’avèrent robustes aux différentes spécifications de modèles économétriques utilisés dans cet essai. / This dissertation contributes to the debate on inflation targeting and central bantransparency by presenting three theoretical and empirical essays on the topic. In the first essay, we theoretically investigate the conditions under which it would be optimal for a central bank to explicitly adopt an inflation targeting regime. We propose a new theoretical framework that combines the two main frictions put forward in the literature to explain the real short run effects of monetary policy that is, heterogeneous information among agents (Phelps, 1970; Lucas, 1972), and wage or price rigidities (Taylor, 1980; Calvo, 1983). We then analyze our issue in this new framework by considering the interaction between the degree of price stickiness, and the degree of strategic complementarities in firms’ price setting. Our results show that adopting an inflation targeting regime crucially depends on the relative importance of the model’s parameters. In particular, we show that inflation targeting should always be adopted when strategic complementarities are low, while in the opposite case, it is optimal only if prices are sticky enough and the central bank holds sufficiently accurate information on the fundamentals of the economy. In the second essay, we use experimental macroeconomics to evaluate to what extent communication of the inflation target is relevant in an inflation targeting framework. Our results show that first, when the central bank only cares about inflation stabilization, announcing the inflation target does not make a difference in terms of macroeconomic performance compared to a standard active monetary policy. However, if the central bank also cares about the stabilization of the economic activity, communicating the target helps to reduce the volatility of inflation, interest rate, and output gap although their average levels are not affected. This finding provides a rationale for the adoption of flexible inflation targeting by the majority of inflation targeting countries. In the third essay, using a cross-sectional analysis and instrumental variables technique, we analyze the impact of central bank transparency on macroeconomic outcomes in emerging economies. We build a new index of transparency that combines some aspects of the overall Eijffinger and Geraats (2006) transparency index, with those of monetary policy committee transparency developed in Hayo and Mazhar (2011). We then analyze the individual role of each component of the new index in mitigating inflation and its volatility, as well as output volatility. By contrast to the previous literature, we interestingly find that the overall new index of transparency as well as its political, economic, procedural, and policy aspects negatively impact the average level of inflation, but not its volatility in these countries. The unique component of the new index that reduces the volatility of both inflation and output is operational transparency, and these results are robust to different econometric and instruments setting specifications.

Currently, more than half of all Swedish single-family houses have an installed heat pump and more heat is supplied by heat pumps in Sweden than in any other nation. Despite the enormous impact of heat pumps on the Swedish energy system, the transition towards their use has gone relatively unnoticed. Hence the title of this thesis, ‘A silent revolution’. This thesis provides an in-depth study of the Swedish transition towards heat pumps and how Swedish industries contributed to it. It approaches the topic from the perspective of value networks and ‘coopetition’, combined with the concept of complementarities. This approach has been inspired by the work of Verna Allee (2009) and Erik Dahmén (1991). In this thesis, value networks are networks of actors surrounding a specific business model, coopetition is used to describe the relationships between actors (as both competitive and cooperative), and the concept of complementarities is used to analyze the dynamics between synergistic elements and value networks in Sweden’s heat pump sector and energy system. Based on this approach, the thesis explains how a durable web of relations and interdependencies between complementarities has developed within the heat pump sector and the energy system in Sweden, and between the two, during the country’s transition to widespread use of heat pumps. Interest in heat pumps arose in Sweden and other parts of Europe during the 1970s. The Swedish energy system had been caught between international oil crises and national political mobilisation against nuclear power expansion. In this period of negative transformation pressure, the heat pump appeared as a promising alternative that could mitigate the use of oil and electricity for heating. In the 1970s, an early Swedish heat pump industry formed together with a growing heat pump market. A large number of diverse actors became involved in the Swedish heat