In this thesis, we address two types of modeling of random events. The first one, contained in Chapters 2 and 3, is related to the modeling of dependent stopping times. In Chapter 2, we use a modified Cox construction, along with a modification of the bivariate exponential introduced by Marshall & Olkin (1967), to create a family of stopping times, which are not necessarily conditionally independent, allowing for a positive probability for them to be equal. We also present a series of results exploring the special properties of this construction, along with some generalizations and possible applications. In Chapter 3, we present a detailed application of our model to Credit Risk theory. We propose a new measure of systemic risk that is consistent with the economic theories relating to the causes of financial market failures and can be estimated using existing hazard rate methodologies, and hence, it is simple to estimate and interpret. We do this by characterizing the probability of a market failure which is defined as the default of two or more globally systemically important banks (G-SIBs) in a small interval of time. We derive various theorems related to market failure probabilities, such as the probability of a catastrophic market failure, the impact of increasing the number of G-SIBs in an economy, and the impact of changing the initial conditions of the economy's state variables. The second type of random events we focus on is the failure of a group in the context of microlending, which is a loan made by a bank to a small group of people without credit histories. Since the creation of this mechanism by Muhammed Yunus, it has received a fair amount of academic attention. However, one of the issues not yet addressed in full detail is the issue of the size of the group. In Chapter 4, we propose a model with interacting forces to find the optimal group size. We define "optimal" as that group size that minimizes the probability of default of the group. Ultimately, we show that the original choice of Muhammad Yunus, of a group size of five people, is, under the right, and, we believe, reasonable hypotheses, either close to optimal, or even at times exactly optimal, i.e., the optimal group size is indeed five people.

No / During the subprime crisis, the FDIC has shown, once again, laxity in resolving and closing insolvent institutions. Ronn and Verma (1986) call the tolerance level below which a bank closure is triggered the regulatory policy parameter. We derive a model in which we make this parameter stochastic and bank-specific to infer the stock market view of the regulatory capital forbearance value. For 565 U.S. listed banks during 1990 to 2012, the countercyclical forbearance fraction in capital, most substantial in recessions, could represent 17%, on average, of the market valuation of bank equity and could go as high as 100%.

The recent financial crisis which has beset the United States has made itself felt in a number of ways, not the least of which has been its adverse effect on the housing market. As foreclosure percentages accelerated, increasing numbers of properties across the country became empty and abandoned, leaving a visible imprint of deterioration in neighborhoods that were significantly affected. Initial GIS analysis of both foreclosed and non-foreclosed residential land in Broward County Florida was conducted, showing that there is a discernible spectral difference in the lawn space of these two types of properties, with foreclosed properties exhibiting more brownness, or loss of green space. In order to evaluate whether or not this visible deterioration has had an effect on residents left behind in areas of foreclosure and their own habits, 950 mail-in surveys were distributed throughout 19 different census tracts in Broward County, inquiring about demographics, surrounding foreclosures, degrees of concern for home value and appearance, and changes in lawn maintenance since the foreclosure crisis along with reasons for such change if such exists. Data received from respondents was then analyzed in order to identify any attributes or correlations which might contribute to further neighborhood change, and how any of these factors might be affecting attitudes or perceptions of those left behind, as well as their lawn maintenance habits. / by Cindy M. Shaw. / Thesis (Ph.D.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

