Counter‐Credit‐Risk Yield Spreads: A Puzzle in China's Corporate Bond Market

In this paper, using China's risk‐free and corporate zero yields together with aggregate credit risk measures and various control variables from 2006 to 2013, we document a puzzle of counter‐credit‐risk corporate yield spreads. We interpret this puzzle as a symptom of the immaturity of China's credit bond market, which reveals a distorted pricing mechanism latent in the fundamental of this market. We also find interesting results about relationships between corporate yield spreads and interest rates and risk premia and the stock index, and these results are somewhat attributed to this puzzle.     

BOUNDING WRONG‐WAY RISK IN CVA CALCULATION

A credit valuation adjustment (CVA) is an adjustment applied to the value of a derivative contract or a portfolio of derivatives to account for counterparty credit risk. Measuring CVA requires combining models of market and credit risk to estimate a counterparty's risk of default together with the market value of exposure to the counterparty at default. Wrong‐way risk refers to the possibility that a counterparty's likelihood of default increases with the market value of the exposure. We develop a method for bounding wrong‐way risk, holding fixed marginal models for market and credit risk and varying the dependence between them. Given simulated paths of the two models, a linear program computes the worst‐case CVA. We analyze properties of the solution and prove convergence of the estimated bound as the number of paths increases. The worst case can be overly pessimistic, so we extend the procedure by constraining the deviation of the joint model from a baseline reference model. Measuring the deviation through relative entropy leads to a tractable convex optimization problem that can be solved through the iterative proportional fitting procedure. Here, too, we prove convergence of the resulting estimate of the penalized worst‐case CVA and the joint distribution that attains it. We consider extensions with additional constraints and illustrate the method with examples.     

P2P网络借贷市场信用风险识别

近年来,P2P网络借贷市场成为我国金融领域的重灾区,各类问题层出不穷,不仅损害了投资者利益,而且严重扰乱了我国的金融秩序,深入研究P2P网络借贷市场存在的问题具有重要现实意义。P2P网络借贷市场是信息不对称最为严重的市场之一,对借款人信用风险进行识别是P2P网络借贷的关键环节。根据信用风险定价理论,借贷利率应该充分反映违约风险,通过检验借贷利率与违约风险之间的关系可以验证借贷市场信用风险识别机制的有效性。基于“人人贷”平台公开的历史交易数据对P2P网络借贷市场的信用风险识别问题进行实证研究,结果表明:借贷利率能部分反映借款人的信用风险,但在相同的利率水平下,其他指标与违约风险也存在显著性关系,表明相同的利率未对应相同的信用风险,平台的信用风险识别机制部分有效。进一步研究表明,在缺乏成熟、易用的个人征信产品的情况下,无论借款人、P2P平台,还是投资者,对信用风险影响因素的判断与实际情况都存在一定的偏差,工作经验丰富的借款人付出了过高的借贷成本,平台在判断收入对信用风险的影响方面出现了偏差,投资者则忽视了借款人学历的价值。建议打破个人征信数据壁垒,丰富个人征信产品,保护居民信用数据安全,以保障借贷市场的持续发展。     

TIME‐CHANGED MARKOV PROCESSES IN UNIFIED CREDIT‐EQUITY MODELING

This paper develops a novel class of hybrid credit‐equity models with state‐dependent jumps, local‐stochastic volatility, and default intensity based on time changes of Markov processes with killing. We model the defaultable stock price process as a time‐changed Markov diffusion process with state‐dependent local volatility and killing rate (default intensity). When the time change is a Lévy subordinator, the stock price process exhibits jumps with state‐dependent Lévy measure. When the time change is a time integral of an activity rate process, the stock price process has local‐stochastic volatility and default intensity. When the time change process is a Lévy subordinator in turn time changed with a time integral of an activity rate process, the stock price process has state‐dependent jumps, local‐stochastic volatility, and default intensity. We develop two analytical approaches to the pricing of credit and equity derivatives in this class of models. The two approaches are based on the Laplace transform inversion and the spectral expansion approach, respectively. If the resolvent (the Laplace transform of the transition semigroup) of the Markov process and the Laplace transform of the time change are both available in closed form, the expectation operator of the time‐changed process is expressed in closed form as a single integral in the complex plane. If the payoff is square integrable, the complex integral is further reduced to a spectral expansion. To illustrate our general framework, we time change the jump‐to‐default extended constant elasticity of variance model of Carr and Linetsky (2006) and obtain a rich class of analytically tractable models with jumps, local‐stochastic volatility, and default intensity. These models can be used to jointly price equity and credit derivatives.     