pump sector, and the intense coopetition dynamics relating to heat pumps following the 1970s oil crisis contributed to durable connections between complementarities during the early stages of the transition. The 1980s saw a rapid expansion of large heat pumps in Swedish district heating facilities. In the mid-1980s, however, oil prices dropped back to their previous low levels. This change, combined with other factors, such as lifted subsidies and higher interest rates, created a crisis for Swedish heat pump industry. The industry underwent a 10-year period of low sales of small heat pumps and the market for large heat pumps died out and never returned. Nevertheless, several connections between heat pump–related complementarities remained in Sweden after the mid-1980s. In conjunction with value network reconfigurations, changes in company ownerships and governmental industry support, these complementarities helped the Swedish heat pump sector to maintain both production and service capacity. Due to developments that took place largely outside the heat pump manufacturing sector, by the mid-1990s it became possible for the struggling Swedish industry to offer more reliable and standardised heat pumps to the Swedish home heating market. During the years after 1995, the Swedish heat pump market grew to become the biggest in Europe. The industry’s early development and growth gave Swedish companies a comparative advantage over its European competitors, with the result that the manufacturing of heat pumps remained concentrated to Swedish-based manufacturing facilities even after the Swedish heat pump industry became internationalised after 2005. As of 2015, Sweden had the greatest amount of heat production from heat pumps per capita of any European nation, and many heat pump markets in other European countries are 10 to 20 years behind the Swedish market in development. This thesis shows how the Swedish heat pump industry has co-evolved with the market and how developments in the industry contributed towards causing the transition to heat pumps to occur so early in Sweden relative to other European markets. It also shows that coopetition dynamics in a socio-technical transition change with the emergence and characteristics of structural tensions between complementarities, which has implications for the strategic management of external relations and partnerships during socio-technical transitions. It further argues that the combination of the value network, coopetition, and complementarity concepts can be conceptualised for descriptive and exploratory studies on the role of firms and industries in socio-technical transitions, thereby offering a complement to existing dominant frameworks in the area of transition studies. / För närvarande har mer än hälften av alla svenska husägare en installerad värmepump. Värmepumpar levererar mer värme per capita i Sverige än i något annat land. Men trots värmepumparnas stora genomslag i det svenska energisystemet har övergången från olja och el till värmepumpar gått relativt obemärkt förbi. Därav titeln på denna avhandling, ”en tyst revolution”. Denna avhandling ger en djupgående beskrivning av den svenska övergången från olja och el till värmepumpar och av hur den svenska industrin bidragit till utvecklingen inom det svenska värmepumps- området. Forskningsansatsen i denna avhandling bygger på ett värdenätverks- och ’coopetition’-perspektiv i kombination med användningen av det dynamiska analytiska begreppet komplementaritet. Denna ansats är inspirerad av Verna Allees (2009) och Erik Dahméns (1991) arbeten. Begreppet värdenätverk används i denna avhandling för att beskriva det nätverk av aktörer som omger en specifik affärsmodell, begreppet ’coopetition’ används för att beskriva relationerna mellan aktörer (som både konkurrerande och samarbetande) och begreppet komplementaritet används för att analysera dynamiken mellan synergistiska delar och värdenätverk i den svenska värmepumpsektorn och det svenska energisystemet. Genom detta tillvägagångssätt beskrivs hur ett hållbart nät av relationer och ömsesidiga beroenden mellan komplementariteter har utvecklats, dels inom själva värmepumps- sektorn, dels mellan värmepumpssektorn och energisystemet i Sverige, under den svenska övergången mot ökad användning av värmepumpar. Intresset för värmepumpar steg i både Europa och Sverige under 1970- talet. Det svenska energisystemet var under tryck från både internationella oljekriser och nationell politisk mobilisering mot svensk kärnkrafts-utbyggnad. Under denna period när det svenska energisystemet var under negativt omvandlingstryck framstod värmepumpen som ett lovande alternativ som skulle kunna minska användningen av både olja och el för uppvärmning i Sverige. På 1970- talet bildades en svensk värmepumpindustri i samband med en växande värmepumpsmarknad. Ett stort antal aktörer av olika typer engagerade sig i den växande svenska värmepumpsektorn under denna period. Den intensiva samarbetsdynamiken kring värmepumpar som följde oljekrisen från 1970-talet bidrog