Burnout is a psychological concept that have got much attention since it was first defined in the middle of the 1970s. Although the definition of burnout differ there is consensus about exhaustion as the most important part of the concept. Burnout have also been in focus in sport psychology research. Mostly athletes have been studied but interest the coach profession have also been of interest. Research on coach burnout have mostly been directed towards demographic variables, organizational issues, behaviors and emotions and more holistic perspectives covering larger models or theories. The aims with this thesis was to try to fill some of the knowledge gaps from earlier coach burnout research with three studies. Study 1 aimed to study subjective experiences associated with perceived causes and symptoms of burnout and the subsequent recovery process. Eight elite soccer coaches who previously had been troubled with high scores of the exhaustion was interviewed. We found two burnout profiles that matched the coaches’ perceived causes of burnout. The first was associatedwith problems in handling the performance culture itself and the second had to do with the overall situation, including workload, family and health. Our findings describe coach burnout as stemming from a combination of issues, related to both home and work. When combined with work overload, coaches who have problems handling the performance culture in elite sports, and who lack the tools to enhance recovery, are particularly vulnerable to burnout. Study 2 focused on evaluating three self-report burnout measures that are available for researchers to use. Our analysis included Maslach Burnout Inventory (MBI), Oldenburg Burnout Inventory (OLBI) and Coach Burnout Questionnaire (CBQ). The main findings were that there are psychometric problems with all three measures and that MBI and OLBI cover similar definitions of burnout and CBQ cover somewhat different dimensions. Of the three methods that were tested CBQ seem to be most suitable for the coaching context. However, CBQ also have several problems and other burnout measures need to be evaluated in the coach context. Study 3 focused on the associations between workaholic tendencies and combining coaching job with having a family or a spouse, which can be a stressor since the work situation and family situation can be hard to combine. The main findings were that work seem to interfere more with family life than family life interfere with working live. Further workaholic tendencies and exhaustion was not associated. When interpreting the aggregated results from the thesis there are two main findings. First, the way coach burnout has been measured until now is unsatisfying. Although the development of a coach specific measure (CBQ) is promising, further development is needed, both when it comes to the theoretical aspects of the burnout construct and psychometric issues. Second, the symptoms and perceived causes in coach burnout is highly individual and makes burnout a very personal experience. Future research should focus on both the origins as well as the measurement of thisdetrimental concept. / Utbrändhet är ett psykologiskt begrepp som har fått mycket uppmärksamhet sedan den först introducerades i mitten av 1970-talet. Även om synen på vad utbrändhet är skiljer sig åt finns en enighet om att utmattning är huvudsymptomet. Utbrändhet har studerats inom idrottspsykologisk forskning sedan början av 1980-talet. Mestadels har intresset legat på idrottare men intresse har också riktats mot tränaryrket. Forskning om tränares utbrändhet har främst intresserat sig för demografiska variabler, organisationens påverkan, beteenden och känslor samt mer övergripande modeller eller teorier som täcker flera områden. Syftet med denna avhandling var att försöka fylla en del av de kunskapsluckor som funnits i tidigare forskning med tre studier. Studie 1 syftade till att studera tränares subjektiva upplevelser av utmattning kopplat till upplevda orsaker och symptom av utbrändhet samt vägen tillbaka från utbrändhet. Åtta elitfotbollstränare som tidigare hade haft problem med utmattning intervjuades. Huvudresultatet i studien var att det fanns två sätt att uppfatta utbrändhetsprocessen. Antingen såg man miljön runt elitfotbollen som den stora orsaken eller så upplevdes hela livssituationen med små stressande händelser kopplade till arbetsbelastning, familj och hälsa som problematiska. Studie 2 fokuserade på att utvärdera tre frågeformulär som är lämpliga i en tränarkontext. I analysen ingår Maslach Burnout Inventory (MBI), som oftast använts, Oldenburg Burnout Inventory (OLBI) och Coach Burnout Questionnaire (CBQ). De viktigaste resultaten var att det dels finns problem med alla tre samt att MBI och OLBI täcker liknande definitioner av utbrändhet medan CBQ mäter lite andra aspekter. Slutsatsen från studien är att CBQ verkar passa bäst för den kontext där idrottstränare arbetar även om CBQ också har en del problematiska inslag. Studie 3 fokuserade på arbetsnarkomani och att kombinera tränarjobb med familjeliv har ett samband med utmattning. Huvudresultaten i studie 3 var att det framförallt verkar vara arbetet som störa familjelivet än familjelivet som stör arbetslivet. Ytterligare fanns inget statistiskt stöd att arbetsnarkomani skulle ha ett samband med utmattning. När det sammanlagda resultatet från hela avhandlingen tolkas utifrån vilken ny kunskap denna avhandling tillför finns två huvudbidrag. Det första är att problemen med de frågeformulär som hittills använts för att mäta utbrändhet har lyfts upp. Även om det är lovande att det utvecklats ett idrottsspecifikt formulär finns tillgängligt så finns det både teoretiska och mättekniska aspekter som behöver utvecklas. Det andra bidraget är att de symptom som ingår i upplevelsen av utbrändhet verkar vara olika för olika individer. Framtida forskning bör fokusera både på hur teoretiska och mättekninska aspekter av utbrändhetsbegreppet.

