Esta tese é composta por três ensaios relacionados a macrofinanças e economia regional. O primeiro artigo analisa a lucratividade de portfólios de pairs trading auto-financiados para os mercados acionários Brasileiro, Europeu e Americano utilizando duas metodologias diferentes de seleção de pares: os métodos da distância e cointegração. Uma comparação ampla das metodologias de pairs trading, com uma base de dados grande de diferentes mercados é capaz de elucidar os principais benefícios e fragilidades de cada método. De modo geral, os resultados mostram que diferentes estruturas de mercado favorecem diferentes estratégias de pairs trading. Mais especificamente, a seleção via cointegração desempenha melhor nos mercados Brasileiro e Europeu, enquanto que o método da distância gera resultados melhores para os Estados Unidos. A melhor estratégia em cada mercado possui um alpha significante com um beta negligenciável. No segundo trabalho analisamos duas questões: (i) a capacidade do Brasil em adotar uma política monetária independente das influências dos juros americanos e (ii) os impactos da política monetária brasileira e dos juros americanos nas expectativas de inflação. Os resultados indicam que, para o período entre 1999 e 2007, existe uma reduzida independência da política monetária brasileira, e que o contágio do Fed Funds rate sobre a taxa Selic ocorre de modo completo. Para o período entre 2002 e 2007, também encontramos que os juros americanos são mais relevantes para a determinação das expectativas de inflação do que a taxa Selic, sendo auxiliado pelo câmbio para controlar as expectativas de inflação. Por outro lado, no período entre 2010 e início de 2015, com a ausência de mudanças no Fed Funds, a Selic se tornou mais independente e reativa, tanto às expectativas de inflação quanto ao hiato do produto. O terceiro artigo consiste em recalcular a MIP para o Rio Grande do Sul e para o Brasil a fim de incluir nas interligações setoriais os efeitos induzidos advindos da renda das famílias. Além disso, calculam-se os geradores de cinco variáveis (a saber: emprego, renda, tributos líquidos arrecadados, valor adicionado e produto), bem como são calculados os índices de Hirschmann-Rasmussen e os índices puros de ligação com o intuito de identificar os setores-chave das economias do Rio Grande do Sul e do Brasil. Posteriormente, utiliza-se dos geradores reestimados pela nova MIP fechada para estimar os impactos das quebras de safra de soja nos anos que ocorreram as maiores perdas tanto de valor quanto de volume na produção da oleaginosa (2004, 2005 e 2012). Os resultados indicam que os geradores do Rio Grande do Sul e do Brasil aumentam consideravelmente após a inclusão do efeito induzido, para todas as variáveis e setores analisados. Já as estimativas de impacto das quebras de safra indicam que as perdas podem chegar a até R$ 8,9 Bilhões para o RS e R$ 12,5 Bilhões para o Brasil em termos de queda na produção. / This thesis consists of three essays related to financial macroeconomics and regional economics. The first essay analyzes the profitability of self-financing portfolios using pairs trading for the Brazilian, European, and American stock markets using two different pairs selection methodologies: the distance and cointegration methods. A throughout comparison of pairs trading methodologies using large datasets from different markets uncovers the main benefits and drawbacks of each approach. Overall, the results show that different market structures favor different pairs trading strategies. More specifically, the cointegration approach performed better on the Brazilian and European markets, while the distance method delivered better results for the US. The best strategy in each market yields significant alpha with negligible beta. The ability of a country to use monetary policy in order to smooth economic fluctuations and keep inflation in check is crucial in an institutional framework of inflation targeting. Hence, in the second work, we examined two issues: (i) Brazil’s ability to adopt a monetary policy independent from the contagion of the american interest rates and (ii) the impact of the brazilian monetary policy and of the american interest rate on inflation expectations. The results indicate that for the period between 1999 and 2007, there is a reduced independence of the brazilian monetary policy, and that the spillover of the Fed Funds rate over the Selic rate is comprehensive. For the period between 2002 and 2007, we also found that US interest rates are more relevant to the determination of inflation expectations than the Selic rate, being helped by the exchange rate to control inflation expectations. On the other hand, for the period between 2010 and early 2015, with no occurance of changes in the Fed Funds, the Selic became more independent and responsive to inflation expectations as well as to the output gap. The third paper consist of reestimating the Input-Output Matrix for Rio Grande do Sul and Brazil, in order to include in the sectoral linkages the induced effects arising from household income. Also, we estimate the multipliers for five variables (employment, income, net taxes collected, added value and gross product), as well as the Hirschmann-Rasmussen index and the Pure Linkages in order to identify the key-sectors of the Rio Grande do Sul and Brazil’s economy. We also use those multipliers to estimate the impacts of the soybean crop failure in Rio Grande do Sul, in the years with the biggest crop losses in terms of volume (2004, 2005 and 2012). The results indicate that the multipliers increase considerably after the inclusion of the induced effect, for all valiables and sectors. The crop failures indicate that the losses could reach up to R$ 8,9 Billions for RS and R$ 12,5 Billions for Brasil in terms of reduced economic activity.

