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.

華人社會傳承了儒家文化思想的價值觀，但是在社會環境、政治體制及人口結構等因素的差異之下，衍生出各種文化特性的差異。本研究使用世界價值觀調查（World Values Survey，WVS）資料，比較不同社會中的華人在文化特性方面的差異，並分析文化特性及其他因素對主觀福祉（subjective well-being）的影響。 本研究採用世界價值觀調查所建立之社會價值觀（societal values），加入其他文化特徵、社會態度及個人生活觀衡量文化特性。本研究使用之計量模型為排序羅吉特迴歸（ordered logit regression）模型，分析上述變數對華人生活滿意度（life satisfaction）與快樂程度（happiness）的影響。本研究之目的在於找出影響華人主觀福祉之重要決定因素，並探討文化因素在收入與主觀福祉之間是否存在調節效果（moderating effect）。 實證結果顯示，文化會影響華人主觀福祉，並在收入與主觀福祉之間造成調節效果。而華人在各個社會中所衍生出的文化特性差異，也使得各個社會中華人主觀福祉的重要決定因素有所差異。 / Chinese societies inherited the values of Confucianism. However, these societies vary in their social environment, political system and demographic structure, thus result in differences in their cultural characteristics. This study uses the data from World Values Survey, to explore the differences among Chinese in different societies, and to analyze the determining factors of Chinese subjective well-being. In this study, the societal values established by the World Values Survey are used to represent the cultural properties. We also added other cultural traits, social attitudes and individual viewpoints for our analysis. In this study, we use ordered logit regression model to find out the important determinants of Chinese subjective well-being in different societies, and discuss whether there exists a cultural moderating effect between income and subjective well-being. Empirical results show that culture has a significant impact on subjective well-being of Chinese, and the effect of income on Chinese subjective well-being are also moderated by cultural properties. The differences between these Chinese societies also result in divergences of important determinants of Chinese subjective well-being between societies.

Este trabalho apresenta três extensões ao modelo de reputação proposto por Shapiro (1983). A primeira torna o modelo original mais adequado para avaliar o problema de informação assimétrica de bens de busca e bens credenciais, a segunda permite identificar o ganho de eficiência gerado pela inclusão de um sistema de informação adicional e, a terceira mostra que a provisão de um volume maior de informação pode gerar efeitos adversos quando o produto em questão possui vários atributos. Em seguida, os desenvolvimentos teóricos são utilizados para avaliar os efeitos da introdução do Exame Nacional de Cursos sobre o mercado de cursos superiores do Brasil. Algumas das predições do modelo são testadas empiricamente, fornecendo indicações de que este Exame possui um papel relevante para mitigar o problema de informação identificado neste mercado. / This essay presents three extensions to the model first proposed by Shapiro (1983) regarding reputation. The first extension adjusts Shapiro’s original model in order to make it more suitable in dealing with the problem of asymmetric information of search goods and credence goods. The second one allows the identification of the efficiency gains obtained after the inclusion of an additional information system, while the third extension demonstrates that additional information could generate adverse effects when the good under consideration has several attributes. These theoretical extensions are then applied to evaluate the effects of the Brazilian experience regarding the introduction of the Courses National Exam - Exame Nacional de Cursos – on Brazil’s market of undergraduate school courses. Some of the theoretical predictions of the model are empirically tested, offering indications that such exam plays a relevant role while diminishing the informational problem that characterizes this market.

