Man Po Kong = 信貸相聯票據和住宅按揭的預期損失之估值 / 文普綱. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 85-86). / Text in English; abstracts in English and Chinese. / Man Po Kong = Xin dai xiang lian piao ju he zhu zhai an jie de yu qi sun shi zhi gu zhi / Wen Pugang. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- The Structural model --- p.3 / Chapter 2.1 --- Merton's model --- p.3 / Chapter 2.2 --- The term structure of interest rate --- p.7 / Chapter 2.3 --- The default-triggering mechanism and derivations from strict priority rule --- p.9 / Chapter 2.4 --- Stationary leverage ratio --- p.11 / Chapter 2.5 --- The three-factor structural model --- p.12 / Chapter 3 --- Credit-linked Notes with early default risk --- p.18 / Chapter 3.1 --- Introduction to credit-linked notes --- p.18 / Chapter 3.2 --- The pricing of credit-linked notes --- p.20 / Chapter 3.3 --- Non mean-reverting leverage ratios --- p.21 / Chapter 3.3.1 --- Special case (pQv=0) --- p.23 / Chapter 3.4 --- Mean reverting leverage ratios --- p.25 / Chapter 4 --- Numerical results and discussion --- p.28 / Chapter 4.1 --- Exact solution (KQ=kv=PQv=PVr=0) --- p.31 / Chapter 4.2 --- "Lower bound approximation (kQ,kv≠0,pQr,pvr≠0)" --- p.37 / Chapter 4.2.1 --- Effect of interest rate --- p.43 / Chapter 4.3 --- Monte Carlo simulation (PQV≠0) --- p.47 / Chapter 5 --- Expected loss of residential mortgage loans --- p.56 / Chapter 5.1 --- Introduction to residential mortgage loans --- p.56 / Chapter 5.2 --- Calculation of expected loss of residential mortgage loans --- p.59 / Chapter 6 --- Numerical results and discussion --- p.65 / Chapter 6.1 --- Numerical results --- p.65 / Chapter 7 --- Conclusion --- p.73 / Chapter A --- Methodology --- p.75 / Chapter A.1 --- Monte Carlo Simulation --- p.76 / Chapter A.2 --- Finding lower and upper bound approach --- p.79 / Chapter A.2.1 --- Single stage approximation --- p.79 / Chapter A.2.2 --- Multistage lower bound approximation --- p.82 / Bibliography --- p.85

Yeung Kin Bong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 69-73). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Credit risk modeling --- p.3 / Chapter 1.2 --- Uniqueness of bi-directional: hybrid system --- p.4 / Chapter 1.3 --- Scope of the study --- p.5 / Chapter 2 --- Literature Review --- p.6 / Chapter 2.1 --- Statistical / Empirical approach --- p.6 / Chapter 2.2 --- Structural approach --- p.8 / Chapter 3 --- Background --- p.10 / Chapter 3.1 --- Merton structural default model --- p.10 / Chapter 3.2 --- Cross-sectional regression analysis (CRA) --- p.15 / Chapter 3.3 --- Neural network learning (NN) --- p.16 / Chapter 3.3.1 --- Single-layer network --- p.17 / Chapter 3.3.2 --- Multi-layer perceptron (MLP) --- p.20 / Chapter 3.3.3 --- Back-propagation network --- p.22 / Chapter 3.3.4 --- "Supervised, unsupervised and combine unsupervised-supervised learning" --- p.23 / Chapter 3.4 --- Weaknesses of uni-directional modeling --- p.23 / Chapter 4 --- Methodology --- p.26 / Chapter 4.1 --- Bi-directional modeling --- p.26 / Chapter 4.2 --- Asset price estimation --- p.31 / Chapter 4.3 --- Quantifying accounting data noise --- p.33 / Chapter 5 --- Proposed Model --- p.37 / Chapter 5.1 --- Core of the model --- p.37 / Chapter 5.2 --- Feature selection --- p.41 / Chapter 5.3 --- Bi-directional default neural system --- p.44 / Chapter 6 --- Implementations --- p.49 / Chapter 6.1 --- Data preparation --- p.50 / Chapter 6.2 --- Experiment --- p.51 / Chapter 6.3 --- Empirical results --- p.61 / Chapter 6.3.1 --- Predicted spreads from the uni-directional models --- p.61 / Chapter 6.3.2 --- Predicted spreads from the proposed bi-directional model --- p.63 / Chapter 6.3.3 --- Performance comparison --- p.64 / Chapter 7 --- Conclusions --- p.67 / Bibliography --- p.69

