受2008年金融海嘯影響，人壽保險業因資本及信用市場之系統性風險而導致帳列資產價值大幅減損，進一步影響壽險公司清償能力，而主管機關為兼顧審慎監理與市場穩定原則，而採行資本監理寬容措施，卻使得資本不足之保險公司缺口擴大。另外，保險安定基金以保費為基礎徵收單一費率，加劇保險公司間交叉補貼之情形。因此，如何透過以責任準備金為基礎，計算公平合理之風險差別費率，以避免產生影響其他保險公司正常經營之系統性風險，抑或引發保險公司道德風險，為本文研究之主要議題。 本文與過去文獻主要之差異為：(1) 資產模型依資產配置方式，使用蒙地卡羅模擬詳盡現金流路徑，著重於描述壽險業之情境；(2) 股票型風險性資產加入跳躍過程 (Jump) 與隨機波動兩種情境，以表達壽險業資產端承受資本市場變動加劇之風險；(3) 考慮政府監理寬容措施，以描述主管機關對於壽險業監理態度。 依蒙地卡羅模擬法試算保險安定基金公平費率，研究結果發現：(1)監理寬容期限增加時，安定基金公平費率增加；(2)監理標準提高，安定基金公平費率有先降後升之效果；(3)保險公司財務槓桿比例增加時，安定基金公平費率上升。 / Due to the global financial crisis in 2008 that resulted in systematic risks in the equity and credit market, it creates significant deprecation in the life insurers’ balance sheet which affect insurers’ solvency. In order to retain prudent supervision and market stability, the authority has announced capital temporal relief plan that may make insolvency insurer worse. Recent occurrences of financial distress to some insurers have raised questions about whether the current guaranty system that charge a flat levy rate in premium-based is adequate to protect policyholders. A risk-weighted levy rate in reserve-based has been proposed to establish reasonable contribution method which can avoid high risk insurers’ moral hazard and protect the other insurers from further systematic risks. A brief summary of the advantages of this paper is listed below：(1) By Monte Carol simulation method, detailed cash flow of insurer’s asset allocation can be used to describe the risk preference of life insurer. (2) Our stock model incorporates jump diffusion and stochastic volatility in order to reflect that life insurers face increasing volatility in capital market. (3) Consider regulatory forbearance to represent government’s attitude to life insurers. We calculate fair guaranty premium through Monte Carol simulation method. We find that： (1) Fair premium increases as extending the period of regulatory forbearance. (2) As regulatory criterion raises fair premium decreases at first, but increases if regulatory criterion reaches certain level. (3) Increasing leverage ratio of the insurer results in increasing fair premium.

The aim of this thesis is to estimate the volatility function of continuoustime stochastic models. The estimation of the volatility of the following wellknown international stock market indexes is presented as an application: Dow Jones Industrial Average, Standard and Poor’s 500, NIKKEI 225, CAC 40, DAX 30, FTSE 100 and IBEX 35. This estimation is studied from two different perspectives: a) assuming that the volatility of the stock market indexes displays shortrange dependence (SRD), and b) extending the previous model for processes with longrange dependence (LRD), intermediaterange dependence (IRD) or SRD. Under the efficient market hypothesis (EMH), the compatibility of the Vasicek, the CIR, the Anh and Gao, and the CKLS models with the stock market indexes is being tested. Nonparametric techniques are presented to test the affinity of these parametric volatility functions with the volatility observed from the data. Under the assumption of possible statistical patterns in the volatility process, a new estimation procedure based on the Whittle estimation is proposed. This procedure is theoretically and empirically proven. In addition, its application to the stock market indexes provides interesting results.

