A observação de gradientes latitudinais em aspectos da história de vida de aves tem motivado o estudo da evolução e variabilidade das histórias de vida nestes organismos. Um exemplo bem documentado é a variação no tamanho da ninhada, onde aves de latitudes menores tendem a ter ninhadas menores do que os seus homólogos de latitudes altas. Uma hipótese que visa explicar esta variação propõe que a sobrevivência em latitudes tropicais é maior para compensar o tamanho da ninhada menor e evitar a extinção das populações. Esta explicação tem tido grande aceitação e apoio por parte de alguns estudos, mas tem sido questionada por outros que não encontraram taxas de sobrevivência mais elevadas em aves tropicais. De modo implícito, todos estes estudos basearam seus resultados na sobrevivência de indivíduos adultos. As populações com o tamanho da ninhada menor não poderiam crescer da mesma maneira que as populações com ninhadas maiores; portanto, se justifica acreditar que algo deve mudar com a latitude para manter o balanço em tamanho populacional. Na busca por explicações alternativas para a persistência das populações de aves tropicais com relativamente pequenos tamanhos de ninhada, surge outra hipótese que propõe que, se não houver diferenças na sobrevivência de indivíduos adultos entre latitudes, o aspecto fundamental que varia é a sobrevivência juvenil, com sobrevivência maior para os juvenis das zonas tropicais em comparação com os juvenis das zonas temperadas. No entanto, atualmente há pouca evidência que suporta esta conclusão. Os resultados contrastantes desses estudos sugerem a falta de um consenso geral sobre a hipótese de que as aves tropicais têm taxas de sobrevivência mais elevadas do que as aves de regiões temperadas, motivando a formulação de hipóteses alternativas e convidando novos testes de hipótese. Neste estudo, pretendemos a) avaliar o efeito da idade sobre a sobrevivência em aves tropicais, estimando as probabilidades anuais de sobrevivência aparentes idade-específicas para um conjunto de aves passeriformes de sub-bosque na Amazônia central brasileira; e b) contribuir para o debate sobre o gradiente latitudinal na sobrevivência de adultos, comparando nossas estimativas com estimativas de outras latitudes. Para estimar a sobrevivência idade-específica ajustamos aos nossos dados um modelo Cormack-Jolly-Seber (CJS) hierárquico para n espécies, que trata os parâmetros espécie-específicos como efeitos aleatórios, que são estimados e que descrevem todo o conjunto de espécies; para comparação de métodos, ajustamos uma versão de efeitos fixos do modelo. Para a determinação da idade das aves usamos o sistema WRP. Apresentamos uma nova variante do modelo CJS com um parâmetro de mistura para a sobrevivência de aves de idade incerta no momento da primeira captura. Encontramos efeito forte da idade na sobrevivência, com probabilidades de sobrevivência menor para os jovens do que para os adultos; evidência de efeito latitude sobre a sobrevivência, que suporta a hipótese amplamente aceita de variação na sobrevivência com a latitude; e discutimos diferenças metodológicas interessantes entre modelo de efeitos aleatórios e fixos relacionados com a precisão das estimativas e o âmbito de inferência, que nos levam a concluir que os modelos de efeitos aleatórios são os mais adequados para a nossa análise. Concluímos que não é necessário invocar uma hipótese alternativa de maior sobrevivência juvenil nos trópicos a fim de explicar o gradiente latitudinal no tamanho da ninhada. / The observation of latitudinal gradients in bird life history traits has motivated the study of avian life history evolution and variability. A well-documented example is the variation in clutch size, where lower latitude birds tend to have smaller clutches than their higher latitude counterparts. A hypothesis that explains this variation proposes that survival in tropical latitudes is higher to compensate for smaller clutch size and prevent population extinctions. This explanation has had a wide acceptance and support by some studies, but has been questioned by others who have not found such higher survival rates in tropical birds. In an implicit manner, all these studies have based their results on adult survival. Populations with smaller clutch size would not be able to grow as well as populations with larger clutches; therefore one is justified to believe that something else must change with latitude. In the search for alternative explanations to the persistence of tropical bird populations with relatively small clutch sizes it has also been proposed that, if there were no differences in adult survival among latitudes, the fundamental trait that varies is juvenile survival, with higher survival rates for tropical juveniles birds than for temperate ones. However, currently there is little evidence that supports this conclusion. The contrasting results of those studies suggest a lack of a general consensus about the hypothesis that tropical birds have higher survival rates than birds of temperate regions, motivating the formulation of alternative hypotheses, and inviting further tests of the hypothesis. In our study we aim to a) assess the effect of age on survival in a tropical bird community, estimating age-specific annual apparent survival probabilities for a set of passerine understory birds from the central Brazilian Amazon; and b) contribute to the debate about the latitudinal gradient in adult survival by comparing our adult survival estimates to estimates of temperate-zone adult survival probabilities. To estimate the age-specific survival we fit to our data a hierarchical multispecies Cormack-Jolly-Seber (CJS) model for n species, that treats species-specific parameters as random effects that are estimated and that describe the whole assemblage of species; for comparison of methods, we also fit a fixed-effects version of the model. To age birds we use the cycle-based WRP system. We introduce a novel variant of CJS model with a mixture component for the survival of birds of uncertain age at the time of banding. We found strong effect of age on survival, with juveniles surviving less than adults; evidence of latitude effect on survival, that supports the widely accepted hypothesis of variation on survival with latitude; and methodological differences between random and fixed effects model related to precision of estimates and scope of inference, that lead us to conclude that random-effects models are more appropriate for our analysis. We conclude that there is no reason for an alternative latitudinal trend in juvenile survival to account for the general trend in clutch size.