企業初次公開發行(IPO，Initial Public Offering)向來是股票市場炙手可熱的話題之一，在財務經濟領域中，探討股票初次上市發行的相關議題更是多如過江之鯽，而關於IPO期初報酬率影響因素之探討更可溯及至1970年代。本研究主要係探討台灣初次上市企業期初報酬率的影響因素及影響情形，並以2005年承銷新制上路以後、直至2011年的初次上市企業為研究對象，除利用傳統的最小平方法觀察影響期初報酬的因素外，有鑑於期初報酬率普遍具有右偏分配的現象，本研究亦輔以分量迴歸分析法觀察影響期初報酬的因素，經由分量值的變動，可將解釋變數影響被解釋變數的各種情形加以估計出。再來，本研究在探討期初報酬率影響因素之基礎上，以分量迴歸分析法尋找出交易準則，並進一步檢驗當投資人遵循交易準則下，是否得以獲取顯著異於同期間大盤指數之報酬績效。在上市首日買入並持有至第五日收盤賣出之案例中，以分量迴歸結果所設定之交易準則並無法為投資人帶來顯著優於大盤指數之報酬水準；然而，在上市首日買入並持有至第二十日收盤賣出之案例，以分量迴歸結果所設定之交易準則卻可為投資人帶來顯著優於大盤指數之報酬水準。總體而言，本研究試圖將近年影響台灣企業IPO期初報酬率之因素加以剖析，進而從中尋找一些潛在規則，讓投資人得以一窺初級市場的變化及其所可能帶來之潛在獲利良機。

While Asians are overrepresented in science and engineering, they receive limited scholarly attention in sociology of science. To fill the knowledge gap about this understudied group, this study examines the effects of race, nativity, degree origin, gender, field, employment sector, and nationality on the earnings of Asian computer scientists and engineers working in the U.S. Data are derived from the National Survey of College Graduates, 1993 and 2003. Using quantile regression, this study has the following findings. First, race and nativity had some effects on the earnings of Asian computer scientists and engineers in 1993 at both 90th and 50th quantiles, but they disappeared in 2003 with one exception. Degree origin had an effect in 1993 in some cases at the 90th quantile but across gender, field, and two sectors at the 50th quantile. However, it disappeared in 2003 with two exceptions. Second, all the four women's groups--white, Asian American, U.S.-, and Asian-educated immigrant women--earned less than their male counterparts in 1993 or 2003 at either quantile. Furthermore, U.S.-educated immigrant women suffered from the double bind effect, or being disadvantaged due to both their gender and race, at the 50th quantile. Third, computer scientists earned slightly more than their engineer counterparts in both years at both quantiles. Fourth, educational institutions and state/local government paid less than industry in 1993 and 2003 at both quantiles. Federal government eliminated the gap in 2003 at the 50th quantile. Finally, this study finds that a few but not all nationality groups suffered from earning disadvantages in 1993 or 2003 at either quantile. Furthermore, the findings suggest that the earnings of workers in the upper tail (90th quantile) are less influenced by factors that this study examines than those at the median (50th quantile). Overall, the findings partly reaffirm the structural barriers that some groups, notably women, racial/ethnic minorities, and immigrants, face in the U.S. workplace. The degree origin effect in 1993 could be due to the lower quality of degrees from Asia. The disappearance of such an effect in 2003 could be due to the interactions between structural forces and human capital.