The 2007-2008 US subprime mortgage crisis evolved into a financial crisis that negatively affected many economies in the world and therefore it was widely referred to as the global financial crisis. Since the beginning of this financial crisis of 2008-2009, South Africa experienced a significant increase in its household debt to income ratio. In the main, the aim of this dissertation is to investigate the prominent factors contributing to the rise in the level of household debt in South Africa. Also, we study the response of household debt to various shocks originating from the aforementioned crisis. Additionally, in the context of our timeline (1985 Q1-2012 Q1) we will extrapolate possible graphical trends in the rise and fall of household indebtedness in South Africa associated with various crises. Working from past research papers and a theoretical framework developed by Franco Modigliani and Milton Friedman, seven macroeconomic variables will be considered to examine the rise of household borrowing to income namely; the real house price index, consumer price index. real income, real prime rate, real household consumption expenditure, real gross domestic product and real household savings. Both a long-run cointegration analysis and a short-run error correction model will be used to evaluate the relationship between household debt and the chosen variables by estimating a Vector Error Correction Model. Furthermore, the Variance Decomposition and the Generalized Impulse Response Function will be utilized to assess the impact of household debt to various shocks emanating from the 2008-2009 financial crisis. The different models and tests conducted in this research will be executed using the statistical software package EVIEWS 7. Based on the results, household debt was seen to have been fairly affected by the 2008-2009 financial crisis. The cointegration analysis maintains that in the long run, household borrowing is positively and significantly determined by consumer price index and real household consumption. In addition, it confirms that household borrowing is negatively affected by real household income and real GOP. The rest of the variables were found insignificant. Nevertheless, the short run error correction model reveals that about 3.6% of the disequilibrium will be corrected each quarter for the equilibrium state to be restored. Also, the Variance Decomposition results confirmed that the South African household debt is mostly affected by shocks from real house price index, real household income, real household consumption and real household savings, respectively. Furthermore, the Generalized Impulse Response Function results established the significant positive response of household debt to a shock from real house price index and real household consumption. The response of debt to shocks from consumer price index, real household savings and real income is negative and this outcome is confirmed by the theory. However, the response of debt shows fluctuating behaviours to shocks from LRIN, LRPR and LRGDP over the estimated period. In conclusion, our econometric investigation highlighted the main causes of the high levels of household debt in South Africa both in the short and long run. The Generalized Impulse Response Functions confirm that shocks like the occurrence of the 2007-2008 financial crisis will have a significant impact on real house price index, consumer price index, real household consumption and real household savings. The Engle granger results show that there exist no significant relationship between household debt and unemployment in South Africa over the period 1980 to 2010. However, we propose that this result may have been significant if quarterly unemployment data was available and included in the main data set. Finally, based on the stability, validity and reliability of our model, we recommend its use to facilitate policy analysis and decision making regarding household debt levels in South Africa. / Thesis (M.Com.( Economics) North-West University, Mafikeng Campus, 2012