The fragmentation of rebel groups has received extensive attention from scholars and policy-makers alike. Fragmentation has been linked to an increase in civilian deaths, prolonged conflicts, and difficult peace negotiations. Despite the deliberation given to this field, this study argues that rebel governance serves as an explanatory variable that has been overlooked in the literature. This study aims to close this research gap by examining the influence of rebel governance on rebel fragmentation. The thesis suggests that rebel governance intervenes with the opportunity for rebel lieutenants to find the support of networks to create a splinter, and is successful in preventing rebel lieutenants from forming potential splinters. Therefore, it is hypothesized that rebel governance reduces the likelihood of rebel fragmentation. Using data on rebel groups active between 1946-2012, this thesis finds quantitative evidence in support of the hypothesis across all models. Furthermore, support is found that suggests that the more rebel institutions are present, the less likely it is that the rebel group fragments. Additionally, this study employs a survival model of which the results suggest that rebel groups who employ governance take longer to fragment compared to rebel groups without governance.

本研究將財務危機分為『經營不善型財務危機』以及『舞弊型財務危機』兩種類型，運用離散時間涉險方法，探討何種公司治理與財務資訊最有可能發生舞弊型的財務危機。同時本研究也探討財務危機對負債比率的敏感性如何受到公司治理中介變數的影響。 實證結果發現當公司治理機制情形不好，但財務報表資訊良好時，發生舞弊型財務危機的可能性將大於經營不善型的財務危機。而財務危機對負債比率的敏感度會受到公司治理中介變數的影響。 / With financial distress being classified as operating-failure financial distress and fraud financial distress, this study employs discrete-time survival model to characterize the fraud financial distress by corporate governance and financial performance. It also investigates the moderate effect of corporate governance on the sensitivity of financial distress to debt ratio. The empirical results indicate that companies with weak corporate governance and good financial performance are more likely to encounter fraud financial distress than operating-failure financial distress. In addition, corporate governance positively moderates the sensitivity of financial distress to debt ratio.

本文應用環境經濟學上非市場環境財估價方法－－假設市場評價法，評估北部地區四條河川（淡水河、基隆河、新店溪與大漢溪）在水質或景觀的整治時，北部地區居每人每年的願付價值，本文的目的是提供河川整治環境改善效益面的訊息，以利政府不管是作事前或事後的評估，皆可利用本研究結果的經濟效益資料作成本效益分析，以為河川整治之公共政策施政的參考與政策評估。由於，本文研究結果包括四條河川的水質與景觀在各種改善目標下之願付價值，所以，透過成本效益分析，政府在財政收支日益吃緊的情況下，可以知道在預算限制下應先整治哪一條河川可達最大經濟效益，且各河川條件不同，故整治目標的訂定亦有不同，本研究結果方可提供政府河川之環境改善目標訂定的參考依據。 　　在假設市場評價法中詢價方式有逐步競價法、支付卡、開放式問卷、封閉式問卷與假設市場序列法，本研究的問卷實驗設計採封閉式問卷中的雙界二分選擇法，實證模型採存活模型中的比例尺度模型作迴歸分析，推估受訪者在各河川、各種環境品質改善標的下的願付價值。 　　在迴歸分析中，得知影響受訪者願付價值的主要因素是，一在受訪者的特性變數中，教育程度、過去一年的戶外旅遊次數、家中汽車數與年家庭所得等變數對願付價值是正向顯著影響，而性別與年齡兩變數則是負相關。另一在環境品質變數中，景觀改善等級變數對願付價值是正向顯著影響，然而在水質改善的環境變數中，不論是目前的水質等級或是水質改善到各種不同乾淨程度的變數，都對受訪者頗付價值的影響不甚顯著。本文同時針對四條河川包括已進行整治的淡水河與基隆河，以及尚未進行整治工程的新店溪與大漢溪作環境改善效益評估，是與過去文獻主要差異之處。

本研究將財務危機分為『經營不善型財務危機』以及『掏空型財務危機』兩種類型，運用離散時間涉險方法，分析公司在不同財務狀況以及公司治理機制下，發生『經營不善型財務危機』的可能性。另外，本研究也探討『經營不善型財務危機』對公司獲利能力的敏感性，是否也受到公司治理的影響。 以民國85-94年上市櫃公司為研究對象，實證結果顯示當公司治理機制強，而財務狀況弱時，最有可能發生『經營不善而非掏空型』財務危機。再者，公司治理機制，會增強財務危機對財務狀況的敏感程度。 / This study classifies financial distress into two types: operating-failure financial distress and fraud financial distress. Based on business performance and corporate governance while employing discrete-time survival model, it analyzes the probability of the operating-failure financial distress. Furthermore, this study also examines if the sensitivity of operating-failure financial distress to profitability is moderated by corporate governance. Firms listed in Taiwan Stock Exchange during 1996-2005 are selected as sample. The empirical results indicate that firms with good corporate governance and bad business performance are most likely to encounter operating-failure financial distress. Furthermore, the corporate governance moderates the sensitivity of the operating-failure financial distress to profitability.