La médiation est devenue un moyen privilégié pour régler des nombreux conflits, notamment ceux en rapport avec le commerce, et plus particulièrement avec le commerce international. Sur le plan national, les parties en conflit préfèrent souvent ce moyen pour régler leur conflit à chaque fois que la loi ne s’y oppose pas. Ceci est dû à plusieurs raisons dont la plus importante est liée à la lenteur de la justice. Sur le plan international, des nombreux pays, notamment ceux en voie de développement, ne sont en mesure d’attirer des investissements des capitaux étrangers que s’ils considèrent la médiation comme moyen de règlement des conflits. L’avantage de ce moyen réside dans le fait que la médiation est rapide, simple et permet au justiciable d’obtenir ses droits de façon aisée. Ces caractéristiques de la médiation restent valables du point de vue théorique. Mais en pratique, les choses sont plus compliquées et peuvent gêner le déroulement de l’arbitrage, par exemple. Prenons en exemple les conflits civils dont le règlement nécessite souvent la mise en œuvre de certaines actions qui conduisent effectivement à la solution du conflit en question. Cette initiative de mise en œuvre de l’action n’ est pas réservée aux parties de conflits . Mais, l’organisme habilité à résoudre le conflit peut également prendre cette initiative seul, ou à la demande d’une de deux parties . Ces mesures et actions décidées par un tribunal ou par une médiation représentent le facteur temps dans le règlement des conflits. C’est à ce moment-là que peuvent apparaître les difficultés qui sont en rapport soit avec le déroulement du conflit lui- même, soit avec l’exécution du jugement prononcé. Ce moyen pour régler les conflits mérite bien d’être privilégié car, d’une part il peut effectivement mettre fin au conflit et d’autre part il peut avoir les mêmes forces que le jugement d’un tribunal. Pour ces raisons, les protagonistes le préfèrent. Nous avons donc choisi ce sujet du facteur temps dans la médiation pour les raisons suivantes : *illustrer le facteur temps dans la médiation puisqu’il s’agit d’un élément indissociable du sujet du conflit qui fait l’objet de la médiation même ; *Définir la partie qui a en charge le règlement de ce genre de conflits suivant les règles juridiques de références et explorer la complétude de ces règles pour pouvoir ensuite dire dans quelle direction doit être dirigé le règlement du conflit : vers la médiation ou vers la justice ? / Mediation has become a preferred way to resolve many conflicts, including those related to international trade. Nationally, the conflicting party often prefer this method to resolve their dispute whenever the law requires otherwise pas.Ceci is due to several reasons, the most important being the slow pace of justice. Internationally, many countries, particularly those in developing countries, are able to benefit from investments of foreign capital that they consider mediation as a dispute resolution means .l'avantage this means is that that mediation is a fast, simple and allows litigants to obtain their rights easily. These characteristics of mediation are still valid théorique.Mais perspective in practice, things are more complicated and may interfere with the conduct of mediation if, in his objet.Prenons example civil conflict whose resolution often requires implementation certain actions that actually lead to the solution of the conflict in question. This initiative implementation of the action is not limited to parts of conflits.Mais, the body authorized to resolve the conflict can also take this one initiative or at the request of one of two parts. These measures and actions decided by a court or mediation are the time factor in conflict resolution. It was at this time that may appear difficulties are related either the conduct of the conflict itself Even either the conduct of the implementation of the judgment delivered.