Este trabalho apresenta três extensões ao modelo de reputação proposto por Shapiro (1983). A primeira torna o modelo original mais adequado para avaliar o problema de informação assimétrica de bens de busca e bens credenciais, a segunda permite identificar o ganho de eficiência gerado pela inclusão de um sistema de informação adicional e, a terceira mostra que a provisão de um volume maior de informação pode gerar efeitos adversos quando o produto em questão possui vários atributos. Em seguida, os desenvolvimentos teóricos são utilizados para avaliar os efeitos da introdução do Exame Nacional de Cursos sobre o mercado de cursos superiores do Brasil. Algumas das predições do modelo são testadas empiricamente, fornecendo indicações de que este Exame possui um papel relevante para mitigar o problema de informação identificado neste mercado. / This essay presents three extensions to the model first proposed by Shapiro (1983) regarding reputation. The first extension adjusts Shapiro’s original model in order to make it more suitable in dealing with the problem of asymmetric information of search goods and credence goods. The second one allows the identification of the efficiency gains obtained after the inclusion of an additional information system, while the third extension demonstrates that additional information could generate adverse effects when the good under consideration has several attributes. These theoretical extensions are then applied to evaluate the effects of the Brazilian experience regarding the introduction of the Courses National Exam - Exame Nacional de Cursos – on Brazil’s market of undergraduate school courses. Some of the theoretical predictions of the model are empirically tested, offering indications that such exam plays a relevant role while diminishing the informational problem that characterizes this market.

This thesis consists of four self-contained essays on the various topics in finance.  The first essay, The Information Content of The Systematic Risk Structure of Corporate Yields for Future Real Activity: An Exploratory Empirical Investigation, constructs a proxy for the systematic component of the risk structure of corporate yields (or systematic risk structure), and tests how well it predicts real economic activity in the United States. It finds that the systematic risk structure predicts the growth rate of industrial production 3 to 18 months into the future even when other leading indicators are controlled for, outperforming other models. A regime-switching estimation also shows that the systematic risk structure is very successful in identifying and capturing different growth regimes of industrial production.  The second essay, How Much Leverage is Too Much, or Does Corporate Risk Determine the Severity of a Recession? investigates whether financial conditions of the U.S. corporate sector  can explain the probability and severity of recessions. It proposes a measure of corporate vulnerability, the Corporate Vulnerability Index (CVI) constructed as the default probability for the entire corporate sector. It finds that the CVI is a significant predictor of the probability of a recession 4 to 6 quarters ahead, even controlling for other leading indicators, and that an increase in the CVI is also associated with a rise in the probability of a more severe and lengthy recession 3 to 6 quarters ahead.  The third essay, Asian Flu or Wall Street Virus? Tech and Non-Tech Spillovers in the United States and Asia (with Jorge A. Chan-Lau), using TGARCH models, finds that U.S. stock markets have been the major source of price and volatility spillovers to stock markets in the Asia-Pacific region during three different periods: the pre-LTCM crisis period, the “tech bubble” period, and the “stock market correction” period. Hong Kong SAR, Japan, and Singapore were sources of spillovers within the region and affected the United States during the latter period. There is also evidence of structural breaks in the stock price and volatility dynamics induced during the “tech bubble” period.  The fourth essay, Coping with Financial Spillovers from the United States: The Effect of U. S. Corporate Scandals on Canadian Stock Prices, investigates the effect of U.S. corporate scandals on stock prices of Canadian firms interlisted  in the United States. It finds that firms interlisted during the pre-Enron period enjoyed increases in post-listing equilibrium prices, while firms interlisted during the post-Enron period experienced declines in post-listing equilibrium prices, relative to a model-based benchmark. Analyzing the entire universe of Canadian firms, it finds that interlisted firms, regardless of their listing time, were perceived as increasingly risky by Canadian investors after the Enron’s bankruptcy. / Diss. Stockholm : Handelshögskolan, 2003