As crises financeiras são processos de perdas decorrentes do mecanismo do mercado financeiro. Elas afetam as instituições do sistema financeiro e por meio do processo de contágio se espalham por ele, algumas vezes analogamente ao efeito dominó. Este processo pode levar muitas instituições financeiras saudáveis a se tornarem insolventes. Isso acontece porque os agentes econômicos estão interligados por meio de relações contratuais e se tornam dependentes uns aos outros. O risco sistêmico pode ser entendido como o risco de uma grande perda em um sistema. O presente trabalho tem como objetivo utilizar as propriedades de um modelo de contágio, proposto para estudar os efeitos da propagação de crises financeiras, bem como a mensuração do risco sistêmico no sistema interbancário. Este problema foi investigado considerando três diferentes topologias de rede: Erdös-Rényi, Livre de Escala (ou Scale-Free) e Interbancária Empírica. A escolha destas topologias foi pelo fato de que duas delas - Livre de Escala e Interbancária Empírica - podem emular o sistema bancário real e a de Erdös-Rényi ter sido utilizada em diversos modelos da literatura. Cada nó representa um banco que possui balanço patrimonial constituído de passivos (patrimônio líquido, empréstimos e depósitos) e ativos (empréstimos, títulos e valores mobiliários). Foi analisada a influência da alavancagem do sistema, da probabilidade inicial de default e do número de clusters da rede Interbancária Empírica. O risco sistêmico foi medido utilizando o Indicador de Risco Sistêmico, o Índice de Risco Sistêmico e o VaR Sistêmico. Mostrou-se que as redes Livres de Escala são mais robustas em relação aos ataques aleatórios evitando o aumento da inadimplência. O aumento abrupto do impacto causados pela crise acontece devido ao aumento do grau de alavancagem do sistema. O número de clusters da rede Interbancária Empírica impacta a robustez do sistema. O modelo reproduz o resultado conhecido como Muito Interconectado para Falhar, que é quando bancos mais interconectados oferecem maior risco ao sistema. / The financial crises are processes of losses arising from financial market mechanism. They affect the institutions of the financial system by the process of contagion. Sometimes it is equal to the domino effect. This process can make many healthy financial institutions become insolvents. It happens because economic agents are interconnected through contractual relations and become dependent on each other. Systemic risk can be understood as the risk of a huge loss in a system. The present work aims to study the properties of a contagion model proposed to study the effects of the spread of financial crises, as well as the measurement of systemic risk in the interbank system. This problem was investigated considering three different network topologies: Erdös-Rényi, Scale-Free and Empirical Interbank. The choice of these topologies was made by the fact that two of them - Scale-Free and Empirical Interbank - may emulate the real banking system and Erdös-Rényi has been used in several models in the literature. Each node is a bank and consists on a balance sheet split as liabilities (equity, borrowings and deposits) and assets (lendings, bonds and securities). It was analyzed the influence of the coefficient of leverage, the influence of the initial probability of default and the influence of the number of clusters on the Empirical Interbank. The systemic risk was measured using the Systemic Risk Indicator, Systemic Index and Systemic Value at Risk. It was shown that Scale-Free networks are more robust against random attacks, avoiding increases in the number of defaults. The abrupt increase in the impact caused by the crisis happens due to the increase in coefficient of leverage. The number of clusters on Empirical Interbank network impacts the robustness of the system. The model reproduces the result known as Too Interconnected to Fail, that is, banks more interconnected offer higher risk to the system.

Made available in DSpace on 2016-04-26T20:48:34Z (GMT). No. of bitstreams: 1 Mariana Neubern de Souza Almeida.pdf: 1014240 bytes, checksum: 5d712dd4c68380775fc76c6cc44c9171 (MD5) Previous issue date: 2011-06-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The emergence of the economic crisis in the United States during the years of 2007 and 2008 brought back to light the discussion on how sustainable the north-american development pattern can be and its meaning for the maintenance of neoliberalism as a capital accumulation regime. This paper analyzes the effects and characteristics of financial crises in the Unites States, considering the specificity of the neoliberal economic organization in which they are a part of. Our objective is to show, from the analysis of empirical data, that external vulnerability of the United State's economy is not the main factor responsible for the rise of crises and that these crises do not affect, in a structural way, the existent economic arrangement. Coming from interpretations on the crises of the 