Hipóteses precisas são características naturais das teorias econômicas de determinação do valor ou preço de ativos financeiros. Nessas teorias, a precisão das hipóteses assume a forma do conceito de equilíbrio ou da não arbitragem. Esse último possui um papel fundamental nas teorias de finanças. Sob certas condições, o Teorema Fundamental do Apreçamento de Ativos estabelece um sistema único e coerente para valorização dos ativos em mercados não arbitrados, valendo-se para tal das formulações para processos de martingal. A análise da distribuição estatística desses ativos financeiros ajuda no entendimento de como os participantes se comportam nos mercados, gerando assim as condições para se arbitrar. Nesse sentido, a tese defendida é a de que o estudo da hipótese de não arbitragem possui contrapartida científica, tanto do lado teórico quanto do empírico. Utilizando-se do modelo estocástico Variância Gama para os preços dos ativos, o teste Bayesiano FBST é implementado com o intuito de se verificar a existência da arbitragem nos mercados, potencialmente expressa nos parâmetros destas densidades. Especificamente, a distribuição do Índice Bovespa é investigada, com os parâmetros risco-neutros sendo estimados baseandose nas opções negociadas no Segmento de Ações e no Segmento de Derivativos da BM&FBovespa. Os resultados aparentam indicar diferenças estatísticas significantes em alguns períodos de tempo. Até que ponto esta evidência é a expressão de uma arbitragem perene nesses mercados ainda é uma questão em aberto. / Precise hypotheses are natural characteristics of the economic theories for determining the value or prices of financial assets. Within these theories the precision is expressed in terms of equilibrium and non-arbitrage hypotheses. The former concept plays an essential role in the theories of finance. Under certain conditions, the Fundamental Theorem of Asset Pricing establishes a coherent and unique asset pricing framework in non-arbitraged markets, grounded on martingales processes. Accordingly, the analysis of the statistical distributions of financial assets can assist in understanding how participants behave in the markets, and may or may not engender conditions to arbitrage. On this regard, the dissertation proposes that the study of non-arbitrage hypothesis has a scientific counterparty, theoretically and empirically. Using a variance gamma stochastic model for prices, the Bayesian test FBST is conducted to verify the presence of arbitrage potentially incorporated on these densities parameters. Specifically, the Bovespa Index distribution is investigated, with risk neutral parameters estimated based on options traded in the Equities Segment and the Derivatives Segment at the BM&FBovespa Exchange. Results seem to indicate significant statistical differences at some periods of time. To what extent this evidence is actually the expression of a perennial arbitrage between the markets still is an open question.

Incapaz de tematizar a conexão interna do valor com as diversas formas sociais que constituem o modo de produção capitalista, a Economia Política não consegue desvendar as tendências imanentes deste modo peculiar de organização da vida material da sociedade, o que a impede de interpretar de maneira consistente o devir histórico da economia capitalista como um todo, bem como o de suas formas particulares consideradas individualmente. Neste trabalho, veremos que tal deficiência fica particularmente clara nas considerações dos economistas sobre o capital acionário (parte I). Marx, ao se propor desenvolver logicamente as formas através das quais a lei do valor pode se impor sobre o metabolismo social, supera a unilateralidade da Economia Política (parte II). No entanto, ele não esclarece exatamente como deve ser pensada a relação entre o desenvolvimento lógico-sistemático das formas da economia burguesa e o devir histórico dessas formas propriamente dito. Por isso, após deduzir a forma-valor capital acionário, proporemos, com base nas semelhanças entre o conceito marxiano de capital e o sujeito absoluto apresentado por Hegel, uma interpretação da história do capital acionário inspirada na filosofia hegeliana da história (parte III). Finalmente, depois de constatar que, apesar de sua proficuidade, a interpretação em moldes hegelianos da história do capital acionário não é plenamente consistente, tentaremos evidenciar a incompatibilidade entre o Espírito Absoluto hegeliano e o conceito marxiano de capital, o que nos permitirá empreender uma interpretação das transformações recentes do capital acionário inspirada na Crítica da Economia Política (parte IV). / Incapable of conceiving the unity of the value-form with the other forms of the capitalist mode of production, Political Economy cannot reveal the internal tendencies of the capitalist economy as such. Consequently, it cannot understand the historical developments of this kind of economic organization. This incapability gets particularly clear when one examines economic theories on share capital. Through the logical development of the forms of value, Marx overcame such limits of Political Economy. What he did not clarify however was how one should conceive the relation between the logical development of the forms of value and the historical development of capital as such. Based on the similarities between Marx\'s concept of capital and Hegel\'s concept of Absolute Spirit, we will test the hypothesis that the latest transformations of share capital can be understood as a result of its increasing conformation to its concept. We shall see that although it can help us understanding some features of these transformations, a hegelian interpretation of it is not fully consistent. That is why, after revealing the most important differences between the hegelian concept of absolute spirit and the marxian concept of capital, we shall try to comprehend how exactly the Critique of Political Economy can help us understanding historical changes in the capitalist mode of production, and particularly the latest historical developments of share capital.

