This thesis comprises four essays in the economics of networks and market design. The common thread in all these essays is the presence of complementarities or externalities. Chapter 2 presents a unified model of networks and matching markets. We build on a contribution by Pycia (2012). We show that strong pairwise alignment of agents’ preferences is a necessary and sufficient condition for the existence of strongly stable networks and strongly stable allocations in multilateral matching markets with finite contracts. Strongly stable networks are not necessarily efficient. Although we use a demanding stability concept, strong pairwise alignment allows for complementarities and externalities. In Chapter 3, we generalise the gross substitutes and complements condition introduced by Sun and Yang (2006). Our new condition guarantees the existence of competitive equilibrium in economies with indivisible goods. Competitive equilibrium can be found using an extension of the double-track adjustment process (Sun and Yang, 2009). In this chapter, we also study contract networks (Ostrovsky, 2008). We show that chain-stable contract allocations can exist even in cyclical contractual networks, such as electricity markets, as long as they are appropriately segmented. In Chapter 4, we run a series of experiments to compare the performance of four auctions – first-price, Vickrey, Vickrey-Nearest Rule (Day and Cramton, 2008), and Reference Rule (Erdil and Klemperer, 2010). In our setting, there are two items and three bidders. Two local bidders want an item each, but the global bidder wants both items. We introduce various exposure and package-bidding treatments. We find that the first-price auction always revenue-dominates all the other auctions without any loss in efficiency, strengthening the results of Marszalec (2011). Exposure affects global bidders only in the first-price auction. In other auctions, global bidders often do not take into account the effect of their own bids on their payments. We find no evidence of threshold effects. Finally, in Chapter 5, we develop a new model of online social network formation. In this model, agents belong to many overlapping social groups. We derive analytical solutions for the macroscopic properties of the network, such as the degree distribution. We study the dynamics of homophily – the tendency of individuals to associate with those similar to themselves. We calibrate our model to Facebook data from ten American colleges.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2017-06-26T16:31:53Z No. of bitstreams: 1 Fernando Henrique Pisa_.pdf: 2123760 bytes, checksum: f1313904225dc8e30c5546bf6efbec19 (MD5) / Made available in DSpace on 2017-06-26T16:31:53Z (GMT). No. of bitstreams: 1 Fernando Henrique Pisa_.pdf: 2123760 bytes, checksum: f1313904225dc8e30c5546bf6efbec19 (MD5) Previous issue date: 2017-03-21 / Nenhuma / O objetivo principal das inovações sociais é criar soluções que possam ser replicáveis para enfrentar problemas complexos e que possuam relevância social, como é o caso da área da saúde. A visão estratégica do design e da lógica de redes de projeto, quando orientados para a inovação social, podem apresentar caminhos para sustentar e disseminar ideias e soluções viáveis tecnicamente, mas com dificuldade na difusão e ganho de escala, por depender tanto de aspectos técnicos, quanto de sociais. Utilizando o Programa de Telemedicina para o AVC, implementado no Rio Grande do Sul, como unidade de análise, este trabalho tem como meta analisar as contribuições do Design Estratégico para projetos de inovação social que tenham como foco atingir ganho de escala por meio de uma atuação baseada na lógica de sistemas distribuídos. Para tanto, desenvolveu-se uma pesquisa-ação na qual participaram, além do pesquisador, que também é gestor do Programa de Telemedicina, atores relevantes da Rede AVC, a fim de propor um novo modelo de telemedicina para a Rede. Os resultados obtidos sugerem a abordagem do design como ativadora da estratégia em projetos de inovação social, capaz de ampliar o entendimento do contexto e dos conflitos culturais existentes, de propor ações rápidas de engajamento dos atores e novos modelos, que sejam mais provocadores e eficientes em relação aos atuais. / The major goal of social innovations is to build solutions that can be replicable to face complex problems, and that have social relevance, as in the case of health field. Design’s strategic view, and design networks, when oriented for social innovation, can display ways to sustain and spread ideas and solutions technically feasible, but facing troubles in propagation and scale gains for its dependence of both technical and social aspects. Using Telestroke Program, implemented in Rio Grande do Sul, as unit of analysis, this research has as aim to analyze the contributions of Strategic Design for social innovation projects that have as purpose to reach scale gains by means of acting based in the distributed systems logic. For this, it was developed an action research in which took part, besides the researcher, who is as well the manager of the telemedicine program, relevant actors of the Stroke Network, in order to offer a new telemedicine model for the Network. Research outcomes point the Design’s approach as strategy activator in social innovations projects, capable of enlarge the understanding about the context and the existing cultural conflicts, of propose quick actions to engage actors and new models, that are more provocative and efficient regarding the reigning ones.