70s and characterizing the organization of the neoliberalism under north-american hegemony as an answer, on behalf of capital, to this crises, we intend to highlight the fact that the present financial crises can play a functional roll to the reproduction of capital and its effects, from this point of view, may be just bearable illnesses of the system / A eclosão da crise econômica nos Estados Unidos entre os anos de 2007 e 2008 deu nova luz ao debate sobre a sustentabilidade dos padrões de desenvolvimento da economia norteamericana e o seu significado para a continuidade do neoliberalismo como regime de acumulação do capital. Este trabalho analisa os efeitos e as características das crises financeiras ocorridas nos Estados Unidos considerando a particularidade da organização econômica neoliberal na qual elas estão inseridas. Nosso objetivo é mostrar, a partir da análise dos dados empíricos, que a vulnerabilidade externa da economia dos Estados Unidos não é um fator decisivo para o aprofundamento dessas crises e que estas não necessariamente afetam, de modo estrutural, o arranjo econômico atualmente existente. Partindo de interpretações sobre a crise dos anos 70 e caracterizando a organização do neoliberalismo sob hegemonia norte-americana como uma resposta, por parte do capital, a essa crise, buscamos ressaltar que as atuais crises financeiras podem ter um papel funcional à reprodução do capital, sendo seus efeitos, deste ponto de vista, males suportáveis

Made available in DSpace on 2016-04-25T16:44:36Z (GMT). No. of bitstreams: 1 Theresangela Giongo Flores Araes.pdf: 2525517 bytes, checksum: db1eeaec5b8908720990db4db74213b2 (MD5) Previous issue date: 2013-10-15 / The bankruptcy of Lehman Brothers in 2008 rapidly provoked a severe systemic risk in the global banking industry and resulted in the worst financial crisis since the Great Depression in 1929. This crisis affected the Brazilian Financial System, contributing to the adoption of several prudential measures to soften their effects. As a consequence of such crisis, the European fiscal crisis started in mid-2010, with new expansive measures being adopted in Brazil in 2011. This study evaluated how these international financial crises and prudential measures adopted by the Brazilian Central Bank affected the stock and the financial performance of Brazilian Banks. It was used the methodology of event study and of financial analysis based on the evaluation of accounting indexes, which are traditional in the banking system (CAMELS). It was noticed that the stock performance of the banks, in general, was not statistically affected by the selected events. This behavior can be partially explained by the dynamic nature of the events, which only happen after consecutive disclosure of relevant information about the economic environment and the companies to the market. Regarding the financial performance, it was noticed that, in moments of crises, the banks adopt a more conservative posture towards credit concession, due to higher delinquencies and lower profitability. Banks focus on improving their liquidity conditions. Despite overall negative impact of financial crises over the banks profitability and asset quality of Brazilian Banks, the strong capital structure of the banking system allowed the absorption of such losses / A falência do Lehman Brothers em 2008 rapidamente desencadeou um severo risco sistêmico no mercado bancário global e resultou na pior crise financeira desde a Grande Depressão em 1929. Esta crise afetou o sistema financeiro brasileiro, provocando a adoção de diversas medidas prudenciais para combater seus efeitos. Como desdobramento desta crise, surgiu a crise fiscal européia em meados de 2010 com novas medidas expansionistas sendo adotadas no Brasil em 2011. O presente trabalho avaliou como estas crises financeiras internacionais e as medidas prudenciais adotadas pelo Banco Central do Brasil afetaram o desempenho bursátil e contábil dos bancos brasileiros. Para isso, foram utilizados os métodos de estudo de eventos e a análise financeira baseada na leitura de índices contábeis tradicionais do segmento bancário (CAMELS). Percebeu-se que o desempenho bursátil dos bancos, de modo geral, não foi afetado de forma estatisticamente significativa pelos eventos sistêmicos selecionados. Em parte, tal comportamento pode ser explicado pela natureza dinâmica dos eventos, os quais somente são deflagrados após a divulgação sequencial de informações relevantes da conjuntura econômica e de empresas ao mercado. Quanto ao desempenho financeiro , constatou-se que em momentos de crise, os bancos adotaram uma postura mais cautelosa na concessão de crédito, resultante de aumento de inadimplência e queda de rentabilidade, concentrando esforços na construção de liquidez. Mesmo com os impactos negativos das crises financeiras sobre a rentabilidade e qualidade de ativos do bancos brasileiros estudados nesta pesquisa, a forte estrutura de capital do sistema bancário, permitiu a absorção de tais perdas

