本文主要研究外匯市場在1983年11月到2014年10月期間是否存在動能效果(momentum effect)，並再更深入探討可能造成動能效果的原因。本文以美國投資者的角度，使用62個國家的貨幣，發現在使用較短期的遠期外匯及回顧較近期的歷史報酬作為判斷是否交易的依據，這樣的動能策略可以招致較高且較穩定成長的累積報酬；但是若使用較長天期遠期外匯及以較遠期的歷史報酬判斷，動能策略可能較不顯著，並且累積報酬也較不穩定，甚至在外幣國家發生突發性貨幣危機時，在外匯市場通常會發生反轉效果(reversal effect)。另外也驗證出動能策略的超額報酬很大部分是受到交易成本和即期匯率波動的影響。我們發現國家風險和動能效果平均而言呈現正向關係，流動性風險相較於國家風險對於動能效果的影響性較低。 / We investigate whether momentum effect exist or not in the foreign exchange market. We find, based on a sample of 62 market currencies and view U.S Dollar as based currency, the evidence of higher and more stable momentum excess returns as we apply the short formation and holding period in our momentum strategy portfolios. However, when we apply long formation and holding period in our momentum strategy portfolios, we find less momentum effect and unstable cumulative excess returns, and even in the crisis, we find reversal rather than momentum. Additionally, we provide the evidence that transaction cost and spot rate change is the dominant influence on momentum effect. The relationship between country risk and momentum effect is positive significance and liquidity risk provide less evidence on momentum effect.

Project finance is a financing arrangement for projects, and it is characterised by the creation of a legally independent project company financed with non- or limited recourse loans. It is observed that the popularity of project finance is increasing in the recent decades, despite of the impact of Asian financial crisis. Especially in emerging markets, project finance is very common among the public-private partnership projects. It is possible that project finance yields some benefits in project management that other forms of funding are not able to provide. This research aims to explore the impacts of project finance on the risk management of projects, as well as the mechanisms of the effects of various factors on project risk management. The research starts with a quantitative analysis which consists of project data from 32 projects in recent years. The regression analysis on these quantitative data reveals that factors such as the separation of legal entity and existence of third-party guarantees can effectively reduce the borrowing rates of the projects. The borrowing rates, expressed in terms of credit spreads over LIBOR, are regarded as a proxy for the overall risk level of the projects. The qualitative section which involves five structured interviews further explores the relationships of the attributes of project finance on project risk management. The interviewees largely agrees on the effects of the separation of legal entity, non- or limited recourse loans, and the existence of third-party guarantees in managing political and country risks, business risks, and principal-agency risks. The involvement of a larger number of stakeholders in the projects enable the project to enhance its risk management ability by gaining external expertise and knowledge, influences on government policies, and more importantly, closer supervisions on project activities. Apart from revealing the important features of project finance, and the potential benefits it may yield on project risk management, the effectiveness of these features are also discussed. The study also examines the relationships between these features and the common risk factors which may affect all projects. Some recommendations to enhance the benefits of project finance and reduce the associated transaction costs are made based on this study.

[pt] Nesse trabalho abordamos a importância do gerenciamento na sustentabilidade da dívida. Em um primeiro instante, definimos períodos de insustentabilidade da dívida pública de forma alternativa à literatura corrente. Através de modelos probabilísticos com variável dependente insustentabilidade sendo binária, encontramos evidências empíricas de que a composição e a duração da dívida influenciam a probabilidade de ocorrência de períodos de insustentabilidade, para o período compreendido entre janeiro de 1996 e setembro de 2005. Em um segundo momento, utilizamos a abordagem de gerenciamento de risco para analisar a sustentabilidade da dívida. Agregamos a essa abordagem o fato de decompormos a dívida pública por indexador. Através de simulações de Bootstrap em bloco e Monte Carlo, obtemos trajetórias explosivas da dívida pública, embora na ausência de risco, haja sustentabilidade. Além do mais, estimamos estatísticas de risco para a dívida e encontramos razoável correlação entre essas e o risco-país. Por fim, observamos que títulos indexados à taxa de juros selic e a moeda estrangeira aumentam a probabilidade de haver insustentabilidade. / [en] We discuss the importance of the debt management in its sustainability. At first, we define unsustainability periods of the public debt in an alternative way, if compared to the current literature. Using probabilistic models with unsustainability dependent dummy variable, we find empiric evidences that composition and duration of the debt influence the probability that unsustainability periods might occur, for the period between January 1996 and September 2005. In a second step, we use the risk management approach to analyze the debt sustainability. We include in this approach an analysis of the decomposition of the public debt. Applying Bootstrap and Monte Carlo simulations, we obtain some explosive trajectories of the public debt, although in the lack of risk, there is sustainability. In addition, we estimate risk statistics of the debt and we find reasonable correlation between these and the country risk. Finally, we observe that Selic interest rate and foreign currency indexed bonds raise the probability of unsustainability.

