IRB法下公司敞口组合的风险驱动因子计量研究

巴塞尔银行监管委员会针对防范信贷组合信用风险所需要的资本制定的内部评级法,通过风险驱动因子的变化来反映组合回报的变化,并根据风险权重函数,通过风险加权资产转化为与每一项信用风险敞口更准确匹配的资本要求.本文对违约概率、违约损失率、违约敞口、期限因素以及违约相关性等信贷组合信用风险的风险驱动因子的度量进行了综合研究.     

中国市政债券信用风险与发债规模研究

本文首先参考美国发行市政债券的概况提出了市政债券违约风险的概念 ;随后利用KMV模型建立了市政债券信用风险模型 ,提出了计算理论违约概率的方法 ;然后利用北京与上海的财政收支数据分析不同发债规模下的信用风险 ,得出理论违约概率 ;为了更接近实际情况又提出了财政收入真实分布的概念 ,计算出基于真实分布的不同债务规模下的违约概率 ,并将信用风险与发债规模相联系 ,提出合理的发债规模。由此形成的市政债券信用风险的模型方法 。     

债券违约对流动性影响的传染效应研究

2014年以来我国信用债市场违约事件频发,信用风险的积聚可能引发债券市场流动性恶化。本文以2014―2019年交易所和银行间市场信用债为研究对象,实证考察违约事件对债券流动性影响的传染效应。研究发现:违约事件在同一发行主体的债券之间具有流动性传染效应,当公司的某期债券出现违约时,公司其他未到期债券的流动性水平显著下降;违约事件对同行业其他公司债券的流动性具有传染效应,当行业中出现债券违约事件时,行业内其他公司的债券流动性显著降低;违约事件爆发越密集或者违约事件越严重,对债券流动性的负面影响越大,而且民营企业债受到的影响要大于国有企业债,低信用等级债受到的影响要大于高信用等级债;在市场密集爆发违约事件或出现较为严重的违约事件时期,宏观流动性增加能够改善债券流动性。     

信用违约风险传染建模

在信用组合中,企业的违约是相互随机依赖的。除了来自宏观经济因素的影响,即因果传染;还有一种影响来自于企业间的直接相互关系,我们称其为信用违约传染。在目前,席卷全球的次贷风暴,就是一个信用风险传染的实例。到目前为止,人们尝试了从不同角度为违约传染建模,特别是从简约模型角度出发。本文从结构模型角度出发,为信用违约传染建模。并在此模型基础上,分析其对信用衍生品定价的影响。     

以内部评级法改进信用风险限额管理

信用风险限额管理的基本涵义一般而言,信用风险由违约风险、清偿风险和头寸风险三部分组成。违约风险通常用违约概率(PD)度量;清偿风险是清偿率(RecoveryRate)不足以弥补银行的风险暴露所造成风险,用违约损失率(LGD)度量;头寸风险指暴露在信用风险下头寸大小的不确定性,用违约风险暴露(EAD)度量。信用风险限额是商业银行根据风险和收益相匹配的原则,采用一定的标准和方法,确定其可以承受的信用风险敞口上限,即其可接受的违约风险暴露上限。信用风险限额管理是指商业银行对信用风险限额进行分配、监测、预警和控制的全过程管理。通常,商…     

企业债券违约对区域信用环境的影响——来自债券一级市场的证据北大核心

近年来,我国债券市场违约事件频发,违约数量逐年攀升,违约金额不断扩大。债券违约不仅对违约企业自身产生影响,还会对区域整体信用环境造成冲击。选取2014—2021年中国债券市场违约情况和债券发行定价信息,对债券违约引发的信用风险在地区内的传染效应进行研究。结果发现债券违约事件会显著提高地区内企业债券发行的风险溢价水平,且随着违约金额的增大、违约次数的增多,公司发债定价水平也相应提高,并且违约企业中国有企业占比也与债券发行定价正相关。为此,建议监管部门加快完善违约债券处置生态体系,地方政府切实担负起处置金融风险的属地责任,企业应更加科学地制定债务融资计划和发展战略,着力防范企业债券违约风险在地区内传导,实现区域经济的高质量发展。     