Submitted by William Justo Figueiro (williamjf) on 2015-07-08T23:00:52Z No. of bitstreams: 1 14b.pdf: 24498229 bytes, checksum: ec699a354ffbcf3b557be1b79222896d (MD5) / Made available in DSpace on 2015-07-08T23:00:52Z (GMT). No. of bitstreams: 1 14b.pdf: 24498229 bytes, checksum: ec699a354ffbcf3b557be1b79222896d (MD5) Previous issue date: 2013-03-26 / UNISINOS - Universidade do Vale do Rio dos Sinos / A era da informação trouxe mudanças essenciais nos sistemas de produção, distribuição e consumo. Essas transformações têm conduzido a mudanças nos processos de Design, hoje desenvolvidos por redes de projeto cada vez mais complexas: amplas, abertas, interdisciplinares, interfuncionais e interoganizacionais. Nesse contexto, a técnica de construção de cenários pode ser particularmente útil para aproximar os diversos atores ao redor de determinadas questões facilitando o compartilhamento de informação e a elaboração colaborativa de conhecimentos projetuais. Apesar da prática disciplinar já usar essa técnica difusamente, ainda são raros os estudos que enfrentam a construção de cenários especificamente dentro dos limites do processo projetual. Com isso, o objetivo geral desta pesquisa é discutir os processos de projetação por cenário à luz das transformações sociais, tecnológicas e, consequentemente, disciplinares. Para tanto, a estratégia da pesquisa-ação foi escolhida para observar ativamente o desempenho dos atores ao longo dos processos de construção de cenários. As atividades de pesquisa e projeto foram desenvolvidas junto ao Projeto Rede Sow. Trata-se de um projeto colaborativo que envolve o desenvolvimento tecnológico de uma plataforma web para o compartilhamento de informações entre os moradores de uma comunidade local. O projeto é coordenado pelo Pólo de Inovação Tecnológica do Vale do Paranhana - Encosta da Serra e pelas Faculdades Integradas de Taquara com recursos da Secretaria da Ciência, Inovação e Desenvolvimento Tecnológico do RS. A discussão realizada neste trabalho buscou contemplar aspectos relacionados ao significado e aos processos associados aos cenários para avançar na direção de uma tecnologia capaz de mediar a complexidade das redes de projeto colaborativas. Como resultados observa-se que os cenários podem ser entendidos como um evento capaz de incluir as interações entre os atores nos processos de co-design. Além disso, o trabalho evidenciou que o uso dos cenários pode caracterizar uma estratégia projetual específica. Discutiu-se a respeito do "projeto por cenários", uma tecnologia que pode catalisar o caráter estratégico do design com técnicas de construção especialmente focadas na flexibilidade. / The evolving information age has brought essential changes in production, distribution and consumption systems. Such transformation has conducted to changes in design processes, currently developed by complex design networks: they are open, interdisciplinary, cross-functional and interorganizational. In said context, scenario building techniques might be particularly useful for approaching the many actors involved towards certain issues as it aids the sharing of information and the elaboration of collaborative design knowledge. Even though the discipline diffusely employs this method, studies lack to refer to scenario building within the limits set out to design processes. Therefore, the main objective of this research is to discuss scenario building processes from the perspective of social, technological and disciplinary transformations. For that reason, an action-research strategy was chosen to allow active observation of the actors’ performance while building scenarios. Research and project were developed along the Sow Network Project, which is a collaborative enterprise focusing on the technological development of a web platform that allows information sharing among residents of a local community. The project is coordinated by a regional Technology Innovation Cluster (Pólo de Inovação Tecnológica do Vale do Paranhana – Encosta da Serra) and a local college (Faculdades Integradas de Taquara), and is funded by Rio Grande do Sul’s Department of Sciences, Innovation and Technologic Development. The reflections accomplished in this research contemplate issues associated with meaning and scenario building processes towards achieving a technology that enables mediating the complexity of collaborative design networks. As for the results, we have observed that scenarios could be understood as events that include interaction among the actors in codesign processes. Furthermore, it was evidenced that scenario practices are able to define a specific design strategy. The idea of “designing through scenarios” was discussed, as it is a technology that might catalyze the strategic feature of design by using building methods mainly focused on flexibility.