Global warming is affecting the Earth climate year by year, the biggest difference being observable in increasing temperatures in the World Ocean. Following the long- term global ocean warming trend, average sea surface temperatures across the global tropics and subtropics have increased by 0.4–1◦C in the last 40 years. These rates become even higher in semi-enclosed southern seas, such as the Red Sea, threaten- ing the survival of thermal-sensitive species. As average sea surface temperatures are projected to continue to rise, careful study of future developments of extreme temper- atures is paramount for the sustainability of marine ecosystem and biodiversity. In this thesis, we use Extreme-Value Theory to study sea surface temperature extremes from a gridded dataset comprising 16703 locations over the Red Sea. The data were provided by Operational SST and Sea Ice Analysis (OSTIA), a satellite-based data system designed for numerical weather prediction. After pre-processing the data to account for seasonality and global trends, we analyze the marginal distribution of ex- tremes, defined as observations exceeding a high spatially varying threshold, using the Generalized Pareto distribution. This model allows us to extrapolate beyond the ob- served data to compute the 100-year return levels over the entire Red Sea, confirming the increasing trend of extreme temperatures. To understand the dynamics govern- ing the dependence of extreme temperatures in the Red Sea, we propose a flexible local approach based on R-Pareto processes, which extend the univariate Generalized Pareto distribution to the spatial setting. Assuming that the sea surface temperature varies smoothly over space, we perform inference based on the gradient score method over small regional neighborhoods, in which the data are assumed to be stationary in space. This approach allows us to capture spatial non-stationarity, and to reduce the overall computational cost by taking advantage of distributed computing resources. Our results reveal an interesting extremal spatial dependence structure: in particular, from our estimated model, we conclude that significant extremal dependence prevails for distances up to about 2500 km, which roughly corresponds to the Red Sea length.

Hipóteses precisas são características naturais das teorias econômicas de determinação do valor ou preço de ativos financeiros. Nessas teorias, a precisão das hipóteses assume a forma do conceito de equilíbrio ou da não arbitragem. Esse último possui um papel fundamental nas teorias de finanças. Sob certas condições, o Teorema Fundamental do Apreçamento de Ativos estabelece um sistema único e coerente para valorização dos ativos em mercados não arbitrados, valendo-se para tal das formulações para processos de martingal. A análise da distribuição estatística desses ativos financeiros ajuda no entendimento de como os participantes se comportam nos mercados, gerando assim as condições para se arbitrar. Nesse sentido, a tese defendida é a de que o estudo da hipótese de não arbitragem possui contrapartida científica, tanto do lado teórico quanto do empírico. Utilizando-se do modelo estocástico Variância Gama para os preços dos ativos, o teste Bayesiano FBST é implementado com o intuito de se verificar a existência da arbitragem nos mercados, potencialmente expressa nos parâmetros destas densidades. Especificamente, a distribuição do Índice Bovespa é investigada, com os parâmetros risco-neutros sendo estimados baseandose nas opções negociadas no Segmento de Ações e no Segmento de Derivativos da BM&FBovespa. Os resultados aparentam indicar diferenças estatísticas significantes em alguns períodos de tempo. Até que ponto esta evidência é a expressão de uma arbitragem perene nesses mercados ainda é uma questão em aberto. / Precise hypotheses are natural characteristics of the economic theories for determining the value or prices of financial assets. Within these theories the precision is expressed in terms of equilibrium and non-arbitrage hypotheses. The former concept plays an essential role in the theories of finance. Under certain conditions, the Fundamental Theorem of Asset Pricing establishes a coherent and unique asset pricing framework in non-arbitraged markets, grounded on martingales processes. Accordingly, the analysis of the statistical distributions of financial assets can assist in understanding how participants behave in the markets, and may or may not engender conditions to arbitrage. On this regard, the dissertation proposes that the study of non-arbitrage hypothesis has a scientific counterparty, theoretically and empirically. Using a variance gamma stochastic model for prices, the Bayesian test FBST is conducted to verify the presence of arbitrage potentially incorporated on these densities parameters. Specifically, the Bovespa Index distribution is investigated, with risk neutral parameters estimated based on options traded in the Equities Segment and the Derivatives Segment at the BM&FBovespa Exchange. Results seem to indicate significant statistical differences at some periods of time. To what extent this evidence is actually the expression of a perennial arbitrage between the markets still is an open question.