Nesta tese discutimos abordagens que utilizam cópulas para descrever dependências entre instrumentos nanceiros e avaliamos a performance destes métodos. Muitas crises nanceiras aconteceram desde o nal da década de 90, incluindo a crise asiática (1997), a crise da dívida da Rússia (1998), a crise da bolha da internet (2000), as crises após o 9/11 (2001) e a guerra do Iraque (2003), a crise do subprime or crise nanceira global (2007-08), e a crise da dívida soberana europeia (2009). Todas estas crises levaram a uma perda maciça de riqueza nanceira e a um aumento da volatilidade observada, e enfatizaram a importância de uma política macroprudencial mais robusta. Em outras palavras, perturbações nanceiras tornam os processos econômicos altamente não-lineares, levando os principais bancos centrais a tomarem medidas contrárias para conter a angústia - nanceira. Devido aos complexos padrões de dependência dos mercados nanceiros, uma abordagem multivariada em grandes dimensões para a análise da dependência caudal é seguramente mais perspicaz do que assumir retornos com distribuição normal multivariada. Dada a sua exibilidade, as cópulas são capazes de modelar melhor as regularidades empiricamente veri cadas que são normalmente atribuídas a retornos nanceiros multivariados: (1) volatilidade condicional assimétrica com maior volatilidade para grandes retornos negativos e menor volatilidade para retornos positivos (HAFNER, 1998); (2) assimetria condicional (AIT-SAHALIA; BRANDT, 2001; CHEN; HONG; STEIN, 2001; PATTON, 2001); (3) excesso de curtose (TAUCHEN, 2001; ANDREOU; PITTIS; SPANOS, 2001); e (4) dependência temporal não linear (CONT, 2001; CAMPBELL; LO; MACKINLAY, 1997). A principal contribuição dos ensaios é avaliar se abordagens mais so sticadas do que o método da distância e o tradicional modelo de Markowitz podem tirar proveito de quaisquer anomalias/fricções de mercado. Os ensaios são uma tentativa de fornecer uma análise adequada destas questões usando conjuntos de dados abrangentes e de longo prazo. Empiricamente, demonstramos que as abordagens baseadas em cópulas são úteis em todos os ensaios, mostrando-se bené cas para modelar dependências em diferentes cenários, avaliando as medidas de risco caudais mais adequadamente e gerando rentabilidade superior a dos benchmarks utilizados. / In this thesis we discuss copula-based approaches to describe statistical dependencies within nancial instruments and evaluate its performance. Many nancial crises have occurred since the late 1990s, including the Asian crisis (1997), the Russian national debt crisis (1998), the dot-com bubble crisis (2000), the crises after 9-11 (2001) and Iraq war (2003), the subprime mortgage crisis or global nancial crisis (2007-08), and the European sovereign debt crisis (2009). All of these crises lead to a massive loss of nancial wealth and an upward in observed volatility and have emphasized the importance of a more robust macro-prudential policy. In other words, nancial disruptions make the economic processes highly nonlinear making the major central banks to take counter-measures in order to contain nancial distress. The methods for modeling uncertainty and evaluating the market risk on nancial markets are now under more scrutiny after the global nancial crisis. Due to the complex dependence patterns of nancial markets, a high-dimensional multivariate approach to tail dependence analysis is surely more insightful than assuming multivariate normal returns. Given its exibility, copulas are able to model better the empirically veri ed regularities normally attributed to multivariate nancial returns: (1) asymmetric conditional volatility with higher volatility for large negative returns and smaller volatility for positive returns (HAFNER, 1998); (2) conditional skewness (AITSAHALIA; BRANDT, 2001; CHEN; HONG; STEIN, 2001; PATTON, 2001); (3) excess kurtosis (TAUCHEN, 2001; ANDREOU; PITTIS; SPANOS, 2001); and (4) nonlinear temporal dependence (CONT, 2001; CAMPBELL; LO; MACKINLAY, 1997). The principal contribution of the essays is to assess if more sophisticated approaches than the distance method and plain Markowitz model can take advantage of any market anomalies/ fricctions. The essays are one attempt to provide a proper analysis in these issues using a long-term and comprehensive datasets. We empirically show that copula-based approaches are useful in all essays, proving bene cial to model dependencies in di erent scenarios, assessing the downside risk measures more adequately and yielding higher profitability than the benchmarks.

