Bankruptcy probability changes and the differential informativeness of bond upgrades and downgrades

Prior studies have found that stock returns around announcements of bond upgrades are insignificant, but that stock prices respond negatively to announcements of bond downgrades. This asymmetric stock market reaction suggests either that bond downgrades are timelier than upgrades, or that voluntary disclosures by managers preempt upgrades but not downgrades. This study investigates these conjectures by examining changes in firms’ probabilities of bankruptcy (assessed using bankruptcy prediction models) and voluntary disclosure activity around rating change announcements. The results indicate that the assessed probability of bankruptcy decreases before bond upgrades, but not after. By contrast, the assessed probability of bankruptcy increases both before and after bond downgrades. We also find that controlling for potential wealth-transfer related rating actions, which can impact stock returns differently, does not alter our results. Tests of press releases and earnings forecasts issued by firms suggest that the differential informativeness of upgrades and downgrades is not caused by differences in pre-rating change voluntary disclosures by upgraded and downgraded firms. The results support the hypothesis that downgrades are timelier than upgrades.     

信用评级中的违约率、违约概率研究

信用评级是对个人、经济体与金融工具履行各种经济承诺的能力及可信任程度的综合评价，本文通过对KMV评级模型的研究，指出在信用评级中的关键指标——“违约率和违约概率”在评级中的重要意义。     

Selecting credit rating models: a cross-validation-based comparison of discriminatory power

In commercial banking, various statistical models for corporate credit rating have been theoretically promoted and applied to bank-specific credit portfolios. In this paper, we empirically compare and test the performance of a wide range of parametric and nonparametric credit rating model approaches in a statistically coherent way, based on a ‘real-world’ data set. We repetitively (k times) split a large sample of industrial firms’ default data into disjoint training and validation subsamples. For all model types, we estimate k out-of-sample discriminatory power measures, allowing us to compare the models coherently. We observe that more complex and nonparametric approaches, such as random forest, neural networks, and generalized additive models, perform best in-sample. However, comparing k out-of-sample cross-validation results, these models overfit and lose some of their predictive power. Rather than improving discriminatory power, we perceive their major contribution to be their usefulness as diagnostic tools for the selection of rating factors and the development of simpler, parametric models.

Determinants of Sovereign Eurobonds Yield Spread

We examine the determinants of sovereign Eurobond spread at issuance covering 1991–2000. The results of the regression models showed that yield spread increases with maturity, issue size and gross fees and decreases with credit rating and the number of managers. Higher‐grade issuers also pay a relatively higher spread to borrow long‐term funds and for smaller issues. The findings are consistent with the notion of a term structure 'liquidity premium.' Low‐grade issuers pay a higher spread than better‐rated countries. However, low‐grade countries pay high spread for larger funds. Credit rating is found to provide additional information in explaining the spread on sovereign Eurobonds beyond that provided by macroeconomic variables.     

Exploring the components of credit risk in credit default swaps

In this paper, we test the influence of various fundamental variables on the pricing of credit default swaps. The theoretical determinants that are important for pricing credit default swaps include the risk-free rate, industry sector, credit rating, and liquidity factors. We suggest a linear regression model containing these different variables, especially focusing on liquidity factors. Unlike bond spreads which have been shown to be inversely related to liquidity (i.e., the greater the liquidity, the lower the spread), there is no a priori reason that the credit default swap spread should exhibit the same relationship. This is due to the economic characteristics of a credit default swap compared to a bond. Our empirical result shows that all the fundamental variables investigated have a significant effect on the credit default swap spread. Moreover, our findings suggest that credit default swaps that trade with greater liquidity have a wider credit default swap spread.     

Contagion effect on bond portfolio risk measures in a hybrid credit risk model

This paper illustrates how modelling the contagion effect among assets of a given bond portfolio changes the risk perception associated to it. This empirical work is developed in a hybrid credit risk framework that incorporates recovery rate risk. Dependence structures among firms and between external shocks affecting firms together are considered. The presence of correlations among firm leverage ratios and the interrelation between default probabilities and recovery rates produces clusters of defaults with low recovery rates. This has a major impact on standard risk measures such as Value-at-Risk and conditional tail expectation. Consequently, an appropriate measurement of the contagion has a tremendous effect on the capital requirement of many financial institutions.     

Does reputation matter? Evidence on spatial competition in China's bond market

This study investigates the effect of market competition on the reputational concerns of credit rating agencies (CRAs) in the Chinese bond market. We find credit ratings increase when the market share distance between an incumbent CRA and its closest peer competitor decreases. This spatial competition effect only exists at the provincial level. We also find the market competition deteriorates the ability of ratings to predict future bond defaults, while the correlation between credit ratings and market-implied credit spreads is unaffected. Our findings suggest that because of the market inefficiency in emerging economies, CRAs privilege current profits over reputational concerns.     

信任被定价了吗？ ——来自债券市场的证据

仅依赖法律等正式制度无法确保金融或经济的长期发展,信任等非正式制度在其中的作用不可或缺。鉴于此,本文研究信任这一非正式制度在债券市场中的价值。研究发现,信任不仅有助于提高债券信用评级,还有助于降低债券信用利差。同时,利用最高法“失信被执行人”数据还发现,失信及失信程度的增加会降低债券信用评级,提高债券信用利差。此外,本文还利用路径分析法发现,信任不仅会直接影响债券评级和定价,还会通过提升公司财务报告质量间接地发挥作用,即不仅投资者主观上更愿相信高信任度地区的企业,客观上这些企业也的确更为可信。进一步地,信任对债券评级和定价的积极作用在国有企业、金融业更发达地区的企业以及发债次数更多的企业中更为显著,即投资者与发行人之间的重复博弈机会越多,信任的价值也越大。本文研究结论提醒政府在推动企业融资成本下降时,应着重加强对信任这种地区乃至国家公共品的培育和建设。     

我国信用风险缓释市场发展与创新

随着我国融资市场快速发展,信用风险管理面临严峻挑战,信用风险缓释市场亟待发展创新.然而,受金融危机影响,我国金融从业人员在观念、认识和态度上对信用风险缓释工具(CRM)存在诸多不明.本文通过解析CRM市场结构、CDS定价机制,以及中国CRM市场发展对策,帮助金融从业人员正确认识CRM市场功能,提升CRM市场参与能力,为...     

劳动投资效率、企业性质与资产收益率

基于中国信用债券市场的近期违约事件,本文研究发现:涉事评级机构不仅没有因为涉及债券违约事件而收紧信用评级标准,反而更加高估企业的信用评级水平,并且涉及的债券违约事件越多,高估信用评级的程度越大。但投资者通过“用脚投票”方式惩罚了涉事评级机构,导致其市场份额相对于非涉事评级机构出现显著下降或者增长较低的态势,同时涉事评级机构的信用评级意见对于降低企业融资成本的作用显著降低。