有實證研究表明，傳統的信貸風險結構模型顯著低估了違約概率以及信貸收益率差。傳統的結構模型有三個可能的問題：1. 因為正態假設，布朗模型在模擬公司資產價值的過程中未能捕捉到極端事件2. 市場微觀結構噪聲扭曲了股票價格所包含信息3. 在到期日前任何時間，標準BS 期權理論方法不足以描述任何破產的可能性。這些問題在過去的文獻中曾分別提及。而在本文中，在不同的信用風險結構模型的基礎上，我們提出了貝葉斯方法去估算公司價值的跳躍擴散過程和微觀結構噪聲。因為企業的資產淨值不能在市場上觀察，本文建議的貝葉斯方法可對隱藏變量和泊松衝擊作出一定的估算，並就後驗分佈進行財務分析。我們應用馬爾可夫鏈蒙特卡羅方法（MCMC）和吉布斯採樣計算每個參數的後驗分佈。以上的做法，允許我們檢查結構性信用風險模型的偏差主要是來自公司價值的分佈、期權理論方法或市場微觀結構噪聲。我們進行模擬研究以確定模型的表現。最後，我們以新興市場的數據實踐我們的模型。 / There is empirical evidence that structural models of credit risk significantly underestimate both the probability of default and credit yield spreads. There are three potential sources of the problems in traditional structural models. First, the Brownian model driving the firm asset value process may fail to capture extreme events because of the normality assumption. Second, the market micro-structure noise in trading may distort the information contained in equity prices within the estimation process. Third, the standard Black and Scholes option-theoretic approach may be inadequate to describe the consequences of bankruptcy at any time before maturity. These potential problems have been handled separately in the literature. In this paper, we propose a Bayesian approach to simultaneously estimate the jump-diffusion firm value process and micro-structure noise from equity prices based on different structural credit risk models. As the firm asset value is not observable but the equity price is, the proposed Bayesian approach is useful in the estimation with hidden variable and Poisson shocks, and produces posterior distributions for financial analysis. We demonstrate the application using the Markov chain Monte Carlo (MCMC) method to obtain the posterior distributions of parameters and latent variable. The proposed approach enables us to check whether the bias of the structural credit risk model is mainly caused by the firm value distribution, the option-theoretic method or the micro-structure noise of the market. A simulation study is conducted to ascertain the performance of our model. We also apply our model to the emerging market data. / Detailed summary in vernacular field only. / Chan, Sau Lung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 62-65). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / List of Tables --- p.vii / List of Figures --- p.viii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background and Intuition --- p.5 / Chapter 2.1 --- Merton Model with Trading Noise --- p.7 / Chapter 2.2 --- Black-Cox Model with Default Barrier --- p.10 / Chapter 2.3 --- Double Exponential Jump Diffusion Model (KJD Model) --- p.11 / Chapter 2.4 --- Equity Value via Laplace Transforms --- p.13 / Chapter 2.5 --- KJD Model with Trading Noises --- p.15 / Chapter 3 --- Bayesian Analysis --- p.17 / Chapter 3.1 --- Gibbs Sampling and Metropolis-Hastings Method --- p.17 / Chapter 3.2 --- Merton Model with Trading Noises (M1) --- p.19 / Chapter 3.2.1 --- Prior Distribution for M1 --- p.19 / Chapter 3.2.2 --- Posterior Distribution for M1 --- p.20 / Chapter 3.3 --- Merton Model with Default Barrier (M2) --- p.22 / Chapter 3.3.1 --- Prior Distribution for M2 --- p.23 / Chapter 3.3.2 --- Posterior Distribution for M2 --- p.23 / Chapter 3.4 --- KJD Model with Trading Noises (M3) --- p.25 / Chapter 3.4.1 --- Prior Distribution for M3 --- p.26 / Chapter 3.4.2 --- Posterior Distribution for M3 --- p.27 / Chapter 3.5 --- KJD Model with Default Barrier (M4) --- p.33 / Chapter 3.5.1 --- Prior Distribution for M4 --- p.34 / Chapter 3.5.2 --- Posterior Distribution for M4 --- p.35 / Chapter 4 --- Numerical Examples --- p.42 / Chapter 4.1 --- Simulation Analysis --- p.42 / Chapter 4.2 --- Empirical Study --- p.46 / Chapter 4.2.1 --- BEA and DBS, 2003-2004 --- p.46 / Chapter 4.2.2 --- HSBC, 2008-2009 --- p.49 / Chapter 5 --- Conclusion --- p.60 / Bibliography --- p.62