PRICING AND SEMIMARTINGALE REPRESENTATIONS OF VULNERABLE CONTINGENT CLAIMS IN REGIME‐SWITCHING MARKETS

Using a suitable change of probability measure, we obtain a Poisson series representation for the arbitrage‐free price process of vulnerable contingent claims in a regime‐switching market driven by an underlying continuous‐time Markov process. As a result of this representation, along with a short‐time asymptotic expansion of the claim's price process, we develop an efficient novel method for pricing claims whose payoffs may depend on the full path of the underlying Markov chain. The proposed approach is applied to price not only simple European claims such as defaultable bonds, but also a new type of path‐dependent claims that we term self‐decomposable, as well as the important class of vulnerable call and put options on a stock. We provide a detailed error analysis and illustrate the accuracy and computational complexity of our method on several market traded instruments, such as defaultable bond prices, barrier options, and vulnerable call options. Using again our Poisson series representation, we show differentiability in time of the predefault price function of European vulnerable claims, which enables us to rigorously deduce Feynman‐Ka? representations for the predefault pricing function and new semimartingale representations for the price process of the vulnerable claim under both risk‐neutral and objective probability measures.     

资产规模、融资路径与商业信用供给

现有文献就企业规模对企业商业信用供给有不同的研究结论,说明这一方面的研究还有待完善。本文结合数理模型和实证研究,分析不同企业规模下,融资路径不同对企业商业信用供给的影响。研究发现,我国中小企业在发展未达到一定规模之前,受市场竞争劣势影响,需要提供大量商业信用来维持市场生存和发展,而此时由于我国金融系统对中小企业的信贷歧视,获得银行信贷支持比较少,因此需要大量的商业信用融资来支持商业信用提供。随着商业信用融资的增加,融资成本提高,最终导致商业信用提供力度逐步下降。当企业发展超出一定规模后,银行信贷支持逐步增强,企业可以用银行信用替代成本更高的商业信用融资,导致商业信用融资逐步下降,同时也使得企业提供商业信用的能力上升。文章研究结论表明,商业信用提供与企业规模之间的关系不是简单的线性关系,而是一个二次函数关系。     

Multiple Ratings Model of Defaultable Term Structure

A new approach to modeling credit risk, to valuation of defaultable debt and to pricing of credit derivatives is developed. Our approach, based on the Heath, Jarrow, and Morton (1992) methodology, uses the available information about the credit spreads combined with the available information about the recovery rates to model the intensities of credit migrations between various credit ratings classes. This results in a conditionally Markovian model of credit risk. We then combine our model of credit risk with a model of interest rate risk in order to derive an arbitrage‐free model of defaultable bonds. As expected, the market price processes of interest rate risk and credit risk provide a natural connection between the actual and the martingale probabilities.     