Incapaz de tematizar a conexão interna do valor com as diversas formas sociais que constituem o modo de produção capitalista, a Economia Política não consegue desvendar as tendências imanentes deste modo peculiar de organização da vida material da sociedade, o que a impede de interpretar de maneira consistente o devir histórico da economia capitalista como um todo, bem como o de suas formas particulares consideradas individualmente. Neste trabalho, veremos que tal deficiência fica particularmente clara nas considerações dos economistas sobre o capital acionário (parte I). Marx, ao se propor desenvolver logicamente as formas através das quais a lei do valor pode se impor sobre o metabolismo social, supera a unilateralidade da Economia Política (parte II). No entanto, ele não esclarece exatamente como deve ser pensada a relação entre o desenvolvimento lógico-sistemático das formas da economia burguesa e o devir histórico dessas formas propriamente dito. Por isso, após deduzir a forma-valor capital acionário, proporemos, com base nas semelhanças entre o conceito marxiano de capital e o sujeito absoluto apresentado por Hegel, uma interpretação da história do capital acionário inspirada na filosofia hegeliana da história (parte III). Finalmente, depois de constatar que, apesar de sua proficuidade, a interpretação em moldes hegelianos da história do capital acionário não é plenamente consistente, tentaremos evidenciar a incompatibilidade entre o Espírito Absoluto hegeliano e o conceito marxiano de capital, o que nos permitirá empreender uma interpretação das transformações recentes do capital acionário inspirada na Crítica da Economia Política (parte IV). / Incapable of conceiving the unity of the value-form with the other forms of the capitalist mode of production, Political Economy cannot reveal the internal tendencies of the capitalist economy as such. Consequently, it cannot understand the historical developments of this kind of economic organization. This incapability gets particularly clear when one examines economic theories on share capital. Through the logical development of the forms of value, Marx overcame such limits of Political Economy. What he did not clarify however was how one should conceive the relation between the logical development of the forms of value and the historical development of capital as such. Based on the similarities between Marx\'s concept of capital and Hegel\'s concept of Absolute Spirit, we will test the hypothesis that the latest transformations of share capital can be understood as a result of its increasing conformation to its concept. We shall see that although it can help us understanding some features of these transformations, a hegelian interpretation of it is not fully consistent. That is why, after revealing the most important differences between the hegelian concept of absolute spirit and the marxian concept of capital, we shall try to comprehend how exactly the Critique of Political Economy can help us understanding historical changes in the capitalist mode of production, and particularly the latest historical developments of share capital.

In the aftermath of the Great Recession of 2007-2009, banking executives feared the impact of increased capital reserve requirements for losses from mortgage defaults. One reason was that home price declines during the Great Recession precipitated mortgage defaults, which increased the percentage of foreclosures as well as accelerated negative equity, and default. The purpose of this correlational study, grounded in Fishbein's expectancy of value and Vroom's expectancy theories, was to examine the relationship between the independent variables of homeowner's equity, rental cash flow value, and recourse, and the dependent variable, default mortgage status. Archival data comprised a sample of 408 single family residences in Alameda County, California, and Shelby, Fayette, and Tipton Counties in Tennessee. The results of the binary logistic regression model indicated the model was a good fit to predict a significant relationship between the variables (Ï?2 = 3.490, p = 0.322, df = 3). The findings did not reveal a significant relationship between homeowner's equity, rental cash flow value, recourse, and default mortgage status. Therefore, the independent variables did not predict mortgage default status. However, a minor relationship was found between homeowner's equity (p = 0.215), rental cash flow value (p = 0.215), and default mortgage status. A non-significant relationship between the independent variables and default mortgage status indicated that factors other than the study variables influenced default mortgage status. Advocates for fair housing laws may use study findings to encourage lenders to change lending policies to reduce the risk of default and increase stability in local communities, which may result in potential positive social change.