Tang Hoi-man = 受抵押品保護的公司債券的估值 / 鄧凱文. / Thesis submitted in: December 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 69-72). / Text in English; abstracts in English and Chinese. / Tang Hoi-man = Shou di ya pin bao hu de gong si zhai quan de gu zhi / Deng Kaiwen. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Literature Review --- p.3 / Chapter 2.1 --- Review of Merton Model [24] --- p.4 / Chapter 2.1.1 --- Refinement of the Structural Model --- p.6 / Chapter 2.2 --- "Hui, Lo, Huang and Lee model" --- p.8 / Chapter 2.3 --- Recent models consider the PD-RR relationship --- p.11 / Chapter 2.3.1 --- Frye model --- p.11 / Chapter 2.3.2 --- Jokivuolle and Peura model --- p.12 / Chapter 3 --- The Valuation of Collateralized Corporate Bond --- p.13 / Chapter 3.1 --- The framework of the Model --- p.13 / Chapter 3.2 --- The Valuation of Collateralized Corporate Bond --- p.17 / Chapter 3.2.1 --- Derivation of Collateralized Corporate Bond --- p.18 / Chapter 3.2.2 --- "Relation between Proposed Model and Hui, Lo, Huang and Lee Model" --- p.22 / Chapter 4 --- The Study of the Closed-form Solution --- p.24 / Chapter 4.1 --- Applications --- p.24 / Chapter 4.1.1 --- Probabilities of Default --- p.25 / Chapter 4.1.2 --- Expected Loss-given-default --- p.26 / Chapter 4.2 --- Closed-form solution and Monte-Carlo Simulation --- p.29 / Chapter 4.2.1 --- Closed-form Solution --- p.29 / Chapter 4.2.2 --- Monte-Carlo Simulation --- p.31 / Chapter 4.2.3 --- Comparison between Closed-form Solution and Monte- carlo Simulation --- p.33 / Chapter 5 --- Data Analysis and Discussion --- p.38 / Chapter 5.1 --- Effects on ELGD of Different Parameters --- p.38 / Chapter 5.1.1 --- "Effect of Initial Collateral Value, S0" --- p.39 / Chapter 5.1.2 --- "Effect of Collateral's Volatility, σs" --- p.39 / Chapter 5.1.3 --- "Effect of Correlation between Firm's Leverage Ratio and Collateral, pLS" --- p.40 / Chapter 5.1.4 --- "Effect of residue recovery rate, δ" --- p.40 / Chapter 5.1.5 --- "Effect of Maturity, T" --- p.41 / Chapter 5.2 --- Initial Setting of Parameters --- p.42 / Chapter 5.3 --- Effects on ELGD for Different Rated Firms --- p.43 / Chapter 5.3.1 --- Effects on ELGD of Different S0 and σs --- p.45 / Chapter 5.3.2 --- Effect on ELGD of Different S0 and pLS --- p.47 / Chapter 5.3.3 --- Effect on ELGD of Different S0 and δ --- p.49 / Chapter 5.3.4 --- Effect on ELGD of Different S0 and T --- p.51 / Chapter 5.3.5 --- Effect on ELGD of Different and pLS --- p.53 / Chapter 5.3.6 --- Effect on ELGD of Different σs and δ --- p.55 / Chapter 5.3.7 --- Effect on ELGD of Different and T --- p.57 / Chapter 5.3.8 --- Effect on ELGD of Different pLS and δ --- p.59 / Chapter 5.3.9 --- Effect on ELGD of Different pLS and T --- p.61 / Chapter 5.3.10 --- Effect of on ELGD Different 6 and T --- p.63 / Chapter 5.4 --- Summary --- p.65 / Chapter 6 --- Conclusion --- p.67 / Bibliography --- p.69 / Chapter A --- Derivation of Pricing Equation --- p.73

Credit risk is an important source of risk for almost all of the financial securities. The frequent and serious financial crisis has made credit risk a sensitive and crucial consideration for financial institutions, corporations, and individual investors. The accurate pricing for credit risk and credit risky assets depends crucially upon the credit risk term structure---it implies the market expectation for the future credit risk. However, the credit risk analysis is still in its very early stages of development. The investigation about the credit risk term structure, especially the empirical exploration, has many blank points. Earlier research on the credit risk term structure mainly concentrates on the slopes, pertaining to the simple linear term structure which is not applicable to the middle credit quality assets. Thus the curvature of the spread curves may infer snore information about the changes of future credit qualities, the credit cycles, and the recurring business cycles. In this thesis, a bond pair approach is developed to study the shape (curvature as well as slope) of individual spread curves, and the relationship among spread curves for bonds with different ratings. We uncover downward sloping spread curves for triple C and double C bonds and upward sloping spread curves for triple A+ and triple A bonds. We also uncover hump-shaped spread curves for middle-graded bonds including double A to single B, and there exist peak points on these spread curves. We document the relationship among spread curves for bonds with different ratings In terms of time to peak and peak spread. We conclude that, in comparing