Nesta tese são desenvolvidos três estudos sobre as reservas internacionais brasileiras, utilizando diferentes técnicas econométricas, com o objetivo de determinar a influência de medidas absolutas e relativas de reservas sobre o rating soberano de crédito e o spread soberano, bem como o nível adequado para garantir a liquidez externa. As análises foram feitas com dados mensais do período jan/2000-jun/2008. No primeiro estudo, mostrou-se que diferentes medidas de reservas internacionais apresentam efeito significativo na explicação do rating soberano de crédito, através de modelos ordered logit para a média dos ratings emitidos pelas três principais agências (Moody's, Standard & Poors e Fitch). Entretanto, o indicador de maior poder explicativo não foi o nível absoluto de reservas, mas a razão entre dívida pública externa líquida e PIB. Outras variáveis de destacada importância na maioria dos modelos foram o percentual da dívida interna de curto prazo, investimento estrangeiro direto/PIB e inflação. Variáveis tradicionalmente utilizadas como indicadores de liquidez, como razão reservas/importações e conta corrente/PIB, não foram significativas na maioria dos modelos. Os resultados confirmam os indícios contidos no discurso das agências de rating, quanto à importância das reservas internacionais em sua avaliação, embora alertando que outras variáveis, como perfil de endividamento do governo e perspectivas de crescimento, são também fundamentais. O segundo estudo de caso encontrou relação significativa entre as reservas internacionais e o spread soberano, através de modelos de correção de erros. O efeito estimado do rating soberano foi não-significativo ou pouco explicativo, comparado aos fundamentos, provavelmente devido à volatilidade do spread soberano em resposta a variações nas condições do mercado, ao contrário do rating. O melhor modelo obtido utilizou o nível absoluto de reservas, evidenciando também efeitos significativos da aversão global ao risco, taxas de juros internacionais e crises políticas internas. Os resultados desse estudo indicam custo marginal decrescente das reservas internacionais e a necessidade de considerá-lo endógeno em modelos de minimização de custos para determinação do nível ótimo de reservas. O terceiro estudo implementou a metodologia de Liquidity-at-Risk sugerida por Greenspan (1999) para avaliar a adequação do nível de reservas internacionais para a manutenção da liquidez externa. Para a medida de liquidez reservas/dívida externa de curto prazo (razão de Guidotti), estimou-se que o nível de reservas internacionais mantidas pelo Brasil em jun/2008 (US$200 bilhões) era aproximadamente o dobro do necessário para garantir uma razão de Guidotti superior a 1, com 99% de probabilidade, durante 24, 36 ou 48 meses. Em diversos cenários alternativos de percentual das dívidas externa e interna de curto prazo, meta de superávit primário, índice de aversão ao risco e taxas de juros externas, as reservas iniciais necessárias situaram-se em US$85-105 bilhões. A análise de custos revela que o aumento das reservas diminui os juros médios da dívida, embora efeito maior pudesse ser alcançado através do aumento do superávit primário. As evidências sugerem que a motivação das autoridades brasileiras para a manutenção de reservas em torno de US$200 bilhões não é puramente precaucionária, admitindo as hipóteses de ganho de credibilidade e flexibilidade para a execução da política fiscal. / This thesis developed three case studies on the Brazilian international reserves, using various econometric techniques in order to determine the influence of absolute and relative measures of reserves over both the sovereign credit rating and the sovereign spread, as well as to assess the adequate reserves level to ensure external liquidity. Analyses were carried out on monthly data from Jan/2000 to Jun/2008. The first case study found significant effects of different reserves measures in explaining the sovereign credit rating, by fitting ordered logit models to the average of the ratings issued by the three main agencies (Moody's, Standard & Poors and Fitch) for the Brazilian long term external debt. However, the best explaining variable was not the absolute level of reserves, but the ratio "net public external debt/GDP" instead. It was noteworthy the significance of the following variables in most of the models tested: short term internal debt (%), foreign direct investment/GDP and inflation. Variables traditionally used as external liquidity measures, like reserves/imports and current account/GDP, are not statistically significant in most of the models fitted in this study. Results support the evidence found in the rating agencies' reports, as to the importance of international reserves in their credit quality assessment, although pointing to other variables, like government debt profile and growth perspectives, as equally critical. The second case study found significant relationship between the Brazilian international reserves and its sovereign spread, using error correction models. The estimated effect of sovereign rating was either non-significant, or poorly explanatory