till bildandet av varaktiga kopplingar mellan komplementariteter under denna tidiga fas i värmepumpsövergången. Under tidigt 1980-tal steg den relativa försäljningen av villavärmepumpar kraftigt och under mitten av 1980- talet skedde en ännu kraftigare utveckling av stora värmepumpar i svenska fjärrvärmeanläggningar. Men i mitten av 1980-talet sjönk oljepriset tillbaka till sina tidigare låga nivåer. I kombination med andra faktorer, så som slopade subventioner och höjd ränta, uppstod en kris för värmepumpar i Sverige. Den följande 10-års perioden karakteriserades av låg försäljning av små värmepumpar. Marknaden för stora värmepumpar försvann helt och skulle aldrig återkomma. Men flera kopplingar mellan värmepumpsrelaterade komplementarier kvarstod i Sverige även efter mitten av 1980-talet. I kombination med värdenätverkskonfigurationer, förändringar i företagsägande och statligt stöd till industrin, bidrog dessa hållbara kopplingar mellan komplementarier till att upprätthålla både produktion och servicefunktioner inom den svenska värmepumpsektorn. På grund av den tekniska utvecklingen, som i stor utsträckning skedde utanför tillverkningssektorn, blev det i mitten av 1990-talet möjligt för den kämpande svenska värmepumpsindustrin att erbjuda mer pålitliga och standardiserade villavärmepumpar till den svenska hemmamarknaden. Under åren efter 1995 växte den svenska värmepumpmarknaden till att bli den största i Europa. Den svenska marknadens och industrins utveckling och tillväxt gav svenska företag en relativ fördel gentemot sina eftersläntrande europeiska konkurrenter, med följden att tillverkningen av värmepumpar förblev koncentrerad till svenska anläggningar även efter det att en stor del av svensk värmepumpsindustri blivit uppköpt av utländska företag efter 2005. År 2015 var Sverige fortfarande det land med mest värme från värmepumpar per capita i Europa och den svenska utvecklingen var 10- 20 år före andra europeiska värmepumpmarknader. Denna avhandling beskriver samutvecklingen mellan den svenska värmepumpssektorn och det svenska energisystemet och hur den industriella utvecklingen bidragit till att den svenska övergången till värmepumpar var relativt tidig i jämförelse med andra europeiska marknader. Avhandlingen visar också att aktörsdynamiken i en socio- teknisk övergång förändras med uppkomsten av strukturella spänningar mellan komplementariteter, vilket har betydelse för hur externa relationer och partnerskap hanteras av företag och organisationer som genomgår omfattande socio-tekniska övergångar. Vidare argumenteras för att begreppen värdenätverk, coopetition, och komplementariteter kan kombineras i ett konceptuellt ramverk för att beskriva och analysera företags och industriers roller i omfattande socio-tekniska övergångar och därigenom komplettera nuvarande dominerande konceptuella ramverk för studier av omfattande socio-tekniska övergångar. / <p>QC 20171023</p>

Cette thèse est une collection de trois articles en économie de l'information. Le premier chapitre sert d'introduction et les Chapitres 2 à 4 constituent le coeur de l'ouvrage. Le Chapitre 2 porte sur l’acquisition d’information sur l’Internet par le biais d'avis de consommateurs. En particulier, je détermine si les avis laissés par les acheteurs peuvent tout de même transmettre de l’information à d’autres consommateurs, lorsqu’il est connu que les vendeurs peuvent publier de faux avis à propos de leurs produits. Afin de comprendre si cette manipulation des avis est problématique, je démontre que la plateforme sur laquelle les avis sont publiés (e.g. TripAdvisor, Yelp) est un tiers important à considérer, autant que les vendeurs tentant de falsifier les avis. En effet, le design adopté par la plateforme a un effet indirect sur le niveau de manipulation des vendeurs. En particulier, je démontre que la plateforme, en cachant une partie du contenu qu'elle détient sur les avis, peut parfois améliorer la qualité de l'information obtenue par les consommateurs. Finalement, le design qui est choisi par la plateforme peut être lié à la façon dont elle génère ses revenus. Je montre qu'une plateforme générant des revenus par le biais de commissions sur les ventes peut être plus tolérante à la manipulation qu'une plateforme qui génère des revenus par le biais de publicité. Le Chapitre 3 est écrit en collaboration avec Marc Santugini. Dans ce chapitre, nous étudions les effets de la discrimination par les prix au troisième degré en présence de consommateurs non informés qui apprennent sur la qualité d'un produit par le biais de son prix. Dans un environnement stochastique avec deux segments de marché, nous démontrons que la discrimination par les prix peut nuire à la firme et être bénéfique pour les consommateurs. D'un côté, la discrimination par les prix diminue l'incertitude à laquelle font face les consommateurs, c.