O Brasil é um dos países mais violentos do mundo, e essa realidade se reflete no ambiente escolar. O problema da violência na escola induz nos agentes de educação comportamentos que se contrapõem às metas de melhoria da qualidade do ensino. Por isso, a violência na escola é um dos candidatos a determinante da baixa qualidade educacional encontrada no Brasil. Este trabalho investiga se existe relação entre violência na escola e proficiência dos alunos no Brasil nos anos de 2003, 2005, 2007, 2009, 2011 e 2013. Os resultados das regressões lineares e das regressões quantílicas incondicionais indicam que a ocorrência de um tipo de evento violento adicional está associada a uma redução na proficiência. Eles indicam também que há heterogeneidade na resposta dos alunos à violência na escola: a violência na escola parece afetar mais os alunos da quarta série, os alunos que se encontram na mediana da distribuição das notas e os alunos com melhor condição socioeconômica. Além disso, a violência na escola parece afetar mais a proficiência em Matemática em comparação com a proficiência em Língua Portuguesa, e a violência contra o professor tem efeitos tão ou mais deletérios que a violência entre os alunos. / Brazil is one of the most violent countries in the world, and this reality is part of the school environment. The problem of school violence hinders any possible progress in improving the quality of education. Indeed, school violence is a key element in explaining the low educational quality in Brazil. This research investigates the relationship between school violence and student achievement in Brazil in the years of 2003, 2005, 2007, 2009, 2011 and 2013. The results of linear regressions and unconditional quantile regressions analysis show that an occurrence of an additional kind of violent event is associated with a reduction on student achievement. They also show that there is a high degree of heterogeneity in student responses to school violence: the school violence seems to affect more 4th graders, the students that are in the median of the distribution of the grades and the students with the best socioeconomic conditions. Moreover, school violence seems to affect more grades in Math than Portuguese, and the violence against teachers has effects as or more deleterious than the violence between students.

Le sujet principal de cette thèse est de proposer de nouvelles méthodes d'extractions de signaux avec applications en finance. Par signaux, nous entendons soit un signal sur lequel repose une stratégie d'investissement; soit un signal perturbé par un bruit, que nous souhaitons retrouver. Ainsi, la première partie de la thèse étudie la contagion en volatilité historique autours des annonces de résultats des entreprises du Nasdaq. Nous trouvons qu'autours de l'annonce, l'entreprise reportant ses résultats, génère une contagion persistante en volatilité à l’encontre des entreprises appartenant au même secteur. Par ailleurs, nous trouvons que la contagion en volatilité varie, selon le type de nouvelles reportées, l'effet de surprise, ou encore par le sentiment de marché à l'égard de l'annonceur. La deuxième partie de cette thèse adapte des techniques de dé-bruitage venant de l'imagerie, à des formes de bruits présentent en finance. Ainsi, un premier article, co-écrit avec Matthieu Garcin, propose une technique de dé-bruitage innovante, permettant de retrouver un signal perturbé par un bruit à variance non-constante. Cet algorithme est appliqué en finance à la modélisation de la volatilité. Un second travail s'intéresse au dé-bruitage d'un signal perturbé par un bruit asymétrique et leptokurtique. En effet, nous adaptons un modèle de Maximum A Posteriori, couramment employé en imagerie, à des bruits suivant des lois de probabilité de Student, Gaussienne asymétrique et Student asymétrique. Cet algorithme est appliqué au dé-bruitage de prix d'actions haute-fréquences. L'objectif étant d'appliquer un algorithme de reconnaissance de formes sur les extrema locaux du signal dé-bruité. / The main objective of this PhD dissertation is to set up new signal extraction techniques with applications in Finance. In our setting, a signal is defined in two ways. In the framework of investement strategies, a signal is a function which generates buy/sell orders. In denoising theory, a signal, is a function disrupted by some noise, that we want to recover. A first part of this PhD studies historical volatility spillovers around corporate earning announcements. Notably, we study whether a move by one point in the announcer historical volatility in time t will generate a move by beta percents in time t+1. We find evidences of volatility spillovers and we study their intensity across variables such as : the announcement outcome, the surprise effect, the announcer capitalization, the market sentiment regarding the announcer, and other variables. We illustrate our finding by a volatility arbitrage strategy. The second part of the dissertation adapts denoising techniques coming from imagery : wavelets and total variation methods, to forms of noise observed in finance. A first paper proposes an denoising algorithm for a signal disrupted by a noise with a spatially varying standard-deviation. A financial application to volatility modelling is proposed. A second paper adapts the Bayesian representation of the Rudin, Osher and Fatemi approach to asymmetric and leptokurtic noises. A financial application is proposed to the denoising of intra-day stock prices in order to implement a pattern recognition trading strategy.