when compared to macroeconomic fundamentals, probably due to the volatility of sovereign spread in response to changes in market conditions, unlike the sovereign rating. The best model obtained included the absolute level of reserves, showing also significant effect of the global risk aversion, external interest rates and internal political crises. The results of this study point to a decreasing marginal cost of international reserves and the need of considering it as endogenous in optimal reserves models based in cost minimization. Finally, the third case study implemented the Liquidity-at-Risk methodology suggested by Greenspan (1999), in order to assess the Brazilian reserves level adequacy in maintaining external liquidity. For the liquidity measure adopted - the ratio "reserves/short term external debt" (Guidotti's ratio) - it was found that the Brazilian reserves level held in Jun/2008 (US$200 billion) was roughly twice the necessary one to ensure a Guidotti's ratio above 1, with 99% probability, within 24, 36 or 48 months. In several alternative scenarios varying the short term external debt, short term internal debt, primary surplus, global risk aversion and external interest rates, the required initial reserves was in the range US$85-105 billion. An analysis of alternative policies' costs revealed the expected effect of higher reserves in decreasing the average debt service, although a dramatically higher impact would be obtained by an increase in primary surplus. Evidence suggest that the Brazilian authorities motivation for holding international reserves as high as US$200 billion may not be purely precautionary, pointing to the hypotheses of credibility gains and fiscal flexibility issues.

Submitted by Luiz Felipe Poli Guanais (fguanais@hotmail.com) on 2014-12-04T21:20:32Z No. of bitstreams: 1 Dissertação - Luiz Felipe Poli Guanais.pdf: 620638 bytes, checksum: 02d37cff8a2c05c0d78f721b513a6b18 (MD5) / Rejected by JOANA MARTORINI (joana.martorini@fgv.br), reason: Luiz, bom dia. Seu trabalho não está de acordo com as regras. Por gentileza entrar em contato no telefone 3799-7892. on 2014-12-05T11:28:59Z (GMT) / Submitted by Luiz Felipe Poli Guanais (fguanais@hotmail.com) on 2014-12-08T18:14:11Z No. of bitstreams: 1 Dissertação - Luiz Felipe Poli Guanais.pdf: 938612 bytes, checksum: 5e47fb061492e1f2070ebe6b698fa28f (MD5) / Approved for entry into archive by JOANA MARTORINI (joana.martorini@fgv.br) on 2014-12-08T19:02:27Z (GMT) No. of bitstreams: 1 Dissertação - Luiz Felipe Poli Guanais.pdf: 938612 bytes, checksum: 5e47fb061492e1f2070ebe6b698fa28f (MD5) / Made available in DSpace on 2014-12-08T19:03:48Z (GMT). No. of bitstreams: 1 Dissertação - Luiz Felipe Poli Guanais.pdf: 938612 bytes, checksum: 5e47fb061492e1f2070ebe6b698fa28f (MD5) Previous issue date: 2014-11-25 / O objetivo do presente trabalho foi, face ao grau de integração da economia brasileira, testar o poder explicativo do Modelo Goldman Sachs sobre os retornos esperados por um investidor estrangeiro no mercado nacional, ao longo do período 2004-2013. Em um primeiro momento, foi testado o grau de integração da economia brasileira para o período 2004-2013, buscando entender o contexto em que o Modelo Goldman Sachs foi empregado. Posteriormente, para o teste do modelo, calcularam-se os betas dos fatores de risco dos ativos analisados (risco de mercado e risco país) e procedeu-se à regressão com dados em painel dos retornos esperados sobre os betas desses ativos. Verificou-se que o risco país não se mostrou estatisticamente significante para a explicação dos retornos esperados, o que indica que é adicionado de maneira ad hoc pelos praticantes de mercado para o cálculo do custo de capital próprio de acordo com o Modelo Goldman Sachs. Assim, embora haja evidências de uma relação positiva e significante entre risco sistemático e retorno, os resultados para o risco país demonstram que o Modelo Goldman Sachs não se mostrou satisfatório para a explicação dos retornos esperados no mercado brasileiro ao longo dos últimos dez anos. / Considering the degree of integration of the Brazilian economy, this paper seeks to test the explanatory power of the Goldman Sachs Model for the expected returns by a foreign investor in the Brazilian market during the past ten years (2004-2013). It begins by testing the degree of integration of the Brazilian economy during this period, in an attempt to better understand the context in which the model has been used. In sequence, the risk factor betas (market risk and country risk) of the sample stocks were estimated and a panel regression of expected stock returns on these betas was performed. It was found that country risk is not a statistically significant explanation of expected returns, indicating that it has been added in an ad hoc fashion by market practitioners to cost of equity calculations. Thus, although there is evidence of a positive and significant relationship between systematic risk and return, the results for country risk demonstrate that the Goldman Sachs Model was not a satisfactory explanation of expected returns in the Brazilian market in the past ten years.