Made available in DSpace on 2016-06-02T19:58:04Z (GMT). No. of bitstreams: 1 3674.pdf: 4771914 bytes, checksum: 5dd14583c2d833c9bb3c7f0ec784e9d4 (MD5) Previous issue date: 2011-02-21 / Universidade Federal de Minas Gerais / This research attempted to study the issue of assessing the level of service for bicycles in Brazilian cities, with the ultimate aim of developing a bicycle level of service model that can be used in medium-sized Brazilian cities. The methodology used for model development began with the identification of attributes that can be used to describe the level of service for bicycles, followed by assessing the perceptions of individuals about the importance of the attributes. Among the methods available to measure the perceptions of individuals about the roadway characteristics related to bicycle transportation, it was chosen to use simulations (video based evaluation). The video was produced through a system in which a portable video camera was attached to the bicycle stern. To compensate for the exclusion of some attributes that could not be assessed through video (such as the sensation of heat, the cost of the bicycle, the health benefits, etc) the simulation method was combined with another method of perception analysis: questionnaires formulated based on the Likert scale. Data collection was performed in a case study in the cities of São Carlos and Rio Claro (São Paulo state), in several educational facilities. In total, 451 questionnaires were administered, 60 in the city of Rio Claro and the rest of them in the city of São Carlos. The results of field study were analyzed through methods of descriptive statistics and correlations, producing the following studies: questionnaires results, classification of participants into types of cyclists, the definition of a scale of acceptability to bicycle use and classification of participants in groups, according to this scale. The Bicycle Level of Service Model was calibrated using the FLOW variable, defined as the volume of motor vehicles divided by the effective width of the road, and the level of service grades resulting from the participants evaluation. The model was validated through cross-validation methodology. The model development resulted in a graphic that can be used to determine the probability of perceived level of service for flow values found on roadways. It was considered that the study reached its primary goal, providing a Bicycle Level of Service Model that can be used in medium-sized Brazilian cities. / A presente pesquisa buscou estudar o tema da avaliação do nível de serviço para bicicletas em cidades brasileiras, com o objetivo principal de desenvolver um modelo de nível de serviço para bicicletas possível de ser utilizado em cidades brasileiras de porte médio. A metodologia utilizada para o desenvolvimento do modelo teve início com a identificação dos atributos que podem ser utilizados para descrever o nível de serviço para bicicletas, seguida pela avaliação da percepção de indivíduos sobre a importância dos atributos. Dentre os métodos disponíveis para medir a percepção dos indivíduos sobre as características viárias relacionadas ao transporte cicloviário, definiu-se pela realização de simulações, ou seja, avaliação com base em vídeo. O vídeo foi elaborado por meio de um sistema no qual uma câmera de vídeo portátil foi acoplada ao guidão da bicicleta. Para compensar a exclusão de alguns atributos que não podem ser avaliados através do vídeo (como a sensação de calor, o custo da bicicleta, os benefícios para a saúde, etc.), o método da simulação foi combinado com outro método de análise da percepção: questionários formulados com base na escala Likert. A coleta de dados foi realizada em um estudo de caso nas cidades paulistas de São Carlos e Rio Claro, em diversas instituições de ensino. No total, 451 questionários foram aplicados, sendo 60 na cidade de Rio Claro e o restante na cidade de São Carlos. Os resultados da pesquisa de campo foram analisados através de métodos de análise estatística descritiva e correlacional, produzindo os seguintes estudos: resultados dos questionários; classificação dos participantes em tipos de ciclistas; definição de uma escala de aceitabilidade ao uso da bicicleta e a classificação dos participantes em grupos, de acordo com esta escala. O Modelo de Nível de Serviço para Bicicletas foi calibrado utilizando-se a variável FLUXO, definida como o volume de veículos motorizados dividido pela largura efetiva da via, e as medidas de nível de serviço provenientes da avaliação realizada pelos participantes da pesquisa. O modelo foi validado através da metodologia da validação cruzada. O desenvolvimento do modelo resultou em um gráfico que pode ser utilizado para determinar a probabilidade da percepção de nível de serviço para valores de fluxo encontrados nas vias. Considera-se que a pesquisa atingiu o seu objetivo principal, fornecendo um Modelo de Nível de Serviço para Bicicletas que pode ser utilizado em cidades brasileiras de porte médio.