[pt] Esse estudo examina a estrutura de dependência do mercado de ações do Brasil, Chile, Colômbia, México e Peru em relação aos retornos do preço de commodities, do mercado de ações global e sua volatilidade e do índice de incerteza político-econômica americana. A metodologia empregada é a regressão quantílica por permitir o exame da dependência nos diferentes quantis de distribuição dos retornos, ou seja, sob diferentes circunstâncias de mercado. Os resultados mostraram que há dependência em relação ao mercado global de ações em todos os países. De uma maneira geral, os preços das commodities também influenciam no retorno do mercado acionários da América Latina, sendo a estrutura de dependência, por vezes, assimétrica. O índice de incerteza político-econômica americano não impacta o mercado acionário de Chile e Peru, ao passo que a estrutura de dependência é assimétrica e negativa no Brasil, Colômbia e México. Por fim, o índice VIX não é significante para os retornos do mercados de ações de Brasil e Peru. Como uma contribuição adicional, foi examinada a relação de dependência do mercado acionário brasileiro em relação ao índice de incerteza político-econômico brasileiro. O estudo identificou que variações positivas do índice de incerteza político-econômico brasileiro levam a quedas no retorno acionário, quando o mercado está em ascensão. Os resultados desse estudo contribuem para a compreensão dos movimentos dos retornos do mercado acionário do Brasil e de outros países da América Latina em relação a diversos fatores, os quais são do interesse de diversos stakeholders, tais como investidores internacionais e gestores de portfólio. / [en] This study examines the dependence structure between the stock markets of Brazil, Chile, Colombia, Mexico and Peru and the commodity price, the global stock market and its volatility, and the U.S. economic-policy uncertainty index. The methodology employed is the quantile regression because it allows to exam the dependence in different quantiles of the returns distribution, that is, under different market circumstances. The results showed that there is dependence on the global stock market in all countries. In general, commodity prices also influence the stock markets of Latin America, with the dependence structure being often asymmetric. The U.S. economic-policy uncertainty index doesn t impact the stock markets of Chile and Peru, while the dependence structure is negative and asymmetric in Brazil, Colombia, and Mexico. Finally, the VIX index is not significant for the stock market returns in Brazil and Peru. As an additional contribution, the dependence of the brazilian stock market in relation to the Brazil economic-policy uncertainty index. The study identified that positive changes in the political-economic uncertainty index lead to declines in shareholder returns, when the market is bullish. The results of this study contribute to understand the movements of stock market returns in Brazil and other Latin American countries in relation to several factors, which are of interest to several stakeholders, such as international investors and portfolio managers.