搜寻成本与信誉租金对厂商定价的影响

信息的非对称性导致消费者在购物时要进行搜寻。搜寻是有代价的经济活动 ;在搜寻中花费的精力、人力、金钱、时间的机会成本构成搜寻成本。由于搜寻成本的存在消费者在购物时往往放弃搜寻 ,直接到信誉好的商店高价购物 ,以确保商品的效用。信誉度高而给产品定出高价从中获得的经济利润叫做信誉租金。搜寻成本与信誉租金存在因果关系。他们使厂商面临的需求曲线向下倾斜 ,使厂商给自己的产品定高价 ,长期均衡在经济利润上。     

上市公司提供商业信用的影响因素研究

我国企业在交易中采用赊销的比例低于欧美国家。以"应收账款/流动资产"作为商业信用水平的度量指标,对影响上市公司提供商业信用的因素进行研究发现:上市公司较少依赖提供商业信用来进行质量信号传递;拥有较高存货水平的上市公司为了减低存储成本、促进销售,会采用较为宽松的信用政策,从而导致应收账款的增加;在信用普遍缺失的环境下,对坏账损失的担忧抑制了企业主动通过提供商业信用为客户融资,进而来扩大或保护自己竞争优势的行为;在行业景气的情况下,对未来的乐观预期降低了经营者对坏账的担忧,进而倾向于采用较为宽松的信用政策,导致应收账款水平提高。     

农村信贷配给现状、成因及对策分析

目前,我国农村存在着严重的信贷配给不足现象,严重减低了农村经济主体贷款可获得性。造成这一现象的原因既有农村金融供给方面的原因,又有农村金融需求方面的原因,还有农村金融环境方面的原因,应从多方面着手探讨缓解农村信贷配给的路径。     

信贷周期理论研究综述

信贷周期是银行在内生和外生的机制或条件下行为集合所形成的一种信贷紧缩和信贷扩张的交替往复的现象。国外学术界对于信贷周期理论的探讨,可以分为三个角度：一是基于信息经济学理论,从信贷市场的不完全性和信息不对称角度阐述了经济波动的信贷观点;二是从银行信贷行为的角度,认为银行的行为具有内在的顺周期性,从而加剧了经济的波动;三是从银行业风险管理和监管的角度考察。     

消费品市场信用缺失的博弈分析

当前我国的整个市场特别是消费品市场存在着严重的信用缺失问题,对消费者的身心造成了极大的伤害.市场经济是信用经济,诚信原则是市场经济的灵魂和基础,重建消费品市场诚信环境,维护消费者权益是当务之急.信用是博弈的结果,从消费者与企业、企业与监管部门的博弈可以找到消费品市场信用缺失产生的原因.针对问题,可以对症下药,从根源上进行治理:建立高效的信息传输机制;完善法律体系,加大监督执法力度,建立高额赔偿金制度,让造假者付出高昂的成本;深化产权制度改革,使产权所有者具有进行重复博弈的动力,而着眼于长远利益.     

RECOVERING PORTFOLIO DEFAULT INTENSITIES IMPLIED BY CDO QUOTES

We propose a stable nonparametric algorithm for the calibration of “top‐down” pricing models for portfolio credit derivatives: given a set of observations of market spreads for collateralized debt obligation (CDO) tranches, we construct a risk‐neutral default intensity process for the portfolio underlying the CDO which matches these observations, by looking for the risk‐neutral loss process “closest” to a prior loss process, verifying the calibration constraints. We formalize the problem in terms of minimization of relative entropy with respect to the prior under calibration constraints and use convex duality methods to solve the problem: the dual problem is shown to be an intensity control problem, characterized in terms of a Hamilton–Jacobi system of differential equations, for which we present an analytical solution. Given a set of observed CDO tranche spreads, our method allows to construct a default intensity process which leads to tranche spreads consistent with the observations. We illustrate our method on ITRAXX index data: our results reveal strong evidence for the dependence of loss transitions rates on the previous number of defaults, and offer quantitative evidence for contagion effects in the (risk‐neutral) loss process.     