The purpose of this thesis is: (i) to produce an in-depth data analysis and computer-based simulations of the market environment to investigate whether financial stability is affected by the presence of High-Frequency investors; (ii) to verify how High-Frequency Trading and financial stability interact with each other under non-linear conditions; (iii) whether non-illicit behaviours can still lead to potentially destabilising effects; (iv) to provide quantitative support to the theses, either from the audit trail data or resulting from simulations. Simulations are provided to test whether High-Frequency Trading: (a) has an impact on market volatility, (b) leads to market splitting into two tiers; (c) takes the lion's share of arbitrage opportunities. Audit trail data is analysed to verify some hypotheses on the dynamics of the Flash Crash. The simulation on the impact of High-Frequency Trading on market volatility confirms that when markets are under stress, High-Frequency Trading may cause volatility to significantly increase. However, as the number of ultra-fast participants increases, this phenomenon tends to disappear and volatility realigns to its standard values. The market tiering simulation suggests that High-Frequency traders have some tendency to deal with each other, and that causes Low-Frequency traders also to deal with other slow traders, albeit at a lesser extent. This is also a kind of market instability. High-Frequency Trading potentially allows a few fast traders to grab all the arbitrage-led profits, so falsifying the Efficient Market Hypothesis. This phenomenon may disappear as more High-Frequency traders enter the competition, leading to declining profits. Yet, the whole matter seems a dispute for abnormal gains only between few sub-second traders. All simulations have been carefully designed to provide robust results: the behaviours simulated have been drawn from existing literature and the simplifying assumptions have been kept to a minimum. This maximises the reliability of the results and minimizes the potential of bias. Finally, from the data analysis, the impact of High-Frequency Trading on the Flash Crash seems significant; other sudden crashes occurred since, and more can be expected over the next future. Overall, it can be concluded that High-Frequency Trading shows some controversial aspects impacting on financial stability. The results are at a certain extent confirmed by the audit trail data analysis, although only indirectly, since the details allowing the match between High-Frequency traders and their behaviour are confidential and not publicly available Nevertheless, the findings about HFT-induced volatility, market segmentation and sub-optimal market efficiency, albeit not definitive, suggest that careful monitoring by regulators and policy-makers might be required.

De nos jours, les activités et les relations d'affaires sont beaucoup plus larges et complexes qu'auparavant. L'extension de cet espace, nécessite que les différends relatifs aux affaires commerciales soient réglés dans des systèmes efficaces adaptés à la nature des litiges de ce domaine, c'est-à-dire, rapidement, de manière précise et par des experts. C'est pour quoi, au cours des dernières décennies, les législations des pays relatives à l’arbitrage ont été actualisées, et les conventions internationales dans ce domaine connaissent une large réussite. Les pays recherchant à transformer leur législation sur l’arbitrage commercial disposent d’un modèle législatif apprécié et intéressant fourni par la loi type sur l’arbitrage commercial international ; il a été adopté en 1985 par la CNUDCI et constitue aujourd’hui une référence pour réaliser une unité juridique dans le domaine de l’arbitrage commercial international. Les transformations des régimes juridiques nationaux ont débuté assez tôt dans certains des pays développés tels la France, la Suisse et la Belgique, tandis qu’elles ont été entamées assez tardivement dans d’autres pays, tels ceux en voie de développement dont l’Iran. En Iran, l’arbitrage a toujours été admis et pratiqué ; néanmoins, la procédure civile iranienne présentait encore des insuffisances, et dévoila encore davantage de défauts concernant l’arbitrage international. En conséquence, les parties iraniennes aux contrats internationaux ne pouvaient convaincre les parties étrangères à accepter l’Iran en tant que place d’arbitrage. C’est en accord avec les évolutions législatives mondiales que l’Iran aussi, tout en se joignant à la Convention de New York de 1958, réforma sa législation sur l’arbitrage commercial international, en adoptant en 1997 une loi sur l’arbitrage commercial international rédigée en adoptant le modèle législatif proposé par la CNUDCI. Cette loi marqua une évolution marquante dans la législation iranienne vu qu’elle institua d’importantes règles alignées sur les tendances récentes du droit de l’arbitrage international. Malgré cela, certains praticiens y découvrirent des défauts et des lacunes, réclamant ainsi une réforme nécessaire pour rendre le droit iranien réellement attractif. Néanmoins, la loi iranienne de 1997 n’a jamais fait jusqu’à ce jour l’objet d’une étude scientifique systématique. L’examen des droits d'autres pays tels que : la français, la belge et l'anglais sur l’arbitrage commercial international, ainsi que l’étude d’autres sources pertinentes, permettra d’identifier et d’analyser en profondeur les lacunes et de proposer des remèdes. / Nowadays, the business relations are much broader and more complex than before. The extension of this area of activities requires the disputes arising out of business relationships to be resolved through the effective systems aligned with the nature of this area, i.e. the promptness, accuracy and expertise. Hence, over the last few decades, the national laws relating to the arbitration have been developed, and international conventions in this field achieved a great deal of success.The countries seeking to reform their legislation on commercial arbitration can adopt the well-known model law provided by the UNCITRAL Model Law on International Commercial Arbitration which has been adopted in 1985 by UNCITRAL and is now a reference for the realization of a legal system in the field of international commercial arbitration. Changes in national legal regimes began relatively early in some of the developed countries such as France, Switzerland and Belgium, while they were initiated fairly late in other countries, such as developing world, including Iran.In Iran, arbitration has always been admitted and practiced; nevertheless, the civil procedure in Iran was inadequate in this area, and revealed even more defects concerning international arbitration. Consequently, Iranian parties to international contracts could hardly convince their foreign parties to accept Iran as the seat of arbitration.It was in line with global legislative developments that Iran, while joining the 1958 New York Convention, has reformed its legislation on international commercial arbitration by adopting a law on commercial arbitration in 1997 in accordance with the model law proposed by UNCITRAL. This law marked a significant development in Iranian legislation as it established important rules aligned with recent trends in the law of international arbitration. Despite this, the practitioners discovered some defects and shortcomings. That’s why they call for a reform necessary to make Iranian law truly attractive. Nevertheless, the Iranian law of 1997 has never been subject of a comprehensive study so far. Examination of the laws of other countries such as French, Belgian and English on international commercial arbitration, as well as the study of other relevant sources, will pave the way to identify and analyze in depth the gaps and propose remedies.