[pt] Historicamente, observa-se que as volatilidades de variáveis financeiras são drasticamente afetadas em períodos de crises econômicas. Em particular, essa observação é válida para a taxa de câmbio entre o Real e o Dólar norte-americano, o Índice Bovespa e o EMBI Brasil (Emerging Market Bond Índex+Brazil), usualmente utilizado como medida de Risco-País para a economia brasileira. Diante de tais evidências empíricas, a existência de um fator comum entre as volatilidades das três variáveis citadas torna-se uma suposição plausível. O presente trabalho propõe a extração deste fator latente, através da estimação por Quasi Máxima Verossimilhança de uma adaptação do modelo de volatilidade estocástica. A estimação é feita através da aplicação do filtro de Kalman em sua versão difusa, uma vez que se supõe que as volatilidades das variáveis em questão seguem processos não estacionários. A conclusão do trabalho apontou para a existência de um único fator comum às volatilidades mencionadas, corroborando as expectativas preliminares. / [en] Historically, financial variables’ volatilities are drastically affected during economical crisis periods. In particular, this statement is valid for the exchange rate between brazilian and north american currencies, the São Paulo Stock Exchange Index (Ibovespa) and the Emerging Market Bond Index + Brazil, usually interpreted as a measure of brazilian sovereign risk. Therefore, the presence of a common factor affecting the volatilities of these three variables becomes a plausible assumption. This work intends to extract this latent factor applying the quasi-maximum likelihood estimator into an adapted stochastic volatility model. The estimation requires the Kalman filtering on its diffuse version, once it’s supposed that the volatilities follow a non stationary process. The results indicated the presence of one common factor driving the mentioned volatilities, confirming the previous expectations.

Submitted by Ricardo Consonni (ricardo.consonni@gmail.com) on 2011-09-09T12:42:48Z No. of bitstreams: 1 +Dissetacao RC 2011 - v1g - Revisado.pdf: 2814391 bytes, checksum: f5888f2effddf979aa33bd15b87760d2 (MD5) / Approved for entry into archive by Gisele Isaura Hannickel (gisele.hannickel@fgv.br) on 2011-09-09T13:14:56Z (GMT) No. of bitstreams: 1 +Dissetacao RC 2011 - v1g - Revisado.pdf: 2814391 bytes, checksum: f5888f2effddf979aa33bd15b87760d2 (MD5) / Approved for entry into archive by Gisele Isaura Hannickel (gisele.hannickel@fgv.br) on 2011-09-09T13:15:04Z (GMT) No. of bitstreams: 1 +Dissetacao RC 2011 - v1g - Revisado.pdf: 2814391 bytes, checksum: f5888f2effddf979aa33bd15b87760d2 (MD5) / Made available in DSpace on 2011-09-09T13:17:32Z (GMT). No. of bitstreams: 1 +Dissetacao RC 2011 - v1g - Revisado.pdf: 2814391 bytes, checksum: f5888f2effddf979aa33bd15b87760d2 (MD5) Previous issue date: 2011-08-12 / Este trabalho apresenta um modelo para determinação da superfície de volatilidades de um par de moedas cujas opções têm baixa liquidez, utilizando superfícies de volatilidade com maior liquidez, de pares de moedas em que as moedas estudadas sejam uma de suas componentes. Esse objetivo é atingido através da utilização de um modelo de volatilidade estocástica. A calibração de seus parâmetros é feita a partir dos valores de mercado de Butterfly Spreads e Risk Reversals dos pares de moedas líquidos. O trabalho contribui em relação à literatura no sentido de ampliar a cobertura de strikes e vencimentos considerados, permitindo que, tanto opções pouco líquidas e fora do dinheiro, como notas estruturadas com opções embutidas possam ser mais adequadamente apreçadas. / This work presents a model for determining the volatility surface of a currency pair whose options have low liquidity, using higher liquidity volatility surfaces of other currency pairs, in which the desired currencies are one of their components. This goal is achieved through the use of a stochastic volatility model. The calibration of its parameters is done from market values of the Butterfly Spreads and Risk Reversals of the liquid-currency pairs. This work contributes to the literature in an effort to broaden the scope of strikes and maturities considered, allowing for both illiquid and out of-the-money options, as well as structured notes with embedded options, to be more appropriately priced.