Submitted by Márcio Martins Bonilha Neto (marciombneto@gmail.com) on 2016-03-08T00:56:19Z No. of bitstreams: 1 Aspectos Institucionais do Risco País.pdf: 896188 bytes, checksum: 08b8748e7bceb5984bd2d264be2d3c02 (MD5) / Rejected by Renata de Souza Nascimento (renata.souza@fgv.br), reason: Marcio, boa tarde Por gentileza, alterar SÃO PAULO 2015 para SÃO PAULO 2016, devido à data de sua apresentação. Após alteração, realizar uma nova submissão. Att on 2016-03-08T17:10:39Z (GMT) / Submitted by Márcio Martins Bonilha Neto (marciombneto@gmail.com) on 2016-03-10T01:08:41Z No. of bitstreams: 1 Dissertação Márcio.pdf: 893573 bytes, checksum: 6d4dc46af4ab85a1fe8353677f8b5f7c (MD5) / Approved for entry into archive by Renata de Souza Nascimento (renata.souza@fgv.br) on 2016-03-10T16:27:09Z (GMT) No. of bitstreams: 1 Dissertação Márcio.pdf: 893573 bytes, checksum: 6d4dc46af4ab85a1fe8353677f8b5f7c (MD5) / Made available in DSpace on 2016-03-10T16:46:25Z (GMT). No. of bitstreams: 1 Dissertação Márcio.pdf: 893573 bytes, checksum: 6d4dc46af4ab85a1fe8353677f8b5f7c (MD5) Previous issue date: 2016-02-15 / The measurement of country risk is of utmost importance at a time of frequent international portfolio diversification. This paper aims to understand which variables are important in these metrics, with a main focus among institutional aspects. To accomplish this purpose, it analyzes the Credit Default Swap (CDS) and the Emerging Markets Bond Index (EMBI), which not only measure the risk of countries, but also are also financial products, bought and sold by hedgers and speculators. Their prices are therefore formed by the market. The intent here is to analyze whether the institutional aspects of the countries, as well as their changes, are important in defining this risk, without forgetting, of course, the economic variables of each country. By institutional aspects, we understand the structure of the state, such as democracy and corruption in each country, press freedom, the socioeconomic status of the population, the fact that the country has a parliamentary regime, the influences the legal system, among other variables. / A mensuração do risco país é de extrema importância em um momento de frequente diversificação internacional do portfólio. O presente trabalho pretende entender quais as variáveis são importantes nessas métricas, com um foco principal entre os aspectos institucionais. Para isso, são analisados o Credit Default Swap (CDS) e o Emerging Markets Bond Index (EMBI), que além de medirem o risco dos países, são também produtos financeiros, comprados e vendidos por hedgers e especuladores. Seus preços são, portanto, formados pelo mercado. A intenção aqui é analisar se os aspectos institucionais dos países, bem como suas alterações, são importantes na definição deste risco, sem esquecer, obviamente, das variáveis econômicas de cada país. Por aspectos institucionais, entendemos a estrutura do Estado, como é a democracia e a corrupção em cada país, a liberdade de imprensa, o nível socioeconômico da população, o fato de o país é parlamentarista, as influências do sistema jurídico, entre outras variáveis.