Le droit des Affaires en Afrique se présente comme un labyrinthe en face duquel on manifeste des velléités à s’introduire. En effet, on y remarque une superposition de normes découlant d’une diversité d’instruments juridiques. Cette diversité n’est que la résultante d’une panoplie de zones économiques (UEMOA, CEMAC, CEDEAO notamment), une sorte de plusieurs unions européennes reposant sur deux systèmes juridiques fondamentaux qui coexistent : «Droit civil et Common Law». Il y a donc une difficulté, considérablement résorbée, mais loin d’être achevée liée à l’insécurité juridique voire judiciaire. Dans le but de constituer un point d’attraction aux investisseurs étrangers en particulier, et dans un souci de contribution à l’œuvre d’ «uniformisation» et non de simple harmonisation du droit des affaires qu’a amorcé le législateur de l’OHADA depuis le 17 octobre 1993 à Port-Louis en Ile-Maurice, en mettant en place le Traité constitutif de l’Organisation pour l’Harmonisation en Afrique du droit des Affaires, il nous paraît impératif et opportun d’élaborer et de consolider une théorie générale relative aux contrats. La théorie générale dans le cadre de nos travaux se limitera aux contrats d’affaires car nous partons du postulat que cette catégorie de contrats constitue le socle de toutes opérations économiques. La théorie générale des contrats d’affaires reviendrait alors à mettre en place un droit commun des contrats d’affaires dans l’espace OHADA. Ladite théorie générale des contrats d’affaires doit trouver son ancrage dans les dispositions préexistantes sans toutefois renoncer à l’introduction de nouvelles règles susceptibles de contribuer à son succès. Elles doivent cependant, afin d’être efficaces voire effectives, rester compatibles avec les différents Actes uniformes de l’OHADA, œuvre ingénieuse déjà accomplie par le législateur de l’OHADA et surtout ne pas rejeter l’héritage du système juridique français. Notre réflexion trouvera son socle dans une étude du droit positif de l’OHADA et français, et, du droit prospectif émanant des avant-projets du droit des contrats d’une part, mais également de divers autres instruments juridiques d’autre part, qui nous permettront d’établir les normes juridiques voire les mesures devant prévaloir dans les relations contractuelles d’affaires de l’OHADA, de faire ressortir l’homogénéité, l’unicité ou la diversité de ce système contractuel d’affaires, de faire remarquer la relation fidèle ou non qu’entretient l’OHADA avec le système juridique français. / The business Law in Africa appears as a labyrinth in front of which we show vague desires to get. Actually we notice a superimposing of resulting standards from a diversity of legal instruments. The diversity is the resultant of an outfit of economic zones (UEMOA,CEMAC, ECOWAS, in particular), a kind of several European unions based on two fundamental legal systems which coexist : Civil Law and Common law. So, there is a difficulty considerably reduced, but far from being finished inherent to the even judicial legal insecurity. With the aim of establishing a point of attraction to the foreign investors especially, and in a concern of contribution to the work of «standardization» and not simple harmonization of the business law which the legislator of OHADA has begun since October 17th 1993, at Port-Louis in Ile-Maurice, by setting up the Treaty of the Organization of the harmonization of Busines law in Africa, it seems to us imperative and convenient to develop and strenghen a general theory relative to contracts. The general theory within the framework of our researches will limit itself to business contracts because we start from the postulate that this category of contracts constitutes the base of any economic operations. The general theory of business contracts would then mean setting up a common law of business contracts in OHADA area. The aformentionned general theory of business contracts has to fin its anchoring in the pre-existent measures without giving up the introduction of new rules susceptible to contribute to its success. However they have to remain compatible with the various uniform Acts of the OHADA, the ingenious work already achieved by the legislator ofthe OHADA and especially not reject the inheritance of the french legal system in order to be effective. Our reflection will find its base in the study of substantive law of the OHADA and French, and, the forward-looking law emanating from drafts from the contract law on one hand, but also from miscellaneous other legal instruments on the other hand, which will allow us to establish the legal rules even the measures that must prevail in the contractual business relationsof the OHADA, to highlight the homogeneity, the uniqueness or the diversity of this contractual business system, to point out the faithful relation or not that the OHADA with the french legal system maintains.