甘肃商业银行信用风险的研究

本文利用改进的KMV模型,对甘肃省11家上市公司2010年中期财务数据进行分析,得到各个上市公司的违约距离和违约概率,比较了各公司的信用状况,得出甘肃省商业银行信用风险总体较低的结论,最后提出了控制研究甘肃省商业银行信用风险的几点建议。     

甘肃商业银行信用风险的研究

本文利用改进的KMV模型,对甘肃省11家上市公司2010年中期财务数据进行分析,得到各个上市公司的违约距离和违约概率,比较了各公司的信用状况,得出甘肃省商业银行信用风险总体较低的结论,最后提出了控制研究甘肃省商业银行信用风险的几点建议。     

企业债券风险估值与简化式方法

信用风险、利率风险和流动性风险是债券投资者面临的最严峻的风险,对这几种风险的精确估计是债券定价的合理依据和债券投资者有效风险管理的前提.本文介绍一种风险估值的模型--简化式方法,并探讨它在债券定价、信用风险、流动性风险以及违约损失率估计中的应用.     

“违约潮”背景下上市公司信用风险分析——以河北省为例

2018年以来的债券违约潮中出现很多上市公司发行的债券违约。通过对河北省58家上市公司的信用风险状况进行评估。结果表明,大部分上市公司的预期违约率不超过40%,属于房地产、电力、机械、建材等周期性行业的上市公司的信用风险较高,国有企业的平均预期违约率高于民营企业。因此,应关注预期违约率最高的房地产企业和地方国有企业,同时采取措施避免金融去杠杆对民营企业融资造成不利影响。     

The term structure of credit spreads with jump risk

Default risk analysis is important for valuing corporate bonds, swaps, and credit derivatives and plays a critical role in managing the credit risk of bank loan portfolios. This paper offers a theory to explain the observed empirical regularities on default probabilities, recovery rates, and credit spreads. It incorporates jump risk into the default process. With the jump risk, a firm can default instantaneously because of a sudden drop in its value. As a result, a credit model with the jump risk is able to match the size of credit spreads on corporate bonds and can generate various shapes of yield spread curves and marginal default rate curves, including upward-sloping, downward-sloping, flat, and hump-shaped, even if the firm is currently in a good financial standing. The model also links recovery rates to the firm value at default so that the variation in recovery rates is endogenously generated and the correlation between recovery rates and credit ratings before default reported in Altman [J. Finance 44 (1989) 909] can be justified.     

Empirical credit cycles and capital buffer formation

We model 1927–1997 US business failure rates using an unobserved components time series model. Clear evidence is found of cyclical behavior in default rates. We also detect significant longer term movements in default rates and default correlations. In a multi-year backtest experiment we show that accommodation of default rate dynamics has important consequences for credit risk capitalization requirements. Static or myopic variants of credit portfolio models miss significant periods of credit risk accumulation. Empirically congruent dynamic models by contrast provide more timely warning signals of credit risk build-up. In this way they may mitigate some of the pro-cyclicality concerns.     

From equity to default correlation with taxes

For fixed income investment, the preponderant risk is the clustering of defaults in the portfolio. Accurate prediction of such clustering depends on the knowledge of default correlation. We develop models with exogenous debt and endogenous debt to predict default correlations from equity correlations based on a self-consistent structural framework. We also examine how taxes affect the prediction of default correlations based on the two models. The empirical analysis shows that the corporate taxes tend to decrease default correlations, while personal taxes could increase or decrease default correlations. Our default correlation model with exogenous debt does a better job of predicting default correlations for high quality bonds, while the one with endogenous debt predicts more accurately for lower rated bonds. Our studies not only theoretically improve the modeling of default correlation in the structural setting but also shed new light on various aspects of default correlations and thereby help financial practitioners price credit derivatives more accurately and formulate more effective strategies to manage default risk of credit portfolios.     

