银行个体的信用评级及银行债务评级（上）

国际信用评级制度已有一百多年的历史，评级是关于评级对象未来违约概率的估价，随着市场经济的发展和经济运行不确定性的增强，信用评级在社会经济金融活动中发挥着越来越重要的作用。从经济学角度讲， 信用评级的作用主要表现为：一是解决投资与筹资（债务人）之间的信息不对称，减弱投资风险；二是向投资提供筹资（债务人）或某一机构的违约概率，评价其履行金融义务的能力；三是拓宽债务发行（筹资）的融资渠道，帮助其降低筹资费用。由于信用评级机构的评级活动和行为模式不受股东的影响、评估对象的压力和政府的干预，具有较高的独立性、而且依靠专业技术和内部管理来保证其资信评估的客观性，所以信用评级尤其是权威评级机构的评级结构具有较高的可信度，从而，信用评级的服务范围和服务领域不断扩展。     

The Effect of Bond Rating Changes and New Ratings on UK Stock Returns

This is the first study to use daily data from a major capital market outside of the US to examine the role of corporate bond and commercial paper rating changes on common stock returns. Using data published by Standard and Poors' credit rating agency between 1984 and 1992, we examine the impact of new credit ratings, credit rating changes and Credit Watch announcements on UK common stock returns. We find significant negative excess returns around the date of a downgrade and positive returns close to the date of a positive CreditWatch announcement. Hence, the financial markets would appear to place some importance on rating agency pronouncements in the UK. New ratings, whether short or long-term, have no significant impact on returns. We also attempt to quantify the impact of a new credit rating upon firm cost of capital through measures of conditional volatility and systematic risk. However, we find only weak evidence to suggest that a stock's cost of capital is reduced after a long-term credit rating is awarded for the first time.     

Combining Bond Rating Forecasts Using Logit

Companies sometimes use statistical analysis to anticipate their bond ratings or a change in the rating. However, different statistical models can yield different ratings forecasts, and there is no clear rule for which model is preferable. We use several forecasting methods to predict bond ratings in the transportation and industrial sectors listed by Moody's bond rating service. A variant of the ordered‐logit regression‐combining method of Kamstra and Kennedy 1998 yields statistically significant, quantitatively meaningful improvements over its competitors, with very little computational cost.     

公司债特殊条款、债券评级与会计稳健性

本文基于债券持有人利益保护视角,以手工收集的2007-2016年沪深A股上市公司发行的公司债特殊条款为样本,研究公司债特殊条款对会计稳健性的影响,以及债券评级的调节作用,并基于公司治理机制和代理冲突角度,探究公司债特殊条款影响会计稳健性的作用机理。研究发现,公司债特殊条款数量越多(约束强度越大),发债主体会计稳健性水平越高;债券评级越低,公司债特殊条款对会计稳健性的正效应越大。进一步研究发现,在国有企业、公司治理水平低以及代理冲突严重的情况下,公司债特殊条款数量对债务主体会计稳健性具有正效应。本研究为不同缔约主体以及政府监管部门防范债券违约风险、治理违约事件、提高债券契约执行效率提供理论参考与经验借鉴。     

我国信用评级在债券市场中的供给及应用

金融监管对信用评级的需求
　　信用评级的需求有赖于整体经济的信用活动,我国信用评级的发展应当主要依赖银行信贷市场。这与我国长期依赖银行作为主要融资渠道,资本市场特别是债券市场发展滞后不无关系。但随着金融脱媒进程加速、债券市场快速发展以及资产证券化等金融创新产品的出现,银行作为信用中介和信息中介的功能相对弱化,直接融资逐渐成为资金市场上主要融资方式之一,银行的部分信息中介功能被信用评级替代。     

Risk and Return Around Bond Rating Changes: New Evidence From the Spanish Stock Market

Abstract:  This study analyzes the effect of corporate bond rating changes on stock prices in the Spanish stock market. We explore their effects on excess of returns and systematic risk. Rating changes by Moody's, Standard and Poor's and FitchIBCA are analyzed. On an efficient market, these changes will only have some effect if they contain some new information or if they are associated to a redistribution of wealth between shareholders and bondholders. We use an extension of the event study dummy approach. Our results support the redistribution of wealth hypothesis in the abnormal returns behavior. We also find that changes in both directions cause a rebalancing effect in the total risk of the firm, with significant reductions on their systematic component.     

Information Transfer Effects of Bond Rating Downgrades

This paper investigates information transfer effects of bond rating downgrades measured by equity abnormal returns for industry portfolios. Industry rivals can be subject to two opposing effects, the contagion effect and the competition effect. We find that the net effect is strongly dependent on the original bond rating of the downgraded firm. For investment‐grade (speculative‐grade) firms, industry abnormal equity returns are negative (positive), which implies a predominant contagion (competition) effect. The analysis reveals a rich pattern of positive and negative correlations across negative credit events, which can be used to improve our understanding of portfolio credit risk models.     