Nesta tese discutimos abordagens que utilizam cópulas para descrever dependências entre instrumentos nanceiros e avaliamos a performance destes métodos. Muitas crises nanceiras aconteceram desde o nal da década de 90, incluindo a crise asiática (1997), a crise da dívida da Rússia (1998), a crise da bolha da internet (2000), as crises após o 9/11 (2001) e a guerra do Iraque (2003), a crise do subprime or crise nanceira global (2007-08), e a crise da dívida soberana europeia (2009). Todas estas crises levaram a uma perda maciça de riqueza nanceira e a um aumento da volatilidade observada, e enfatizaram a importância de uma política macroprudencial mais robusta. Em outras palavras, perturbações nanceiras tornam os processos econômicos altamente não-lineares, levando os principais bancos centrais a tomarem medidas contrárias para conter a angústia - nanceira. Devido aos complexos padrões de dependência dos mercados nanceiros, uma abordagem multivariada em grandes dimensões para a análise da dependência caudal é seguramente mais perspicaz do que assumir retornos com distribuição normal multivariada. Dada a sua exibilidade, as cópulas são capazes de modelar melhor as regularidades empiricamente veri cadas que são normalmente atribuídas a retornos nanceiros multivariados: (1) volatilidade condicional assimétrica com maior volatilidade para grandes retornos negativos e menor volatilidade para retornos positivos (HAFNER, 1998); (2) assimetria condicional (AIT-SAHALIA; BRANDT, 2001; CHEN; HONG; STEIN, 2001; PATTON, 2001); (3) excesso de curtose (TAUCHEN, 2001; ANDREOU; PITTIS; SPANOS, 2001); e (4) dependência temporal não linear (CONT, 2001; CAMPBELL; LO; MACKINLAY, 1997). A principal contribuição dos ensaios é avaliar se abordagens mais so sticadas do que o método da distância e o tradicional modelo de Markowitz podem tirar proveito de quaisquer anomalias/fricções de mercado. Os ensaios são uma tentativa de fornecer uma análise adequada destas questões usando conjuntos de dados abrangentes e de longo prazo. Empiricamente, demonstramos que as abordagens baseadas em cópulas são úteis em todos os ensaios, mostrando-se bené cas para modelar dependências em diferentes cenários, avaliando as medidas de risco caudais mais adequadamente e gerando rentabilidade superior a dos benchmarks utilizados. / In this thesis we discuss copula-based approaches to describe statistical dependencies within nancial instruments and evaluate its performance. Many nancial crises have occurred since the late 1990s, including the Asian crisis (1997), the Russian national debt crisis (1998), the dot-com bubble crisis (2000), the crises after 9-11 (2001) and Iraq war (2003), the subprime mortgage crisis or global nancial crisis (2007-08), and the European sovereign debt crisis (2009). All of these crises lead to a massive loss of nancial wealth and an upward in observed volatility and have emphasized the importance of a more robust macro-prudential policy. In other words, nancial disruptions make the economic processes highly nonlinear making the major central banks to take counter-measures in order to contain nancial distress. The methods for modeling uncertainty and evaluating the market risk on nancial markets are now under more scrutiny after the global nancial crisis. Due to the complex dependence patterns of nancial markets, a high-dimensional multivariate approach to tail dependence analysis is surely more insightful than assuming multivariate normal returns. Given its exibility, copulas are able to model better the empirically veri ed regularities normally attributed to multivariate nancial returns: (1) asymmetric conditional volatility with higher volatility for large negative returns and smaller volatility for positive returns (HAFNER, 1998); (2) conditional skewness (AITSAHALIA; BRANDT, 2001; CHEN; HONG; STEIN, 2001; PATTON, 2001); (3) excess kurtosis (TAUCHEN, 2001; ANDREOU; PITTIS; SPANOS, 2001); and (4) nonlinear temporal dependence (CONT, 2001; CAMPBELL; LO; MACKINLAY, 1997). The principal contribution of the essays is to assess if more sophisticated approaches than the distance method and plain Markowitz model can take advantage of any market anomalies/ fricctions. The essays are one attempt to provide a proper analysis in these issues using a long-term and comprehensive datasets. We empirically show that copula-based approaches are useful in all essays, proving bene cial to model dependencies in di erent scenarios, assessing the downside risk measures more adequately and yielding higher profitability than the benchmarks.