O setor de saúde suplementar brasileiro operou desde os anos de 1940 sem regulação. Em 1998, o governo estabeleceu a regulação deste setor. Na regulamentação das atividades foram estabelecidas a ilimitação do número de consultas médicas, proibição de seleção de risco, entre outras medidas. O objetivo deste trabalho é investigar se a regulação resultou em aumento do número de consultas médicas por parte dos subscritores de planos de saúde, ou seja se ocorreu aumento do risco moral ex-post. Além disto, analisar alterações nos determinantes da demanda por posse de plano de saúde antes e após a regulação visando encontrar indícios de seleção adversa. Para isto, foram utilizados quatro métodos econométricos: regressão de Poisson, regressão binomial negativa e regressão quantílica de dados de contagem e um modelo Probit. O estimador de diferenças-em-diferenças foi utilizado para estimar o impacto da regulação sobre o número de consultas médicas. O modelo de regressão Probit foi utilizado para analisar os determinantes da demanda por posse de plano de saúde. Os dados utilizados provêm da Pesquisa Nacional de Amostra de Domicílios de 1998 (antes da regulação) e 2003 (depois da regulamentação). Os dados foram divididos por sexo e também pelo perfil epidemiológico, sendo selecionados os dados daqueles indivíduos que declararam ser portadores de doença renal crônica. Os resultados dos modelos mostraram que após a regulamentação ocorreu um aumento geral do número de consultas. Contudo, o sinal da principal variável de interesse, a dummy associada ao efeito da regulamentação sobre o número de consultas médicas dos subscritores de planos de saúde foi negativo e estatisticamente significativo - tanto no caso dos homens como no das mulheres - , nos três modelos e nas duas amostras. Isto indica que após a regulamentação ocorreu uma redução do número de consultas médicas dos possuidores de planos de saúde em relação àqueles que não possuíam plano de saúde. O uso da regressão quantílica possibilitou mostrar que o número de doenças crônicas e a posse de um plano de saúde são os fatores que mais afetam o número de consultas. Permitiu também mostrar que os efeitos dos regressores são diferentes entre os sexos e que não são uniformes ao longo dos quantis. Os resultados dos modelos para dados de contagem mostraram que, mesmo quando se controlam as características epidemiológicas, existe risco moral, antes e após a regulamentação. Os resultados do modelo Probit sugerem a existência de seleção adversa após a regulamentação, pois mostram que os indivíduos com maior número de morbidades têm maior probabilidade de adquirir um plano de saúde. Em suma, os resultados mostraram que após a regulamentação ocorreram dois importantes problemas no mercado de saúde suplementar: seleção adversa e risco moral. A conjunção destes dois problemas pode comprometer a sustentabilidade do setor de saúde suplementar brasileiro. / The Brazilian private health insurance sector operated since 1940’s without regulation. In 1998, the government established the regulation of this sector. The reform improved the health insurance coverage level, stating no limit to physician visits and forbiddance of the cream skimming, among others measures. The objective of this thesis is to investigate if the regulation resulted in an increase of physician visits from consumers of health insurance, that is to say, if there has been an increase of moral risk ex-post. Besides, to investigate alterations in the determinants of demand for the health insurance - before and after the regulation - seeking to find evidence or clues of adverse selection. Four econometric methods have been used for this: Poisson Regression, Negative Binominal Regression and Quantile Regression for counts and Probit Regression. The estimator of difference-in-difference was used to estimate the impact of regulation on the amount of physician visits. The Probit model regression was used to analyze the determinants of the demand for health insurance. The data used come from the 1998 Brazilian Household Survey (Pesquisa Nacional de Amostra de Domicílios-PNAD) (before the regulation) and 2003 (after the regulation). The data was divided by gender and also by the epidemiologic characteristics, selecting the data of those individuals who declared being bearers of chronic renal disease. The results of the models showed that, after the regulation, there was a general increase in the amount of consultations. However, the sign of the main variable of interest (year*regulation), the dummy associated to the effect of the regulation on physician visits of the consumers of health insurance, was negative and statistically significant – both in men and in women – in the three models and in both samples. These results suggest that after the regulation there was a reduction in the amount of physician visits of the consumers of health insurance in relation to those who did not hold a health insurance plan. The results of Probit Regression showed that after regulation there is adverse selection, since the number of chronic diseases variable after regulation was positive and statistically significant. The use of quantile regression for counts made possible showing that the number of chronic diseases and the possession of a health insurance plan are the factors which mostly affect the amount of consultations. It also allowed showing that the effects of regressors are different between the genders and also that are different in different parts of the outcome distribution. The results for the models for count data showed that, even when controlling the epidemiologic characteristics, there is a moral hazard, before and after the regulation, since individuals covered by insurance had more physician visits. The results of the Probit Model suggest the existence of adverse selection after a regulation, since it shows that individuals with a higher number of morbidities, are more likely to buy a health insurance plan. In sum, the main findings suggest that after the regulation there are two important problems: adverse selection and moral hazard. The conjunction of these two problems may generate inefficient outcomes and might compromise the sustainability of the Brazilian private health insurance market.

