MODELING SOVEREIGN RISKS: FROM A HYBRID MODEL TO THE GENERALIZED DENSITY APPROACH

Motivated by the European sovereign debt crisis, we propose a hybrid sovereign default model that combines an accessible part taking into account the evolution of the sovereign solvency and the impact of critical political events, and a totally inaccessible part for the idiosyncratic credit risk. We obtain closed‐form formulas for the probability that the default occurs at critical political dates in a Markovian setting. Moreover, we introduce a generalized density framework for the hybrid default time and deduce the compensator process of default. Finally, we apply the hybrid model and the generalized density to the valuation of sovereign bonds and explain the significant jumps in long‐term government bond yields during the sovereign crisis.     

Methodological Advances in DEA: A survey and an application for the Dutch electricity sector

We survey the methodological advances in DEA over the last 25 years and discuss the necessary conditions for a sound empirical application. We hope this survey will contribute to the further dissemination of DEA, the knowledge of its relative strengths and weaknesses, and the tools currently available for exploiting its full potential. Our main points are illustrated by the case of the DEA study used by the regulatory office of the Dutch electricity sector (Dienst Toezicht Elektriciteitswet; Dte) for setting price caps.     

A Dynamic Analysis of Fixed- and Adjustable-Rate Mortgage Terminations

This paper provides a side-by-side comparison of loan-level statistical models for fixed- and adjustable-rate mortgages. Multinomial logit models for quarterly conditional probabilities of default and prepayment are estimated. We find that the estimated impacts of embedded option values for prepayment and default are generally quite similar across both FRM and ARM loans, providing additional empirical support for the basic predictions of the options theory. We also find that differences in estimates of conditional probabilities of prepayment and default associated with mortgage age, origination period, original LTV, and relative loan size, indicate the continued significance of these other economic and demographic factors for empirical models of mortgage terminations.     

Market Failures in Real-Time Metering

Policies to promote real-time metering (RTM) require more than showing benefits from more timely responses to variations in cost. They require positive externalities to imply that too few meters would be installed through private transactions. RTM presents no systematic externalities when utilities must serve peak period users, and may present negative externalities under some conditions. Positive externalities are likely when electricity is rationed through blackouts. RTM may or may not increase welfare when peak period wholesale markets are not competitive; a prohibition on RTM might be appropriate in such situations even if metering itself were costless.     

对远期外汇合约信用风险的监管

随着远期外汇合约近几年来在我国的逐步推行,外汇市场活跃的同时也增加了外汇交易的信用风险,。要实现外汇市场的有序开放和稳定发展,就必须对其实行有效的风险管理,这包括交易主体对信用风险的识别,处置和外部监管。     

DEFAULT RISK AND DIVERSIFICATION: THEORY AND EMPIRICAL IMPLICATIONS

Recent advances in the theory of credit risk allow the use of standard term structure machinery for default risk modeling and estimation. The empirical literature in this area often interprets the drift adjustments of the default intensity's diffusion state variables as the only default risk premium. We show that this interpretation implies a restriction on the form of possible default risk premia, which can be justified through exact and approximate notions of "diversifiable default risk." The equivalence between the empirical and martingale default intensities that follows from diversifiable default risk greatly facilitates the pricing and management of credit risk. We emphasize that this is not an equivalence in distribution, and illustrate its importance using credit spread dynamics estimated in Duffee (1999) . We also argue that the assumption of diversifiability is implicitly used in certain existing models of mortgage-backed securities.     

用违约距离判别信用风险:一个实证研究

本文选取了在中国A股市场上市的4家具有一定代表性的ST公司和4家对照公司，并通过计算从2003年到2005年的静态违约距离和不变增长率假设下的违约距离，发现后者比前者具有更好的判别能力；同时对影响违约距离大小的输入变量进行了敏感性分析，发现违约距离对股票收益波动率的变化最为敏感，因而精确计算波动率是关键。     

违约损失率问题初探

巴塞尔新资本协议强调内部评级法在风险管理和资本监管中的重要作用。内部评级法的关键在于对违约率及其相关因素的测量,其中违约概率(PD)和违约损失率(LGD)是内部评级法的核心变量。对国际上关于LGD的表现及影响因素的讨论进行了总结与分析,并重点对LGD与PD之间的关系进行了介绍。