Qu’il s’agisse de prévenir sa survenance, d’empêcher qu’il s’aggrave ou de le réparer, le dommage est omniprésent dans l’arbitrage d’investissement. Il est à l’origine de la procédure contentieuse et de l’utilisation de divers mécanismes incidents. L’investisseur étranger dépose une requête d’arbitrage à l’encontre de l’État d’accueil, ou demande au tribunal saisi l’indication de mesures conservatoires, parce qu’il a subi, ou pourrait subir, un dommage. Le dommage (ré)apparaît également tout au long du déroulement de l’instance. Au stade de la compétence, il encadre l’intérêt pour agir de l’investisseur. Au fond, il apparaît comme un élément établissant l’existence de la violation des règles primaires. Le dommage constitue en outre, de façon plus classique, la mesure de la réparation. Il se manifeste, enfin, dans la finalité de l’arbitrage. L’investisseur entend obtenir l’indemnisation des dommages entretenant un rapport de causalité avec l’acte illicite. La présentation pourtant habituellement faite de ce contentieux l’exclut quasi systématiquement, si ce n’est au moment de la réparation. Les raisons de ce rejet se comprennent aisément si le dommage est uniquement analysé à la lumière de la position de la Commission du droit international, qui ne l’envisage que sous l’angle de son lien avec la responsabilité de l’État. Mais, à mieux y regarder, il ne se justifie plus si le dommage est replacé dans le contexte particulier du contentieux dans lequel il intervient. Il s’agira alors d’examiner le rôle du dommage, d’en caractériser et d’en expliquer la spécificité par rapport à celui qu’il occupe en droit international public et dans le contentieux interétatique, et de déterminer la mesure dans laquelle ce rôle spécifique influe sur la responsabilité de l’État d’accueil. / The harm is omnipresent in investment arbitration. It is at the origin of the proceedings and of the use of different incident mechanisms. A foreign investor files a request for arbitration against the host State, or asks for provisional measures, because it has or might have incurred damages due to the breach by the host State of its international obligations. The harm also (re)emerges all along the proceedings. At the jurisdiction stage, it determines the investor’s standing to act. At the merits stage, it is an element which establishes the violation of the applicable primary rules. Furthermore, the harm is, more classically, the measure of the reparation. Lastly, it reflects the purpose of arbitration. The investor requires compensation for losses which are causally linked to the breach. However, the presentation usually made of this dispute resolution mechanism almost systematically excludes it, except for issues concerning reparation. The reasons for this rejection can easily be understood if the harm is only analysed in the light of the International Law Commission’s position, which only considers the question from the perspective of its relation with State responsibility. But this rejection is no longer justified if the harm is replaced within the particular context in which it operates. Thus, this study will examine the role conferred to the harm in investment arbitration, characterise and explain its specificity compared with that it occupies in public international law and in inter-States disputes, and determine how and to what extent this specific role may affect State responsibility.