-à-d., la variance des croyances postérieures est plus faible avec discrimination qu'avec un prix uniforme. En effet, le fait d'observer deux prix (avec discrimination) procure plus d'information aux consommateurs, et ce, même si individuellement chacun de ces prix est moins informatif que le prix uniforme. De l'autre côté, il n'est pas toujours optimal pour la firme de faire de la discrimination par les prix puisque la présence de consommateurs non informés lui donne une incitation à s'engager dans du signaling. Si l'avantage procuré par la flexibilité de fixer deux prix différents est contrebalancé par le coût du signaling avec deux prix différents, alors il est optimal pour la firme de fixer un prix uniforme sur le marché. Finalement, le Chapitre 4 est écrit en collaboration avec Sidartha Gordon. Dans ce chapitre, nous étudions une classe de jeux où les joueurs sont contraints dans le nombre de sources d'information qu'ils peuvent choisir pour apprendre sur un paramètre du jeu, mais où ils ont une certaine liberté quant au degré de dépendance de leurs signaux, avant de prendre une action. En introduisant un nouvel ordre de dépendance entre signaux, nous démontrons qu'un joueur préfère de l'information qui est la plus dépendante possible de l'information obtenue par les joueurs pour qui les actions sont soit, compléments stratégiques et isotoniques, soit substituts stratégiques et anti-toniques, avec la sienne. De même, un joueur préfère de l'information qui est la moins dépendante possible de l'information obtenue par les joueurs pour qui les actions sont soit, substituts stratégiques et isotoniques, soit compléments stratégiques et anti-toniques, avec la sienne. Nous établissons également des conditions suffisantes pour qu'une structure d'information donnée, information publique ou privée par exemple, soit possible à l'équilibre. / This thesis is a collection of three essays in economics of information. Chapter 1 is a general introduction and Chapters 2 to 4 form the core of the thesis. Chapter 2 analyzes information dissemination on the Internet. Online platforms such as Amazon, TripAdvisor or Yelp are now key sources of information for modern consumers. The proportion of consumers consulting online reviews prior to purchasing a good or a service has grown persistently. Yet, sellers have been accused of hiring shills to post fake reviews about their products. This raises the question: Does the presence of shills make reviews less informative? I show that the answers to this question depend on the way the platform presents and summarizes reviews on its website. In particular, I find that withholding information by garbling the reviews benefits information dissemination by inducing the seller to destroy less information with manipulation. Next, I show that the platform's choice regarding how to present reviews hinges on its revenue source. Indeed, a platform that receives sales commissions optimally commits to publishing information differently from a platform that receives revenues from advertisements or from subscription fees. Incidentally, such platforms have contrasting impacts on the amount of information that is transmitted by reviews. Chapter 3 is co-authored with Marc Santugini. In this chapter, we study the impact of third-degree price discrimination in the presence of uninformed buyers who extract noisy information from observing prices. In a noisy learning environment, it is shown that price discrimination can be detrimental to the firm and beneficial to the consumers. On the one hand, discriminatory pricing reduces consumers’ uncertainty, i.e., the variance of posterior beliefs upon observing prices is reduced. Specifically, observing two prices under discriminatory pricing provides more information than one price under uniform pricing even when discriminatory pricing reduces the amount of information contained in each price. On the other hand, it is not always optimal for the firm to use discriminatory pricing since the presence of uninformed buyers provides the firm with the incentive to engage in noisy price signaling. Indeed, if the benefit from price flexibility (through discriminatory pricing) is offset by the cost of signaling quality through two distinct prices, then it is optimal to integrate markets and to use uniform pricing. Finally, Chapter 4 is co-authored with Sidartha Gordon. In this chapter, we study a class of games where players face restrictions on how much information they can obtain on a common payoff relevant state, but have some leeway in covertly choosing the dependence between their signals, before simultaneously choosing actions. Using a new stochastic dependence ordering between signals, we show that each player chooses information that is more dependent on the information of other players whose actions are either isotonic and complements with his actions or antitonic and substitutes with his actions. Similarly, each player chooses information that is less dependent on the information of other players whose actions are antitonic and complements with his actions or isotonic and substitutes with his actions. We then provide sufficient conditions for information structures such as public or private information to arise in equilibrium.