Submitted by João Guilherme Santos Lazzaro (jgslazzaro@gmail.com) on 2017-06-01T19:42:19Z No. of bitstreams: 1 Dissertacao_Joao_Lazzaro.pdf: 438996 bytes, checksum: fa5de7c51b56f54e091b16462c9082ac (MD5) / Rejected by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br), reason: Boa tarde João Guilherme, Por favor, Nome da Fundação e Escola na cada, contra-cara tirar nome da fundação e escola, as palavras agradecimento, Abstract e resumo em caixa alta. Caso tenha dúvida verifique um trabalho de colega na biblioteca digital por favor. Grata. Suzi 3799-7876 on 2017-06-02T19:02:46Z (GMT) / Submitted by João Guilherme Santos Lazzaro (jgslazzaro@gmail.com) on 2017-06-05T13:07:03Z No. of bitstreams: 1 Dissertacao_ABNT.pdf: 439884 bytes, checksum: 2d9b6e834e25280ffe61b3eb1a936012 (MD5) / Approved for entry into archive by Suzinei Teles Garcia Garcia (suzinei.garcia@fgv.br) on 2017-06-05T13:31:02Z (GMT) No. of bitstreams: 1 Dissertacao_ABNT.pdf: 439884 bytes, checksum: 2d9b6e834e25280ffe61b3eb1a936012 (MD5) / Made available in DSpace on 2017-06-05T20:35:34Z (GMT). No. of bitstreams: 1 Dissertacao_ABNT.pdf: 439884 bytes, checksum: 2d9b6e834e25280ffe61b3eb1a936012 (MD5) Previous issue date: 2017-05-12 / Country risk is known to be an important driver of emerging economies business cycles. Existing studies of macroeconomics effects of commodities prices on emerging economies' country risk assume an exogenous negative relation between these two variables. This work presents a model to explain endogenously this relation built upon the sovereign debt literature deriving from Arellano (2008). Our framework is then used to assess quantitatively the importance of the country risk effect of commodity prices on output volatility. We find that although this effect is negligible for economies with a high share of commodities on GDP but low indebtedness, the effect is important in indebted economies with a lower share of commodities in GDP. / O risco país é conhecido por ser um motor importante dos ciclos econômicos das economias emergentes. Os estudos existentes sobre os efeitos macroeconômicos dos preços das commodities sobre o risco país das economias emergentes assumem uma relação negativa exógena entre essas duas variáveis. Este trabalho apresenta um modelo para explicar endogenamente esta relação baseado na literatura de dívida soberana derivada de Arellano (2008). Este arcabouço é então utilizado para avaliar quantitativamente a importância efeito do risco país dos preços de commodities sobre a volatilidade do produto. Descobre-se que, embora este efeito seja insignificante para economias com uma alta proporção de commodities em relação ao PIB e baixo endividamento, o efeito é importante em economias endividadas com menor participação de commodities no PIB.

Nesta tese são desenvolvidos três estudos sobre as reservas internacionais brasileiras, utilizando diferentes técnicas econométricas, com o objetivo de determinar a influência de medidas absolutas e relativas de reservas sobre o rating soberano de crédito e o spread soberano, bem como o nível adequado para garantir a liquidez externa. As análises foram feitas com dados mensais do período jan/2000-jun/2008. No primeiro estudo, mostrou-se que diferentes medidas de reservas internacionais apresentam efeito significativo na explicação do rating soberano de crédito, através de modelos ordered logit para a média dos ratings emitidos pelas três principais agências (Moody's, Standard & Poors e Fitch). Entretanto, o indicador de maior poder explicativo não foi o nível absoluto de reservas, mas a razão entre dívida pública externa líquida e PIB. Outras variáveis de destacada importância na maioria dos modelos foram o percentual da dívida interna de curto prazo, investimento estrangeiro direto/PIB e inflação. Variáveis tradicionalmente utilizadas como indicadores de liquidez, como razão reservas/importações e conta corrente/PIB, não foram significativas na maioria dos modelos. Os resultados confirmam os indícios contidos no discurso das agências de rating, quanto à importância das reservas internacionais em sua avaliação, embora alertando que outras variáveis, como perfil de endividamento do governo e perspectivas de crescimento, são também fundamentais. O segundo estudo de caso encontrou relação significativa entre as reservas internacionais e o spread soberano, através de modelos de correção de erros. O efeito estimado do rating soberano foi não-significativo ou pouco explicativo, comparado aos fundamentos, provavelmente devido à volatilidade do spread soberano em resposta a variações nas condições do mercado, ao contrário do rating. O melhor modelo obtido utilizou o nível absoluto de reservas, evidenciando também efeitos significativos da aversão global ao risco, taxas de juros internacionais e crises políticas internas. Os