As crises financeiras são processos de perdas decorrentes do mecanismo do mercado financeiro. Elas afetam as instituições do sistema financeiro e por meio do processo de contágio se espalham por ele, algumas vezes analogamente ao efeito dominó. Este processo pode levar muitas instituições financeiras saudáveis a se tornarem insolventes. Isso acontece porque os agentes econômicos estão interligados por meio de relações contratuais e se tornam dependentes uns aos outros. O risco sistêmico pode ser entendido como o risco de uma grande perda em um sistema. O presente trabalho tem como objetivo utilizar as propriedades de um modelo de contágio, proposto para estudar os efeitos da propagação de crises financeiras, bem como a mensuração do risco sistêmico no sistema interbancário. Este problema foi investigado considerando três diferentes topologias de rede: Erdös-Rényi, Livre de Escala (ou Scale-Free) e Interbancária Empírica. A escolha destas topologias foi pelo fato de que duas delas - Livre de Escala e Interbancária Empírica - podem emular o sistema bancário real e a de Erdös-Rényi ter sido utilizada em diversos modelos da literatura. Cada nó representa um banco que possui balanço patrimonial constituído de passivos (patrimônio líquido, empréstimos e depósitos) e ativos (empréstimos, títulos e valores mobiliários). Foi analisada a influência da alavancagem do sistema, da probabilidade inicial de default e do número de clusters da rede Interbancária Empírica. O risco sistêmico foi medido utilizando o Indicador de Risco Sistêmico, o Índice de Risco Sistêmico e o VaR Sistêmico. Mostrou-se que as redes Livres de Escala são mais robustas em relação aos ataques aleatórios evitando o aumento da inadimplência. O aumento abrupto do impacto causados pela crise acontece devido ao aumento do grau de alavancagem do sistema. O número de clusters da rede Interbancária Empírica impacta a robustez do sistema. O modelo reproduz o resultado conhecido como Muito Interconectado para Falhar, que é quando bancos mais interconectados oferecem maior risco ao sistema. / The financial crises are processes of losses arising from financial market mechanism. They affect the institutions of the financial system by the process of contagion. Sometimes it is equal to the domino effect. This process can make many healthy financial institutions become insolvents. It happens because economic agents are interconnected through contractual relations and become dependent on each other. Systemic risk can be understood as the risk of a huge loss in a system. The present work aims to study the properties of a contagion model proposed to study the effects of the spread of financial crises, as well as the measurement of systemic risk in the interbank system. This problem was investigated considering three different network topologies: Erdös-Rényi, Scale-Free and Empirical Interbank. The choice of these topologies was made by the fact that two of them - Scale-Free and Empirical Interbank - may emulate the real banking system and Erdös-Rényi has been used in several models in the literature. Each node is a bank and consists on a balance sheet split as liabilities (equity, borrowings and deposits) and assets (lendings, bonds and securities). It was analyzed the influence of the coefficient of leverage, the influence of the initial probability of default and the influence of the number of clusters on the Empirical Interbank. The systemic risk was measured using the Systemic Risk Indicator, Systemic Index and Systemic Value at Risk. It was shown that Scale-Free networks are more robust against random attacks, avoiding increases in the number of defaults. The abrupt increase in the impact caused by the crisis happens due to the increase in coefficient of leverage. The number of clusters on Empirical Interbank network impacts the robustness of the system. The model reproduces the result known as Too Interconnected to Fail, that is, banks more interconnected offer higher risk to the system.