安徽省农村信用社贷款利率定价机制模式探索

建立健全农村信用社利率定价机制是稳步推进利率市场化改革的一项重要内容。但是,现行农村信用社利率管理模式难以适应利率市场化风险控制的要求,探索具有区域性特色的农村信用社利率定价机制模式,强化利率风险管理,对农村信用社的可持续发展具有重要意义。     

齐齐哈尔市社会信用体系建设的探讨

齐齐哈尔市在信用体系建设过程中现存在的问题:信用信息的泄漏及滥用严重;信用市场发育不完善,法律、法规不健全,缺少健全配套的信用体系。应强化政府主导作用,弱化垄断企业的强权行为,培育和发展市场经济中独立的信用评价体系,提高政府自身的信用形象,遏止信用缺失现象的发生,其有利于建设高效政府、高效的社会。     

MODEL‐INDEPENDENT NO‐ARBITRAGE CONDITIONS ON AMERICAN PUT OPTIONS

We consider the pricing of American put options in a model‐independent setting: that is, we do not assume that asset prices behave according to a given model, but aim to draw conclusions that hold in any model. We incorporate market information by supposing that the prices of European options are known. In this setting, we are able to provide conditions on the American put prices which are necessary for the absence of arbitrage. Moreover, if we further assume that there are finitely many European and American options traded, then we are able to show that these conditions are also sufficient. To show sufficiency, we construct a model under which both American and European options are correctly priced at all strikes simultaneously. In particular, we need to carefully consider the optimal stopping strategy in the construction of our process.     

A direct solution method for pricing options in regime‐switching models

Pricing financial or real options with arbitrary payoffs in regime‐switching models is an important problem in finance. Mathematically, it is to solve, under certain standard assumptions, a general form of optimal stopping problems in regime‐switching models. In this article, we reduce an optimal stopping problem with an arbitrary value function in a two‐regime environment to a pair of optimal stopping problems without regime switching. We then propose a method for finding optimal stopping rules using the techniques available for nonswitching problems. In contrast to other methods, our systematic solution procedure is more direct as we first obtain the explicit form of the value functions. In the end, we discuss an option pricing problem, which may not be dealt with by the conventional methods, demonstrating the simplicity of our approach.     

基于Credit Metrics模型的CDS定价研究

信用违约互换（Credit Default Swaps,CDS）作为当今国际上最流行的的信用衍生工具,被广泛应用于商业银行的信用风险管理中。Credit Metrics模型被广泛运用于度量信用风险的大小,在应用Credit Metrics模型计算商业银行贷款的VaR基础上探讨CDS的定价问题。以单笔贷款为例来说明该模型探讨CDS定价实际运用过程,对我国商业银行信用风险管理的提高有一定指导作用。     

Are credit spreads too low or too high? A hybrid barrier option approach for financial distress

Based on the works of Brockman, P. and Turtle, H. J. (2003) and Giesecke, K. (2004), we propose in this study a hybrid barrier option model to explain observed credit spreads. It is free of problems with the structural model, which underprescribed credit spreads for investment grade corporate bonds and overprescribed the high‐yield issues. Unlike the standard barrier option approach, our hybrid model does not imply, for high‐yield issues with firms under financial stress, a reduction of credit spreads while firm value actually falls. Our empirical analysis supports that when credit spreads are quoted abnormally higher or rising faster than expected, unexpected changes tend to persist. Otherwise a significant and prompt reversion to long‐term equilibrium takes place. This asymmetric pricing phenomenon is validated with a method introduced by Enders, W. and Granger, C. W. J. (1998) and Enders, W. and Siklos, P. L. (2001). The pricing asymmetry could not have been produced by a structural model employing only standard option. But it is consistent with a hybrid barrier option model. Our model characterizes the valuation of debt under financial stress and the asymmetric price pattern better than both the classical structural and the standard barrier option approaches. It can be extended to the study of individual CDS for its better liquidity than individual corporate bonds. This study provides helpful implications especially for the medium and high‐yield issues in pricing as well as portfolio diversification. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 29:1161–1189, 2009     

关于美国企业信用管理机制的思考

在市场经济条件下,信用是企业的无形资本。信用资本是现代企业的形象之基与发展之魂。现代企业不仅要积累信用资本,而且必须设立一套健全有效的维护机制。美国企业信用管理机制为完善我国企业信用管理机制建设提供了有益的启示