resultados desse estudo indicam custo marginal decrescente das reservas internacionais e a necessidade de considerá-lo endógeno em modelos de minimização de custos para determinação do nível ótimo de reservas. O terceiro estudo implementou a metodologia de Liquidity-at-Risk sugerida por Greenspan (1999) para avaliar a adequação do nível de reservas internacionais para a manutenção da liquidez externa. Para a medida de liquidez reservas/dívida externa de curto prazo (razão de Guidotti), estimou-se que o nível de reservas internacionais mantidas pelo Brasil em jun/2008 (US$200 bilhões) era aproximadamente o dobro do necessário para garantir uma razão de Guidotti superior a 1, com 99% de probabilidade, durante 24, 36 ou 48 meses. Em diversos cenários alternativos de percentual das dívidas externa e interna de curto prazo, meta de superávit primário, índice de aversão ao risco e taxas de juros externas, as reservas iniciais necessárias situaram-se em US$85-105 bilhões. A análise de custos revela que o aumento das reservas diminui os juros médios da dívida, embora efeito maior pudesse ser alcançado através do aumento do superávit primário. As evidências sugerem que a motivação das autoridades brasileiras para a manutenção de reservas em torno de US$200 bilhões não é puramente precaucionária, admitindo as hipóteses de ganho de credibilidade e flexibilidade para a execução da política fiscal. / This thesis developed three case studies on the Brazilian international reserves, using various econometric techniques in order to determine the influence of absolute and relative measures of reserves over both the sovereign credit rating and the sovereign spread, as well as to assess the adequate reserves level to ensure external liquidity. Analyses were carried out on monthly data from Jan/2000 to Jun/2008. The first case study found significant effects of different reserves measures in explaining the sovereign credit rating, by fitting ordered logit models to the average of the ratings issued by the three main agencies (Moody's, Standard & Poors and Fitch) for the Brazilian long term external debt. However, the best explaining variable was not the absolute level of reserves, but the ratio "net public external debt/GDP" instead. It was noteworthy the significance of the following variables in most of the models tested: short term internal debt (%), foreign direct investment/GDP and inflation. Variables traditionally used as external liquidity measures, like reserves/imports and current account/GDP, are not statistically significant in most of the models fitted in this study. Results support the evidence found in the rating agencies' reports, as to the importance of international reserves in their credit quality assessment, although pointing to other variables, like government debt profile and growth perspectives, as equally critical. The second case study found significant relationship between the Brazilian international reserves and its sovereign spread, using error correction models. The estimated effect of sovereign rating was either non-significant, or poorly explanatory when compared to macroeconomic fundamentals, probably due to the volatility of sovereign spread in response to changes in market conditions, unlike the sovereign rating. The best model obtained included the absolute level of reserves, showing also significant effect of the global risk aversion, external interest rates and internal political crises. The results of this study point to a decreasing marginal cost of international reserves and the need of considering it as endogenous in optimal reserves models based in cost minimization. Finally, the third case study implemented the Liquidity-at-Risk methodology suggested by Greenspan (1999), in order to assess the Brazilian reserves level adequacy in maintaining external liquidity. For the liquidity measure adopted - the ratio "reserves/short term external debt" (Guidotti's ratio) - it was found that the Brazilian reserves level held in Jun/2008 (US$200 billion) was roughly twice the necessary one to ensure a Guidotti's ratio above 1, with 99% probability, within 24, 36 or 48 months. In several alternative scenarios varying the short term external debt, short term internal debt, primary surplus, global risk aversion and external interest rates, the required initial reserves was in the range US$85-105 billion. An analysis of alternative policies' costs revealed the expected effect of higher reserves in decreasing the average debt service, although a dramatically higher impact would be obtained by an increase in primary surplus. Evidence suggest that the Brazilian authorities motivation for holding international reserves as high as US$200 billion may not be purely precautionary, pointing to the hypotheses of credibility gains and fiscal flexibility issues.