higher rated bonds (say, double A) with lower rated bonds (say, single B), the credit spread is higher and time to peak is shorter for the latter than the former. In particular, these hump-shaped curves are bounded from above by downward sloping spread curves for triple C and double C bonds and bounded from below by upward sloping spread curves for triple A+ and triple A bonds. These findings provide a good explanation for the middle-rated bonds' spread curves. This evidence helps us to better understand the credit risk term structure, to accurately price credit risk and credit risky assets, and to appropriately manage credit risk. / Hu Wen-wei. / "August 2000." / Adviser: Jia He. / Source: Dissertation Abstracts International, Volume: 61-08, Section: A, page: 3284. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 93-111). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest dissertations and theses, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Huang Ming Xi = 三因結構模型之公司債劵定價及其應用 / 黃銘浠. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 99-102). / Text in English; abstracts in English and Chinese. / Huang Ming Xi = San yin jie gou mo xing zhi gong si zhai quan ding jia ji qi ying yong / Huang Mingxi. / Abstract --- p.i / Acknowledgements --- p.iii / Contents --- p.iv / List of Figures --- p.vii / List of Tables --- p.xiii / Chapter Chapter 1. --- Introduction --- p.1 / Chapter Chapter 2. --- Structural Models of Credit Pricing --- p.3 / Chapter 2.1 --- Introduction --- p.3 / Chapter 2.2 --- Merton's Model (1974) --- p.4 / Chapter 2.2.1 --- The Framework of the Traditional Contingent Claims Analysis (CCA) --- p.5 / Chapter 2.2.2 --- The Valuation of Corporate Bonds with B-S Option Pric- ing Theory --- p.9 / Chapter 2.2.3 --- The Limitations of Traditional Contingent Claim Ap- proach --- p.12 / Chapter 2.3 --- "Shimko, Tejima and Deventer (1993)" --- p.15 / Chapter 2.3.1 --- The Merton's Model in a Stochastic Interest Rate Frame- work --- p.15 / Chapter 2.4 --- Longstaff and Schwartz (1995) --- p.17 / Chapter 2.4.1 --- A Structure Model of Early Default Mechanism and De- viations from APR --- p.17 / Chapter 2.5 --- Briys and de Varenne (1997) --- p.21 / Chapter 2.5.1 --- A Structure Model of Stochastic Default Barrier --- p.21 / Chapter 2.5.2 --- The Valuation of Risky Zero-Coupon Bonds --- p.22 / Chapter 2.6 --- Stationary-leverage-ratio Models --- p.25 / Chapter 2.6.1 --- Tauren (1999) --- p.25 / Chapter 2.6.2 --- Collin-Dufresne and Goldstein (2001) --- p.27 / Chapter 2.7 --- Summary --- p.29 / Chapter Chapter 3. --- The Valuation Framework of the Three-factor Model --- p.32 / Chapter 3.1 --- Introduction --- p.33 / Chapter 3.2 --- The Framework of the Three-factor Model --- p.35 / Chapter 3.3 --- The Valuation of Risky Bonds --- p.39 / Chapter 3.3.1 --- Imposing an Early Default Mechanism --- p.42 / Chapter 3.3.2 --- Application: The Valuation of Probability of Default --- p.45 / Chapter Chapter 4. --- The Pricing Methodology of the Three-factor Model --- p.46 / Chapter 4.1 --- Simplification of the Problem --- p.47 / Chapter 4.2 --- Methodology of Upper-lower Bound Scheme --- p.48 / Chapter 4.2.1 --- Single-stage Approximation --- p.48 / Chapter 4.2.2 --- Illustrative Examples --- p.53 / Chapter 4.2.3 --- Multistage Approximation --- p.54 / Chapter 4.2.4 --- Summary --- p.58 / Chapter 4.2.5 --- Systematic Multistage Estimation of Bond Price --- p.61 / Chapter 4.3 --- Estimation of Default Probability --- p.63 / Chapter Chapter 5. --- Numerical Results and Discussion --- p.69 / Chapter 5.1 --- Initial Setting of Parameters --- p.69 / Chapter 5.2 --- Numerical Results and Discussion --- p.74 / Chapter Chapter 6. --- Conclusion --- p.89 / Appendix A. The Derivation of the Three-Factor Model --- p.91 / Bibliography --- p.99