Magister Scientiae - MSc / The present mini-thesis seeks to explore and investigate the mathematical theory and concepts that underpins the valuation of derivative securities, particularly European plainvanilla options. The main argument that we emphasise is that novel models of option pricing, as is suggested by Hull and White (1987) [1] and others, must account for the discrepancy observed on the implied volatility curve. To achieve this we also propose that market volatility be modeled as random or stochastic as opposed to certain standard option pricing models such as Black-Scholes, in which volatility is assumed to be constant. / South Africa

>Magister Scientiae - MSc / This dissertation studies the computation methods of pricing of Asian options. Asian options are options in which the underlying variable is the average price over a period of time. Because of this, Asian options have a lower volatility and this render them cheaper relative to their European counterparts. Asian options belong to the so-called path-dependent derivatives; they are among the most difficult to price and hedge both analytically and numerically. In practice, it is only discrete Asian options that are traded, however continuous Asian options are used for studying purposes. Several approaches have been proposed in the literature, including Monte Carlo simulations, tree-based methods, Taylor’s expansion, partial differential equations, and analytical ap- proximations among others. When using partial differential equations for pricing of continuous time Asian options, the high dimensionality is problematic. In this dissertation we focus on the discrete time methods. We start off by explaining the binomial tree method, and our last chapter presents the very exciting and relatively simple method of Tsao and Huang, using Taylor approximations. The main papers that are used in this dissertation are articles by Jan Vecer (2001); LCG Rogers (1995); Eric Benhamou (2001); Gianluca Fusai (2007); Kamizono, Kariya and Nakatsuma (2006) and Tsao and Huang (2007). The author has provided computations, including graphs and tables dispersed over the different chapters, to demonstrate the utility of the methods. We observe various parameters of influence such as correlation, volatility, strike, etc. A further contribution by the author of this dissertation is, in particular, in Chapter 5, in the presentation of the work of Tsao et al. Here we have provided slightly more detailed explanations and again some further computational tables.

In this masterthesis I have rewied basic approaches to volatility estimating. These approaches are based on classical and Bayesian statistics. I have applied the volatility models for the purpose of volatility forecasting of a different foreign exchange (EURUSD, GBPUSD and CZKEUR) in the different period (from a second period to a day period). I formulate the models EWMA, GARCH, EGARCH, IGARCH, GJRGARCH, jump diffuison with constant volatility and jump diffusion model with stochastic volatility. I also proposed an MCMC algorithm in order to estimate the Bayesian models. All the models we estimated as univariate models. I compared the models according to Mincer Zarnowitz regression. The most successfull model is the jump diffusion model with a stochastic volatility. On the second place they were the GJR- GARCH model and the jump diffusion model with a constant volatility. But the jump diffusion model with a constat volatilit provided much more overvalued results.The rest of the models were even worse. From the rest the IGARCH model is the best but provided undervalued results. All these findings correspond with R squared coefficient.