La chute récente du prix des matières premières a montré la vulnérabilité que pouvait impliquer une trop forte dépendance des économies aux revenus provenant des ressources naturelles. Dans le premier chapitre, les résultats que nous obtenons indiquent que les prix des matières premières sont un indicateur important du risque pays des exportateurs, ce qui n’est pas le cas des pays qui sont importateurs. Bien que les pays exportateurs soient aujourd’hui ceux dont le défaut externe est le plus probable, il n’apparaît pas de prime de risque supplémentaire liée à la détention de leurs obligations. Dans le deuxième chapitre, nous étudions le lien entre les termes de l’échange et le taux de change effectif réel entre et de exportateurs de matières premières . Il existe une relation de long terme entre les termes de l’échange des pays exportateurs et leur taux de change réel. Les termes de l’échange n’ont pas d’impact à court-terme sur les taux de change effectifs réels. Néanmoins, nous montrons grâce à l’estimation d’un modèle à seuil à transition lisse en panel PSTR , qu’ une forte baisse du prix du pétrole (entre 25% et 36%) donnent un pouvoir explicatif aux termes de l’échange. Même si la question est encore largement débattue dans la littérature, l’idée qu’il existe une "malédiction des ressources naturelles" a fait sa place. Les pays fortement dotés en ressources naturelles auraient en moyenne une croissance économique plus faible que ceux qui n’en sont pas pourvus. Dans le dernier chapitre, nous proposons une méta-analyse basée sur un échantillon de 67 études empiriques qui étudient le lien entre ressources naturelles et croissance économique. Sur la base d’un ensemble de coefficients estimés, nos résultats montrent qu’il existe une "faible" malédiction des ressources. / The recent drop in commodity prices showed the high vulnerability implied by being too much dependent on revenues stemming from natural resources. In the first chapter, we look into the way financial markets assess the market risk of twenty-two emerging economies. More precisely, the purpose of this chapter is to investigate how natural resources are incorporated in the way international investors perceived the ability to service external debt obligationsduring the 2003-2014 period. The results indicate that commodity prices are an important driver of sovereign spreads in the case of exporters while it is not the case for importing countries. In the second chapter, we investigate the link between energy prices and the real effective exchange rate of commodity-exporting countries. Estimating a panel cointegration relation between the real effective exchange rate and its fundamentals, we provide evidence for the existence of both energy and commodity currencies and we show that when the oil market is highly volatile (downwards), currencies follow an "oil currency regime", terms-of trade becoming an important driver of the real exchange rate A conventional wisdom has spread in the literature stating that a high endowment in natural resources is detrimental for growth, yet the debate is still ongoing In this chapter, we aim at providing quantitative results on the magnitude of the link between natural resources and growth found in the literature, as well as discussing, on quantitative bases, whether the sources of heterogeneity are significant. To this end, we implement a meta-analysis based on 67 empirical studies that investigate the link between natural resources and growth, totaling 1405 estimates. The results show a "soft" curse that may be reverted together with the importance of institutions in mitigating the curse.

Nesta tese são desenvolvidos três estudos sobre as reservas internacionais brasileiras, utilizando diferentes técnicas econométricas, com o objetivo de determinar a influência de medidas absolutas e relativas de reservas sobre o rating soberano de crédito e o spread soberano, bem como o nível adequado para garantir a liquidez externa. As análises foram feitas com dados mensais do período jan/2000-jun/2008. No primeiro estudo, mostrou-se que diferentes medidas de reservas internacionais apresentam efeito significativo na explicação do rating soberano de crédito, através de modelos ordered logit para a média dos ratings emitidos pelas três principais agências (Moody's, Standard & Poors e Fitch). Entretanto, o indicador de maior poder explicativo não foi o nível absoluto de reservas, mas a razão entre dívida pública externa líquida e PIB. Outras variáveis de destacada importância na maioria dos modelos foram o percentual da dívida interna de curto prazo, investimento estrangeiro direto/PIB e inflação. Variáveis tradicionalmente utilizadas como indicadores de liquidez, como razão reservas/importações e conta corrente/PIB, não foram significativas na maioria dos modelos. Os resultados confirmam os indícios contidos no discurso das agências de rating, quanto à importância das reservas internacionais em sua avaliação, embora alertando que outras variáveis, como perfil de endividamento do governo e perspectivas de crescimento, são também fundamentais. O segundo estudo de caso encontrou relação significativa entre as reservas internacionais e o spread soberano, através de modelos de correção de erros. O