An example of strategic market game with infinitely many commodities

This short paper shows in an example of strategic market game that the CournotNash equilibrium converges to the Walras equilibrium, even in the case of an exchange economy with infinitely many commodities

Strategic foundations of oligopolies in general equilibrium

In this thesis, I study the strategic foundations of oligopolies in general equilibrium by following the approach based on strategic market games. The thesis is organised as follows. In Chapter 1, I first survey some of the main contributions on imperfect competition in production economies and the main problems which arise in this framework. I then focus on the literature on imperfect competition in exchange economies by considering the Cournot-Walras approach and strategic market games. I finally discuss the main contributions on the foundations of oligopolies. In Chapter 2, I extend the non-cooperative analysis of oligopoly to exchange economies with infinitely many commodities and traders by using a strategic market game with trading posts. I prove the existence of a Cournot-Nash equilibrium with trade and show that the price vector and the allocation at the Cournot-Nash equilibrium converge to the Walras equilibrium when the number of traders increases. In a framework with infinitely many commodities, an oligopolist can be an "asymptotic oligopolist" if his market power is uniformly bounded away from zero on an infinite set of commodities, or an "asymptotic price-taker" if his market power converges to zero along the sequence of commodities. The former corresponds to the Cournotian idea of oligopolist. The latter describes an agent with a kind of mixed behaviour since his market power can be made arbitrary small by choosing an appropriate infinite set of commodities while it is greater than a positive constant on a finite set. In Chapter 3, I further study oligopolies in economies with infinitely many commodities and traders. By using the strategic market game called "all for sale model", I prove the existence of an asymptotic price-taker. Heuristically, an asymptotic price-taker exists if at least one trader makes positive bids on an infinite number of commodities and in all markets the quantities of commodities exchanged are non-negligible. In Chapter 4, I study if there is a non-empty intersection between the sets of Cournot-Nash and Walras allocations in mixed exchange economies, with oligopolists represented as atoms and small traders represented by a continuum. In a bilateral oligopoly setting, I show that a necessary and sufficient condition for a Cournot-Nash allocation to be a Walras allocation is that all atoms demand a null amount of one of the two commodities. I also provide four examples which show that this characterization holds non-vacuously

Correction to : An introduction to perfect and imperfect competition via bilateral oligopoly (Journal of Economics, (2021), 133, 2, (103-128), 10.1007/s00712-020-00727-3)

In the original version of this article, all maximization problems appears incorrectly. The original article can be found at the doi https://doi.org/10.1007/s00712-020- 00727-3. The original article has been corrected

An introduction to imperfect competition via bilateral oligopoly

The aim of this paper is threefold. First, we provide a unified framework, by means of non-trivial examples, to compare the results obtained in simultaneous-move and sequential-move versions of bilateral oligopoly with the Cournot model and the Cournot-Walras approach. We also survey the main contributions on imperfect competition and strategic market games that are linked with our analysis. Secondly, we show how the bilateral oligopoly model can be used to study different kinds of oligopoly: symmetric oligopoly, where all agents act strategically; asymmetric oligopoly where only some agents act strategically; simultaneous oligopoly, where sellers and buyers make their choices without knowledge of others' decisions; and sequential oligopoly, where some agents move first. Thirdly, we focus on how the bilateral oligopoly model can clarify how either strategic or competitive behaviours may emerge endogenously depending on the fundamentals of the economy

Chronic graft-versus-host-disease-related polymyositis: a 17-months-old child with a rare and late complication of haematopoietic stem cell transplantation

Background: Chronic graft versus host disease (cGVHD) occurs in 20-30% of paediatric patients receiving haemopoietic stem cell transplantation (HSCT). Neuromuscular disorders such as polymyositis are considered a rare and distinctive but non-diagnostic manifestation of cGVHD and, in the absence of other characteristic signs and symptoms, biopsy is highly recommended to exclude other causes. Case report: We report a case of a 17-months-old child affected by hemophagocytic lymphohistiocytosis who underwent a matched unrelated donor haematopoietic stem cell transplantation (HSCT). She developed severe cGVHD-related polymyositis that was successfully treated with high-dose steroid therapy, rituximab and sirolimus. Conclusions: This is the first case of cGVHD-related-polymyositis described in a pediatric patient which was successfully treated with rituximab

CONCENTRAÇÃO DO SETOR DE BASE FLORESTAL NO BRASIL: ESTUDO DE EVENTO DA FUSÃO DA FIBRIA E SUZANO

Este artigo objetivou verificar, a partir do Estudo de Eventos, a reação do mercado após o anúncio de fusão entre as empresas Suzano Papel e Celulose e a Fibria se tornando a Suzano S/A em 2019. Dentre os eventos corporativos, os processos de fusões e aquisições (F&A) encontram-se entre os que apresentam elevada complexidade e incerteza. Observou-se o desempenho normal do retorno das ações da empresa e as relacionou com o índice da Bolsa de Valores de São Paulo (B3). Objetivou-se averiguar a eficiência de mercado, a saber, eficiência informal, semiforte, e apresentar que os retornos anormais gerados das notícias de Fusões e Aquisições são maiores do que os esperados pelo modelo tomando em consideração os retornos médios no período que antecedem o evento. E a partir da metodologia dos Retornos Anormais Acumulado foi possível observar que o retorno anormal apresentado logo após esse anúncio foi obtido devido este evento

Da aplicabilidade do código de defesa do consumidor nos contratos eletrônicos

O trabalho aqui divulgado, pretende mostrar que as normas dispostas no Código de Defesa do Consumidor são aplicáveis aos contratos celebrados através da Internet, nos quais uma das partes é o fornecedor estrangeiro, e a outra, o consumidor domiciliado no território brasileiro, tendo em vista a falta de legislação específica no ordenamento jurídico nacional

A evolução dos direitos autorais na internet

Através da criatividade humana nasceram as obras intelectuais e com o desenvolvimento cultural e tecnológico da humanidade surgiu a necessidade de proteger essas criações do intelecto, razão pela qual nasceram os direitos de Propriedade Intelectual, que se subdividem em direitos autorais e direitos de propriedade industrial. Com o crescimento desenfreado da Internet, observa-se um descaso com os Direitos Autorais das obras veiculadas na rede, desrespeitando a tutela que as legislações vêm dando aos criadores destas obras. Assim, o presente ensaio pretende demonstrar uma breve análise feita sobre o surgimento dos Direitos Autorais e sua aplicação na Grande Rede