La première partie de cette thèse est consacrée aux méthodes numériques pour la simulation de processus aléatoires définis par des équations différentielles stochastiques (EDS). Nous commençons par l’étude de l’algorithme de Beskos et al. [13] qui permet de simuler exactement les trajectoires d’un processus solution d’une EDS en dimension 1. Nous en proposons une extension à des fins de calcul exact d’espérances et nous étudions l’application de ces idées à l’évaluation du prix d’options asiatiques dans le modèle de Black & Scholes. Nous nous intéressons ensuite aux schémas numériques. Dans le deuxième chapitre, nous proposons deux schémas de discrétisation pour une famille de modèles à volatilité stochastique et nous en étudions les propriétés de convergence. Le premier schéma est adapté à l’évaluation du prix d’options path-dependent et le deuxième aux options vanilles. Nous étudions également le cas particulier où le processus qui dirige la volatilité est un processus d’Ornstein-Uhlenbeck et nous exhibons un schéma de discrétisation qui possède de meilleures propriétés de convergence. Enfin, dans le troisième chapitre, il est question de la convergence faible trajectorielle du schéma d’Euler. Nous apportons un début de réponse en contrôlant la distance de Wasserstein entre les marginales du processus solution et du schéma d’Euler, uniformément en temps. La deuxième partie de la thèse porte sur la modélisation de la dépendance en finance et ce à travers deux problématiques distinctes : la modélisation jointe entre un indice boursier et les actions qui le composent et la gestion du risque de défaut dans les portefeuilles de crédit. Dans le quatrième chapitre, nous proposons un cadre de modélisation original dans lequel les volatilités de l’indice et de ses composantes sont reliées. Nous obtenons un modèle simplifié quand la taille de l’indice est grande, dans lequel l’indice suit un modèle à volatilité locale et les actions individuelles suivent un modèle à volatilité stochastique composé d’une partie intrinsèque et d’une partie commune dirigée par l’indice. Nous étudions la calibration de ces modèles et montrons qu’il est possible de se caler sur les prix d’options observés sur le marché, à la fois pour l’indice et pour les actions, ce qui constitue un avantage considérable. Enfin, dans le dernier chapitre de la thèse, nous développons un modèle à intensités permettant de modéliser simultanément, et de manière consistante, toutes les transitions de ratings qui surviennent dans un grand portefeuille de crédit. Afin de générer des niveaux de dépendance plus élevés, nous introduisons le modèle dynamic frailty dans lequel une variable dynamique inobservable agit de manière multiplicative sur les intensités de transitions. Notre approche est purement historique et nous étudions l’estimation par maximum de vraisemblance des paramètres de nos modèles sur la base de données de transitions de ratings passées / The first part of this thesis deals with probabilistic numerical methods for simulating the solution of a stochastic differential equation (SDE). We start with the algorithm of Beskos et al. [13] which allows exact simulation of the solution of a one dimensional SDE. We present an extension for the exact computation of expectations and we study the application of these techniques for the pricing of Asian options in the Black & Scholes model. Then, in the second chapter, we propose and study the convergence of two discretization schemes for a family of stochastic volatility models. The first one is well adapted for the pricing of vanilla options and the second one is efficient for the pricing of path-dependent options. We also study the particular case of an Orstein-Uhlenbeck process driving the volatility and we exhibit a third discretization scheme which has better convergence properties. Finally, in the third chapter, we tackle the trajectorial weak convergence of the Euler scheme by providing a simple proof for the estimation of the Wasserstein distance between the solution and its Euler scheme, uniformly in time. The second part of the thesis is dedicated to the modelling of dependence in finance through two examples : the joint modelling of an index together with its composing stocks and intensity-based credit portfolio models. In the forth chapter, we propose a new modelling framework in which the volatility of an index and the volatilities of its composing stocks are connected. When the number of stocks is large, we obtain a simplified model consisting of a local volatility model for the index and a stochastic volatility model for the stocks composed of an intrinsic part and a systemic part driven by the index. We study the calibration of these models and show that it is possible to fit the market prices of both the index and the stocks. Finally, in the last chapter of the thesis, we define an intensity-based credit portfolio model. In order to obtain stronger dependence levels between rating transitions, we extend it by introducing an unobservable random process (frailty) which acts multiplicatively on the intensities of the firms of the portfolio. Our approach is fully historical and we estimate the parameters of our model to past rating transitions using maximum likelihood techniques

Cette thèse porte sur l'estimation bayésienne d'état dans les séries temporelles modélisées à l'aide des variables latentes hybrides, c'est-à-dire dont la densité admet une composante discrète-finie et une composante continue. Des algorithmes généraux d'estimation des variables d'états dans les modèles de Markov partiellement observés à états hybrides sont proposés et comparés avec les méthodes de Monte-Carlo séquentielles sur un plan théorique et appliqué. Le résultat principal est que ces algorithmes permettent de réduire significativement le coût de calcul par rapport aux méthodes de Monte-Carlo séquentielles classiques / This thesis addresses the Bayesian estimation of hybrid-valued state variables in time series. The probability density function of a hybrid-valued random variable has a finite-discrete component and a continuous component. Diverse general algorithms for state estimation in partially observable Markov processesare introduced. These algorithms are compared with the sequential Monte-Carlo methods from a theoretical and a practical viewpoint. The main result is that the proposed methods require less processing time compared to the classic Monte-Carlo methods

This thesis is focused on the study of advanced methods of interest rate mo- dels calibration. The theoretical part provides introduction to basic terminology of financial mathematics, financial, concretely interest rate derivatives. It presents interest rate models, it is mainly aimed at HJM approach and describes in detail the Libor market model, then introduces the use of Bayesian principle in calcula- ting the probability of MCMC methods. At the end of this section the methods of calibration of volatility to market data are described. The last chapter consists of the practical application of different methods of calibration Libor market model and consequently pricing od interest rate swaption. The introduction describes procedure of arrangement of input data and process of pricing of interest rate derivatives. It is consequently used for the valuation of derivative contract accor- ding to mentioned methods. 1