This thesis investigated children's school achievement in terms of an integration of three theories of achievement motivation. The three theoretical outlooks were expectancy-value theory (EVT), implicit theories of intelligence (ITI), and flow theory (FT). The first of two studies was an exploratory investigation of the effectiveness of each theory independently and combined to predict children's achievement in four school subjects. The subject areas were maths, reading, instrumental music and sport. Participants were 84 children (40 females and 44 males) aged 9 to 10 years, one of each child's parents, and school teachers of each child in the four subject areas. All data were collected through questionnaires based on the three models. The results indicated that EVT and FT but not ITI accounted for a significant amount of the variance in children's achievement, including effects for subject area and gender. A second confirmatory study tested EVT, FT and an integrated model for the prediction of achievement in maths, reading and instrumental music. The participants were a further 141 children (74 females and 67 males) aged 10 to 11 years, and a parent and teachers of each child. Data collection using questionnaires occurred early in the school year (Timel) and approximately five months later (Time2). For EVT, children and parents’ competence beliefs were significant predictors of children's achievement in each subject area. Females tended to believe themselves more competent at reading and instrumental music and also valued these subjects more highly than boys. Modeling results for flow theory indicated that children's emotional responses to classes (happiness and confusion) were significant predictors of achievement, the type of emotion varying between subject areas and time periods. Females generally had a more positive emotional reaction to reading and instrumental music classes than males did. The integrated model results indicated significant relationships between EVT and flow theories for each subject area, with EVT explaining most achievement variance in the integrated model. Children's and parents’ competence beliefs were the main predictors of achievement at Timel and 2, Subject area and gender differences were found which provide direction for future research. Anecdotal reports of parents and teachers often attest to individual differences in children's involvement in various school domains. Even among children of apparently similar intelligence, it is not uncommon to find one who likes nothing better than to work on a mathematics problem while another much prefers to read a novel or play a musical instrument Some children appear to achieve good results for most of the activities in which they are engaged while others achieve in a less consistent manner, sometimes particularly excelling in one activity. Some children respond to failure experiences with a determination to improve their performance in the future while others react with resignation and acceptance of their low ability. Some children appear to become totally absorbed in the activity of playing sport while others cannot wait for the game to end. The primary research objective guiding the current thesis is how children's thoughts and feelings about school subjects differ and are related to their school achievement. A perusal of the achievement motivation literature indicates several possible models and concepts that can be applied to explain individual differences in children's school achievement. Concepts such as academic self-concept, multiple intelligences, intrinsic and extrinsic motivation, self-beliefs, competence beliefs, subjective task values, mastery and performance goals, ‘Flow’ experiences and social motivation are just some of the constructs used to explain children's achievement motivation, both within and between various activity domains. These constructs are proposed by researchers from different theoretical perspectives to achievement motivation. Although there is much literature relevant to each perspective, there is little research indicating how the various perspectives may relate to each other. The current thesis will begin by reviewing three currently popular theoretical orientations cited in achievement motivation research: subjective beliefs and values; implicit theories of intelligence, and flow experience and family complexity. Following this review, a framework will be proposed for testing the determinants of children's school achievement, both within each of the three theoretical perspectives and also in combination.