efeito estimado do rating soberano foi não-significativo ou pouco explicativo, comparado aos fundamentos, provavelmente devido à volatilidade do spread soberano em resposta a variações nas condições do mercado, ao contrário do rating. O melhor modelo obtido utilizou o nível absoluto de reservas, evidenciando também efeitos significativos da aversão global ao risco, taxas de juros internacionais e crises políticas internas. Os resultados desse estudo indicam custo marginal decrescente das reservas internacionais e a necessidade de considerá-lo endógeno em modelos de minimização de custos para determinação do nível ótimo de reservas. O terceiro estudo implementou a metodologia de Liquidity-at-Risk sugerida por Greenspan (1999) para avaliar a adequação do nível de reservas internacionais para a manutenção da liquidez externa. Para a medida de liquidez reservas/dívida externa de curto prazo (razão de Guidotti), estimou-se que o nível de reservas internacionais mantidas pelo Brasil em jun/2008 (US$200 bilhões) era aproximadamente o dobro do necessário para garantir uma razão de Guidotti superior a 1, com 99% de probabilidade, durante 24, 36 ou 48 meses. Em diversos cenários alternativos de percentual das dívidas externa e interna de curto prazo, meta de superávit primário, índice de aversão ao risco e taxas de juros externas, as reservas iniciais necessárias situaram-se em US$85-105 bilhões. A análise de custos revela que o aumento das reservas diminui os juros médios da dívida, embora efeito maior pudesse ser alcançado através do aumento do superávit primário. As evidências sugerem que a motivação das autoridades brasileiras para a manutenção de reservas em torno de US$200 bilhões não é puramente precaucionária, admitindo as hipóteses de ganho de credibilidade e flexibilidade para a execução da política fiscal. / This thesis developed three case studies on the Brazilian international reserves, using various econometric techniques in order to determine the influence of absolute and relative measures of reserves over both the sovereign credit rating and the sovereign spread, as well as to assess the adequate reserves level to ensure external liquidity. Analyses were carried out on monthly data from Jan/2000 to Jun/2008. The first case study found significant effects of different reserves measures in explaining the sovereign credit rating, by fitting ordered logit models to the average of the ratings issued by the three main agencies (Moody's, Standard & Poors and Fitch) for the Brazilian long term external debt. However, the best explaining variable was not the absolute level of reserves, but the ratio "net public external debt/GDP" instead. It was noteworthy the significance of the following variables in most of the models tested: short term internal debt (%), foreign direct investment/GDP and inflation. Variables traditionally used as external liquidity measures, like reserves/imports and current account/GDP, are not statistically significant in most of the models fitted in this study. Results support the evidence found in the rating agencies' reports, as to the importance of international reserves in their credit quality assessment, although pointing to other variables, like government debt profile and growth perspectives, as equally critical. The second case study found significant relationship between the Brazilian international reserves and its sovereign spread, using error correction models. The estimated effect of sovereign rating was either non-significant, or poorly explanatory when compared to macroeconomic fundamentals, probably due to the volatility of sovereign spread in response to changes in market conditions, unlike the sovereign rating. The best model obtained included the absolute level of reserves, showing also significant effect of the global risk aversion, external interest rates and internal political crises. The results of this study point to a decreasing marginal cost of international reserves and the need of considering it as endogenous in optimal reserves models based in cost minimization. Finally, the third case study implemented the Liquidity-at-Risk methodology suggested by Greenspan (1999), in order to assess the Brazilian reserves level adequacy in maintaining external liquidity. For the liquidity measure adopted - the ratio "reserves/short term external debt" (Guidotti's ratio) - it was found that the Brazilian reserves level held in Jun/2008 (US$200 billion) was roughly twice the necessary one to ensure a Guidotti's ratio above 1, with 99% probability, within 24, 36 or 48 months. In several alternative scenarios varying the short term external debt, short term internal debt, primary surplus, global risk aversion and external interest rates, the required initial reserves was in the range US$85-105 billion. An analysis of alternative policies' costs revealed the expected effect of higher reserves in decreasing the average debt service, although a dramatically higher impact would be obtained by an increase in primary surplus. Evidence suggest that the Brazilian authorities motivation for holding international reserves as high as US$200 billion may not be purely precautionary, pointing to the hypotheses of credibility gains and fiscal flexibility issues.