Lam, Ho Man. / "August 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 42-43). / Abstracts in English and Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Levy Process --- p.5 / Chapter 2.1 --- Merton's Jump-Diffusion model (1976) --- p.8 / Chapter 2.2 --- Estimation of Levy processes --- p.9 / Chapter 3 --- Transform Martingale Estimation --- p.11 / Chapter 3.1 --- Maximum Likelihood Estimation --- p.11 / Chapter 3.2 --- Transform Martingale Estimating Functions --- p.13 / Chapter 3.2.1 --- Transform Quasi-Score Function --- p.15 / Chapter 3.2.2 --- Composite Quasi-Score Function --- p.17 / Chapter 3.2.3 --- Implementation Issue --- p.18 / Chapter 3.2.4 --- Transform Martingale Estimation on Levy process --- p.21 / Chapter 4 --- Structural Models of Credit Risk --- p.22 / Chapter 4.1 --- Overview --- p.22 / Chapter 4.2 --- Merton's structural credit risk model (1974) --- p.23 / Chapter 4.3 --- Estimation Methodologies --- p.24 / Chapter 4.4 --- Martingale Estimation with KMV's Method --- p.26 / Chapter 5 --- Simulation Study --- p.28 / Chapter 5.1 --- Equity Estimation --- p.28 / Chapter 5.2 --- Estimation of Structural Models --- p.37 / Chapter 6 --- Conclusion --- p.41 / Bibliography --- p.42

In this thesis, efforts are devoted to the stochastic modeling, measurement and evaluation of credit risks, the development of mathematical and statistical tools to estimate and predict these risks, and methods for solving the significant computational problems arising in this context. The reduced-form intensity based credit risk models are studied. A new type of reduced-form intensity-based model is introduced, which can incorporate the impacts of both observable trigger events and economic environment on corporate defaults. The key idea of the model is to augment a Cox process with trigger events. In addition, this thesis focuses on the relationship between structural firm value model and reduced-form intensity based model. A continuous time structural asset value model for the asset value of two correlated firms with a two-dimensional Brownian motion is studied. With the incomplete information introduced, the information set available to the market participants includes the default time of each firm and the periodic asset value reports. The original structural model is first transformed into a reduced-form model. Then the conditional distribution of the default time as well as the asset value of each name are derived. The existence of the intensity processes of default times is proven and explicit form of intensity processes is given in this thesis. Discrete-time Markovian models in credit crisis are considered. Markovian models are proposed to capture the default correlation in a multi-sector economy. The main idea is to describe the infection (defaults) in various sectors by using an epidemic model. Green’s model, an epidemic model, is applied to characterize the infectious effect in each sector and dependence structures among various sectors are also proposed. The models are then applied to the computation of Crisis Value-at-Risk (CVaR) and Crisis Expected Shortfall (CES). The relationship between correlated defaults of different industrial sectors and business cycles as well as the impacts of business cycles on modeling and predicting correlated defaults is investigated using the Probabilistic Boolean Network (PBN). The idea is to model the credit default process by a PBN and the network structure can be inferred by using Markov chain theory and real-world data. A reduced-form model for economic and recorded default times is proposed and the probability distributions of these two default times are derived. The numerical study on the difference between these two shows that our proposed model can both capture the features and fit the empirical data. A simple and efficient method, based on the ordered default rate, is derived to compute the ordered default time distributions in both the homogeneous case and the two-group heterogeneous case under the interacting intensity default contagion model. Analytical expressions for the ordered default time distributions with recursive formulas for the coefficients are given, which makes the calculation fast and efficient in finding rates of basket CDSs. / published_or_final_version / Mathematics / Doctoral / Doctor of Philosophy