In this thesis, a new trading strategy is proposed. By the help of quantile regression, the conditional distribution functions of stock market returns are estimated. Based on the knowledge of the distribution the strategy produced buying and selling signals which together with a weight function derived from exponential moving averages determines how much and when to buy or sell. The strategy performs better than the market in terms of absolute return and the Sharpe ratio in-sample, but it does not provide satisfactory results out-of-sample.

O Brasil é um dos países mais violentos do mundo, e essa realidade se reflete no ambiente escolar. O problema da violência na escola induz nos agentes de educação comportamentos que se contrapõem às metas de melhoria da qualidade do ensino. Por isso, a violência na escola é um dos candidatos a determinante da baixa qualidade educacional encontrada no Brasil. Este trabalho investiga se existe relação entre violência na escola e proficiência dos alunos no Brasil nos anos de 2003, 2005, 2007, 2009, 2011 e 2013. Os resultados das regressões lineares e das regressões quantílicas incondicionais indicam que a ocorrência de um tipo de evento violento adicional está associada a uma redução na proficiência. Eles indicam também que há heterogeneidade na resposta dos alunos à violência na escola: a violência na escola parece afetar mais os alunos da quarta série, os alunos que se encontram na mediana da distribuição das notas e os alunos com melhor condição socioeconômica. Além disso, a violência na escola parece afetar mais a proficiência em Matemática em comparação com a proficiência em Língua Portuguesa, e a violência contra o professor tem efeitos tão ou mais deletérios que a violência entre os alunos. / Brazil is one of the most violent countries in the world, and this reality is part of the school environment. The problem of school violence hinders any possible progress in improving the quality of education. Indeed, school violence is a key element in explaining the low educational quality in Brazil. This research investigates the relationship between school violence and student achievement in Brazil in the years of 2003, 2005, 2007, 2009, 2011 and 2013. The results of linear regressions and unconditional quantile regressions analysis show that an occurrence of an additional kind of violent event is associated with a reduction on student achievement. They also show that there is a high degree of heterogeneity in student responses to school violence: the school violence seems to affect more 4th graders, the students that are in the median of the distribution of the grades and the students with the best socioeconomic conditions. Moreover, school violence seems to affect more grades in Math than Portuguese, and the violence against teachers has effects as or more deleterious than the violence between students.