A first-passage-time model under regime-switching market environment

In this paper, we suggest a first-passage-time model which can explain default probability and default correlation dynamics under stochastic market environment. We add a Markov regime-switching market condition to the first-passage-time model of Zhou [Zhou, C., 2001. An analysis of default correlations and multiple defaults. Review of Financial Studies 14, 555–576]. Using this model, we try to explain various relationship between default probability, default correlation, and market condition. We also suggest a valuation method for credit default swap (CDS) with (or without) counterparty default risk (CDR) and basket default swap under this model.Our numerical results provide us with several meaningful implications. First, default swap spread is higher in economic recession than in economic expansion across default swap maturity. Second, as the difference of asset return volatility between under bear market and under bull market increases, CDS spread increases regardless of maturity. Third, the bigger the intensity shifting from bull market to bear market, the higher the spread for both CDS without CDR and basket default swap.     

A Simple Approach to Valuing Risky Fixed and Floating Rate Debt

We develop a simple approach to valuing risky corporate debt that incorporates both default and interest rate risk. We use this approach to derive simple closed-form valuation expressions for fixed and floating rate debt. The model provides a number of interesting new insights about pricing and hedging corporate debt securities. For example, we find that the correlation between default risk and the interest rate has a significant effect on the properties of the credit spread. Using Moody's corporate bond yield data, we find that credit spreads are negatively related to interest rates and that durations of risky bonds depend on the correlation with interest rates. This empirical evidence is consistent with the implications of the valuation model.     

Sovereign defaults by currency denomination

This paper explores the drivers of sovereign default in 100 countries over the period 1996–2012. We build a new data set of sovereign defaults and find that default events for local and foreign currency bonds are equally likely. However, governments default under different economic and financial conditions depending on the currency in which bonds are issued. The explained variation in default probability rises from 43% to 62% when we account for differences in currency denomination. We also provide evidence that global factors and market sentiment, which are known to drive sovereign spreads, do not help explain the probability of sovereign default. Hence, these factors appear to affect the price of sovereign credit risk, although not the risk itself.     

基于KMV模型的上市中小企业信贷风险研究

本文利用改进的KMV模型,对我国上市中小企业2008-2011年的信贷风险进行实证分析,并对改进后的模型进行准确性研究。研究结果表明:上市中小企业资产规模对违约距离的影响具有不确定性,但效果也不明显;股价的波动也会影响到违约距离的大小,且两者的关系是负相关的。改进后的KMV模型计算出的违约距离能很好地对上市中小企业的信贷风险进行度量和判别,实证分析表明:上市中小企业的违约距离近年来呈下降趋势,信贷风险有增大的迹象。     

The analytic pricing of asymmetric defaultable swaps

Swaps where both parties are exposed to credit risk still lack convincing pricing mechanisms. This article presents a reduced-form model where the event of default is related to structural characteristics of each party. The cash flows submitted to credit risk are identified before the swap is priced. Analytical pricing formulas for interest rate and currency swaps are computed using a Gaussian model for risky bonds. Currency swaps exhibit additional correlation risk. The benefits from netting depend on the balance between exposures and market conditions in valuation. We show that sources of credit risk asymmetries are also likely to impact on credit spreads.     

Credit Derivatives and the Default Risk of Large Complex Financial Institutions

This paper proposes and implements a multivariate model of the coevolution of the first and second moments of two broad credit default swap indices and the equity prices of sixteen large complex financial institutions. We use this empirical model to build a bank default risk model, in the vein of the classic Merton-type, which utilises a multi-equation framework to model forward-looking measures of market and credit risk using the credit default swap (CDS) index market as a measure of the conditions of the global credit environment. In the first step, we estimate the dynamic correlations and volatilities describing the evolution of the CDS indices and the banks’ equity prices and then impute the implied assets and their volatilities conditional on the evolution and volatility of equity. In the second step, we show that there is a substantial ‘asset shortfall’ and that substantial capital injections and/or asset insurance are required to restore the stability of our sample institutions to an acceptable level following large shocks to the aggregate level of credit risk in financial markets.     

Modelling bonds and credit default swaps using a structural model with contagion

This paper develops a two-dimensional structural framework for valuing credit default swaps and corporate bonds in the presence of default contagion. Modelling the values of related firms as correlated geometric Brownian motions with exponential default barriers, analytical formulae are obtained for both credit default swap spreads and corporate bond yields. The credit dependence structure is influenced by both a longer-term correlation structure as well as by the possibility of default contagion. In this way, the model is able to generate a diverse range of shapes for the term structure of credit spreads using realistic values for input parameters.