Uma característica dominante do sistema financeiro contemporâneo é a intrincada rede de conexões entre instituições financeiras, destacando-se a rede de empréstimos do mercado interbancário, através da qual é feita a transferência de recursos líquidos de bancos com superavit de liquidez para bancos deficitários. Ao mesmo tempo em que o mercado interbancário é responsável pela alocação eficiente de liquidez, a estrutura das exposições interbancárias pode ser considerada fator de risco sistêmico por ser fonte de contágio em caso de crise financeira. A insolvência de um banco pode se propagar na rede levando à insolvência de um grande subconjunto conectado de bancos. Estudos empíricos tem evidenciado que algumas redes interbancárias apresentam características de redes livres de escala. O presente trabalho explora as características de contágio financeiro em redes cuja distribuição de links se aproxima a uma lei de potência, através de um modelo deliberadamente simplificado que define a estrutura patrimonial dos bancos a partir de informações de conectividade da rede. Variando os parâmetros de formação das redes obtemos distribuições com diferentes concentrações de dívidas e de direitos, criando três perfis principais, que foram analisados quanto a sua resistência ao contágio. Testamos também o efeito da variação da conectividade em conjunto com a variação da concentração dos links. Os resultados encontrados sugerem que redes mais conectadas e com alta concentração de direitos (com nodos caracterizados por serem grandes credores do sistema) apresentam maior resistência ao contágio. Avaliando alguns índices topológicos de risco sistêmico sugeridos na literatura, pudemos verificar sua capacidade de explicar o impacto da quebra de um nodo sobre o sistema. Embora fique evidente a relação positiva entre os índices e o valor do impacto para os casos de maior magnitude de perdas, a relação é mais fraca para os menores valores de impacto, sugerindo um poder menor de previsão em redes mais resistentes. / One of the most striking characteristics of modern financial systems is its complex interdependence, standing out the network of bilateral exposures in interbank market, through which institutions with surplus liquidity can lend to those with liquidity shortage. While the interbank market is responsible for efficient liquidity allocation, it also introduce the possibility for systemic risk via financial contagion. Insolvency of one bank can propagate through interlinkages leading to insolvency of other banks. Empirical studies have shown that some interbank networks have features of scalefree networks. This work explores the characteristics of financial contagion in networks whose links distributions approaches a power law, using a deliberately simplified model that defines banks balance sheets from information of network connectivity. Varying the parameters of the network creation we obtained links distributions with different concentrations of debts and rights, creating three main network types, which were analyzed for their resilience to contagion. We also tested the effect of a variation in connectivity in conjunction with variation in concentration of links. The results suggest that more connected networks with high concentration of rights (featuring nodes that are large creditors of the system) present greater resilience to contagion. Evaluating some topological indices of systemic risk suggested in the literature, we could verify its ability to explain the impact on the system caused by the failure of a node. While it is clear the positive relationship between the indexes and the impact value for cases of greater magnitude of losses, the relationship is weaker for smaller values of impact, suggesting a lower predictive power in more resilient networks.

1997年亞洲匯率危機的發生，引發學者對於危機發生原因的論戰。對於亞洲匯率危機發生的國家而言，究竟那些匯率危機理論具有解釋能力？又匯率危機是否是可以透過基本面的指標來預測的？假使可以效力又是如何？本文中為了回答這些問題，於是使用東亞六國包含印尼、韓國、馬來西亞、菲律賓、新加坡、泰國六個開發中國家1971-1998年的收據資料，並運用Probit的計量模型來進行實證研究。 本文實證結果發現，在匯率危機理論的解釋上，第一代匯率危機理論的論述，並不足以完全解釋東亞地區的發展中國家匯率危險的發生，必須再加上第二代的匯率危機理論的論述，才能完整找出東亞發展中國家匯率危機發生的決定因素。再者，在東亞地區發展中國家的匯率危機發生前，其基本面情況的確是程現亞化的趨勢。但是基本面惡化程度，並不足以單獨決定匯率危機的發生，必預加入除了基本面惡化程度，並不足以單獨決定匯率危機的發生，必須加入除了基本面以外，其它會影響投資人的行為和預期因素，如市場資訊不完全而造成群眾的盲從效果以及跨國的漫延效果......等等，綜合起來最後才會導致投機性攻擊而引發危機。換句話說，當政府在進行施政決策或者是投資人在進行經濟決策時，基本面因素或許不是政府或投資人唯一的考量，但卻是重要的考量之一。 另外，針對東亞地區匯率危機是否是可以預警以及預警效力如何的問題。經由實證結果，我們認為答案是肯定的，不論是從樣本內或樣本外來看這組解釋變數的指標的預測效力，都有超過百分之七十的預測水準。