The current study empirically analyzes the extreme behavior and the impact of deregulation policies as well as financial turmoil on the extreme behavior of changes of Taiwan short term interest rate. A better knowledge of short-term interest rate properties, such as heavy tails, asymmetry, and uneven tail fatness between right and left tails, provide an insight to the extreme behavior of short-term interest rate as well as a more accurate estimation of interest risk. The predicting performances of filtered and unfiltered VaR (Value at risk) models are also examined to suggest the proper models for management of interest rate risk. By applying Extreme Value theory (EVT), tail behavior is analyzed and tested and the VaR based on parametric and non-parametric EVT models are calculated.The empirical findings show that, first, the distribution of change of rate are heavy-tailed indicating that the actual risk would be underestimated based on normality assumption. Second, the unconditional distribution is consistent with the heavier-tailed distributions such as ARCH process or Student¡¦t. Third, the right tail of distribution of change of rate are significantly heavier than the left one pointing out that the probabilities and magnitudes of rise in rate could be higher than those of drop in rate. Fourth, the amount of tail-fatness in tail of distribution of change of rate increase after 1999 and the vital factors to cause structural break in tail index are the interest rate policies taken by central bank of Taiwan instead of the deregulation policies in money market. Fifth, based on the two break points found in tail index of right and left tail, long sample of CP rates should not be treated as samples from a single distribution. Sixth, the dependent and heteroscedastic properties of data series should be considered in applying EVT to improve accuracy of VaR forecasts. Finally, EVT models predict VaR accurately before 2001 and the benchmark model, HS and GARCH, generally are superior to EVT models after 2001. Among EVT models, MRE and CHE are relative consistent and reliable in VaR prediction.

The recent elevated North Atlantic hurricane activity has generated considerable interests in the interaction between tropical cyclones (TCs) and climate change. The possible connection between TCs and the changing climate has been indicated by observational studies based on historical TC records; they indicate emerging trends in TC frequency and intensity in some TC basins, but the detection of trends has been hotly debated due to TC track data issues. Dynamical climate modeling has also been applied to the problem, but brings its own set of limitations owing to limited model resolution and uncertainties. The final goal of this study is to project the future changes of North Atlantic TC behavior with global warming for the next 50 years using the Nested Regional Climate Model (NRCM). Throughout the course of reaching this goal, various uncertainties and limitations in simulating TCs by the NRCM are identified and explored. First we examine the TC tracking algorithm to detect and track simulated TCs from model output. The criteria and thresholds used in the tracking algorithm control the simulated TC climatology, making it difficult to objectively assess the model's ability in simulating TC climatology. Existing tracking algorithms used by previous studies are surveyed and it is found that the criteria and thresholds are very diverse. Sensitivity of varying criteria and thresholds in TC tracking algorithm to simulated TC climatology is very high, especially with the intensity and duration thresholds. It is found that the commonly used criteria may not be strict enough to filter out intense extratropical systems and hybrid systems. We propose that a better distinction between TCs and other low-pressure systems can be achieved by adding the Cyclone Phase technique. Two sets of NRCM simulations are presented in this dissertation: One in the hindcasting mode, and the other with forcing from the Community Climate System Model (CCSM) to project into the future with global warming. Both of these simulations are assessed using the tracking algorithm with cyclone phase technique. The NRCM is run in a hindcasting mode for the global tropics in order to assess its ability to simulate the current observed TC climatology. It is found that the NRCM is capable of capturing the general spatial and temporal distributions of TCs, but tends to overproduce TCs particularly in the Northwest Pacific. The overpredction of TCs is associated with the overall convective tendency in the model added with an outstanding theory of wave energy accumulation leading to TC genesis. On the other hand, TC frequency in the tropical North Atlantic is under predicted due to the lack of moist African Easterly Waves. The importance of high-resolution is shown with the additional simulation with two-way nesting. The NRCM is then forced by the CCSM to project the future changes in North Atlantic TCs. An El Nino-like SST bias in the CCSM induced a high vertical wind shear in tropical North Atlantic, preventing TCs from forming in this region. A simple bias correction method is applied to remove this bias. The model projected an increase both in TC frequency and intensity owing to enhanced TC genesis in the main development region, where the model projects an increased favorability of large-scale environment for TC genesis. However, the model is not capable of explicitly simulating intense (Category 3-5) storms due to the limited model resolution. To extrapolate the prediction to intense storms, we propose a hybrid approach that combines the model results and a statistical modeling using extreme value theory. Specifically, the current observed TC intensity is statistically modeled with the General Pareto distribution, and the simulated intensity changes from the NRCM are applied to the statistical model to project the changes in intense storms. The results suggest that the occurrence of Category 5 storms may be increased by approximately 50% by 2055.

In this work were considered the maxima and minima structures. Where number of value is random and is distributed by negative binomial distribution. There were theorems that were improved in this work, that helped to find the limit distribute function of this standard structures. These theorems generalize propositions, when set size is geometric random number. Also, there was the concrete distribution analysis done and such distributions were chosen: exponential, general logistic and uniform.