O setor de saúde suplementar brasileiro operou desde os anos de 1940 sem regulação. Em 1998, o governo estabeleceu a regulação deste setor. Na regulamentação das atividades foram estabelecidas a ilimitação do número de consultas médicas, proibição de seleção de risco, entre outras medidas. O objetivo deste trabalho é investigar se a regulação resultou em aumento do número de consultas médicas por parte dos subscritores de planos de saúde, ou seja se ocorreu aumento do risco moral ex-post. Além disto, analisar alterações nos determinantes da demanda por posse de plano de saúde antes e após a regulação visando encontrar indícios de seleção adversa. Para isto, foram utilizados quatro métodos econométricos: regressão de Poisson, regressão binomial negativa e regressão quantílica de dados de contagem e um modelo Probit. O estimador de diferenças-em-diferenças foi utilizado para estimar o impacto da regulação sobre o número de consultas médicas. O modelo de regressão Probit foi utilizado para analisar os determinantes da demanda por posse de plano de saúde. Os dados utilizados provêm da Pesquisa Nacional de Amostra de Domicílios de 1998 (antes da regulação) e 2003 (depois da regulamentação). Os dados foram divididos por sexo e também pelo perfil epidemiológico, sendo selecionados os dados daqueles indivíduos que declararam ser portadores de doença renal crônica. Os resultados dos modelos mostraram que após a regulamentação ocorreu um aumento geral do número de consultas. Contudo, o sinal da principal variável de interesse, a dummy associada ao efeito da regulamentação sobre o número de consultas médicas dos subscritores de planos de saúde foi negativo e estatisticamente significativo - tanto no caso dos homens como no das mulheres - , nos três modelos e nas duas amostras. Isto indica que após a regulamentação ocorreu uma redução do número de consultas médicas dos possuidores de planos de saúde em relação àqueles que não possuíam plano de saúde. O uso da regressão quantílica possibilitou mostrar que o número de doenças crônicas e a posse de um plano de saúde são os fatores que mais afetam o número de consultas. Permitiu também mostrar que os efeitos dos regressores são diferentes entre os sexos e que não são uniformes ao longo dos quantis. Os resultados dos modelos para dados de contagem mostraram que, mesmo quando se controlam as características epidemiológicas, existe risco moral, antes e após a regulamentação. Os resultados do modelo Probit sugerem a existência de seleção adversa após a regulamentação, pois mostram que os indivíduos com maior número de morbidades têm maior probabilidade de adquirir um plano de saúde. Em suma, os resultados mostraram que após a regulamentação ocorreram dois importantes problemas no mercado de saúde suplementar: seleção adversa e risco moral. A conjunção destes dois problemas pode comprometer a sustentabilidade do setor de saúde suplementar brasileiro. / The Brazilian private health insurance sector operated since 1940’s without regulation. In 1998, the government established the regulation of this sector. The reform improved the health insurance coverage level, stating no limit to physician visits and forbiddance of the cream skimming, among others measures. The objective of this thesis is to investigate if the regulation resulted in an increase of physician visits from consumers of health insurance, that is to say, if there has been an increase of moral risk ex-post. Besides, to investigate alterations in the determinants of demand for the health insurance - before and after the regulation - seeking to find evidence or clues of adverse selection. Four econometric methods have been used for this: Poisson Regression, Negative Binominal Regression and Quantile Regression for counts and Probit Regression. The estimator of difference-in-difference was used to estimate the impact of regulation on the amount of physician visits. The Probit model regression was used to analyze the determinants of the demand for health insurance. The data used come from the 1998 Brazilian Household Survey (Pesquisa Nacional de Amostra de Domicílios-PNAD) (before the regulation) and 2003 (after the regulation). The data was divided by gender and also by the epidemiologic characteristics, selecting the data of those individuals who declared being bearers of chronic renal disease. The results of the models showed that, after the regulation, there was a general increase in the amount of consultations. However, the sign of the main variable of interest (year*regulation), the dummy associated to the effect of the regulation on physician visits of the consumers of health insurance, was negative and statistically significant – both in men and in women – in the three models and in both samples. These results suggest that after the regulation there was a reduction in the amount of physician visits of the consumers of health insurance in relation to those who did not hold a health insurance plan. The results of Probit Regression showed that after regulation there is adverse selection, since the number of chronic diseases variable after regulation was positive and statistically significant. The use of quantile regression for counts made possible showing that the number of chronic diseases and the possession of a health insurance plan are the factors which mostly affect the amount of consultations. It also allowed showing that the effects of regressors are different between the genders and also that are different in different parts of the outcome distribution. The results for the models for count data showed that, even when controlling the epidemiologic characteristics, there is a moral hazard, before and after the regulation, since individuals covered by insurance had more physician visits. The results of the Probit Model suggest the existence of adverse selection after a regulation, since it shows that individuals with a higher number of morbidities, are more likely to buy a health insurance plan. In sum, the main findings suggest that after the regulation there are two important problems: adverse selection and moral hazard. The conjunction of these two problems may generate inefficient outcomes and might compromise the sustainability of the Brazilian private health insurance market.