L’encadrement, par le droit international, du comportement de l’État hôte d’un investissement étranger n’est concevable que dans la mesure où sa souveraineté est limitée, l’enjeu étant la sanction de l’inobservation, par cet État, de ses obligations. Ces dernières sont issues de la pratique conventionnelle, surtout bilatérale, regroupant des traités qui disposent au fond. L’« internationalisation » du régime juridique de l’investissement n’est pas exclue comme mode de formation d’obligations mais ne se produit qu’à la faveur de dispositions dotées d’un tel effet. La pratique conventionnelle, assez uniforme, a comme principale caractéristique l’articulation de règles limitant le besoin d’interprétation autour de standards qui l’amplifient. Ceci, de même que les interprétations arbitrales, autorise à soupçonner une volonté de « remembrement » du standard minimum international. Si l’attribution d’un comportement à l’État d’accueil ne pose pas de difficulté inédite, l’établissement d’une violation, par cet État, de « ce qui est requis de lui » révèle des singularités de ce domaine. La qualification des circonstances excluant l’illicéité en situation d’urgence peut s’avérer problématique, le risque étant omniprésent d’une méconnaissance, de la part des arbitres, de la logique du droit de la responsabilité. En dehors de ces situations, on peut imaginer des hypothèses dans lesquelles l’illicéité est exclue suite au consentement de l’État d’origine ou de l’investisseur. Le préjudice subi par ce dernier, objet de la réparation intégrale due par l’État responsable, constitue le « préjudice causé par le fait internationalement illicite ». Il est immédiat et direct. L’investisseur, titulaire du droit d’invocation de la responsabilité de l’État hôte, a accès à une réclamation internationale qui éclipse celle de son État de nationalité. La perspective d’un endossement, par ce dernier, de la réclamation de son national accroît l’efficacité des traités d’investissement. / For the conduct of a foreign investment’s host State to be governed by international law is only conceivable insofar as its sovereignty is limited, since the issue is the sanction of the failure of that State to fulfill its obligations. The latter results from a mostly bilateral treaty practice embodying treaties which contain material provisions. The “internationalization” of the legal regime of an investment is not excluded as a means to create obligations, but only occurs through provisions with such an effect. The main characteristic to this fairly uniform treaty practice is the development of rules limiting the need for interpretation around a core set of standards amplifying it. This, as well as the arbitral interpretations, may reflect a desire to “consolidate” the international minimum standard. If the attribution of conduct to the host State does not raise any unprecedented issue, the establishment of a violation by that State of “what is required of it” reveals singularities in this field. The characterization of circumstances precluding wrongfulness in an emergency situation may prove problematic, as the risk that arbitrators may ignore the logic of the law of responsibility is omnipresent. Apart from these situations, it is possible to imagine hypotheses in which wrongfulness is precluded due to the consent of the State of origin or the investor. The injury sustained by the latter, which is the subject of full reparation due by the responsible State, constitutes “injury caused by the internationally wrongful act.” It is immediate and direct. The investor, entitled to invoke the responsibility of the host State, has access to an international claim which eclipses that of his State of nationality. The prospect of an espousal by the latter of its national’s claim increases the effectiveness of the investment treaties.

L'arbitrage d'investissement fondé sur des traités s'est fondamentalement construit autour de la protection de l'investisseur et de son investissement. En effet, les accords de protection de l'investissement n'imposent quasiment aucune obligation à la charge de l 'investisseur. De façon générale, ils contiennent des dispositions substantielles exigeant des États d'accueil d'accorder un certain traitement à l'investissement étranger. Du reste, l'arbitrage fondé sur des traités d'investissement constitue en lui-même une procédure unilatérale à la seule disposition de l'investisseur. La procédure est donc fondamentalement déséquilibrée. L'action des arbitres consistant à prendre en compte le comportement de l'investisseur a cependant contribué au rééquilibrage ce type d'arbitrage. Ils ont, en dépit des difficultés tant théoriques que pratiques suscitées par ce type de procédure, accompli leur mission en ayant recours à différents moyens tant procéduraux que matériels. Ce faisant, l'arbitre s'est rapproché de la figure du juge lié par un formalise certain lors de la conduite de sa procédure juridictionnelle. Par ailleurs, a pu être observée une certaine fonction normative indirecte de l'arbitre. Enfin, s'opère un processus de transition d'un contentieux exclusivement focalisé sur la responsabilité de l'État vers un contentieux de la responsabilisation de l'investisseur. / Investment treaty arbitration is fundamentally built around the protection of the investor and his/its investment. Indeed, investment protection agreements hardly impose any obligation on investors. Such agreements generally contain substantial provisions requiring that host States grant a certain treatment to foreign investments. Moreover, investment treaty arbitration is in itself a unilateral procedure available only to the investor. The procedure is thus fundamentally unbalanced. However, the taking into account by arbitrators of the behavior of investors, has helped to rebalance this investor-state arbitration. Despite theoretical as well as practical difficulties stemming from this type of procedure, arbitrators have been able to accomplish their mission by resorting to different methods, both procedural and material. In doing so, arbitrators have moved closer to the figure of judges, who are bound by some formalism when conducting judicial proceedings. Moreover, arbitral practice has shed the light on a certain indirect normative function of arbitrators. Lastly, a transition process is underway, from disputes exclusively focused on State responsibility towards an investor-accountability approach.