The Effect of Bond Rating Agency Announcements on Bond and Stock Prices

This paper examines daily excess bond returns associated with announcements of additions to Standard and Poor's Credit Watch List, and to rating changes by Moody's and Standard and Poor's. Reliably nonzero average excess bond returns are observed for additions to Standard and Poor's Credit Watch List when an expectations model is used to classify additions as either expected or unexpected. Bond price effects are also observed for actual downgrade and upgrade announcements by rating agencies. Excluding announcements with concurrent disclosures weakens the results for downgrades, but not upgrades. The stock price effects of rating agency announcements are also examined and contrasted with the bond price effects.     

What Is in a Municipal Bond Rating?

Studies on the determinants of municipal bond ratings contain two conspicuous patterns: the use of financial accounting variables and the application of discriminant analysis to them. Over 70 different financial accounting variables have been specified, leading to different findings across the studies. In addition, discriminant analysis has been applied in these studies without correcting for violations of its underlying assumptions. Akaike's information criterion and Lachenbruch's U method are used to show how a probit model specified with economic base diversification, economic expansion, and fiscal management variables may be an improvement over the application of discriminant analysis to financial accounting variables in the determination of a triple A bond rating.     

Bond vs stock market's Q: Testing for stability across frequencies and over time

In this paper we revisit the evidence recently provided by Philippon (2009) about the relationship among bond market's Q, stock market's Q and aggregate investments for the US. Specifically, we analyze the stability of the relationship between aggregate investment and the two measures of Q across frequencies and over time. We find that the relationship between aggregate investment and stock market's Q, in contrast to that with bond market's Q, is both frequency-dependent and time-varying. Both the successfulness of bond market's Q and the poor performance of the usual Tobin's Q can be explained by taking into account stability across frequencies of the first and instability over time of the latter.     

会计信息在公司债信用等级迁移中的预测作用研究

本文利用中国银行间债券市场和交易所市场中公司债的数据,基于因子分析法构建Logistic模型探讨会计信息在公司债信用等级动态迁移中的预测作用。研究表明本文所构建的模型无论是对建模用的训练样本还是模型之外的测试样本均有较高的预测精度,发债主体的财务状况与经营成果是公司债信用等级迁移的重要驱动力,特别是发债主体的盈利能力、营运能力和现金流量显著影响信用等级的变化。本文的实证结果证明会计信息在我国公司债市场中具有价值相关性。     

多重信用评级与债券融资成本——来自中国债券市场的经验证据

本文揭示了多重信用评级的信息生产机制和信用认证机制,排除了“信用评级购买”假说对于多重评级动机的解释,研究发现:多重信用评级有利于降低债券融资成本;相对于不一致的多重信用评级,一致的多重信用评级更有利于降低债券融资成本。在多重信用评级中,相对于评级机构均为“发行人付费”模式,兼有“投资者付费”模式的信用评级更有利于降低债券融资成本。此外,当多重信用评级的评级意见不一致时,平均评级的信息含量最高,即综合不同信用评级所包含的多种信息比任何单一信用评级更加具有信息含量。本研究为我国债券市场双评级制度提供了理论和经验证据的支持,有助于完善多元化信用评级制度和债券市场监管制度,并提示发债企业可以通过多重信用评级向市场传递更多和更具效度的评级信息,以弥补单一信用评级的信息不足和评级结果失准,减少投资者决策的不确定性,从而降低债券融资成本。     

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。     

Assessing Credit Rating Agencies by Bond Issuers and Institutional Investors

We examine how a sample of publicly traded corporate bond issuers and institutional investors assess the four major nationally recognized rating agencies and their role in capital markets. The results show that issuers and investors differ dramatically in their assessments about rating agencies. Specifically, the majority of institutional investors require only one rating when they buy rated corporate bonds, but most issuers obtain two or more ratings. Issuers and investors also differ in their assessments about whether ratings accurately reflect creditworthiness and timeliness. The results suggest that differences reflect the different roles that rating agencies provide in the market place.     

Are All Rivals Affected Equally by Bond Rating Downgrades?

We use revisions in analysts' earnings forecasts to examine how the bad news associated with a bond rating downgrade gets transferred from the downgraded company to its rivals. In general, we find that stock analysts revise their earnings expectations downward for rivals of companies with downgraded debt. However, the significance of the revision is limited to rivals of downgraded companies with non-investment grade debt only. For the rivals of companies with investment grade debt, we find no significant forecast revisions. We hypothesize that this differential impact is due to differing levels of market visibility. This is consistent with our finding that downgraded companies with non-investment grade debt are followed by significantly fewer stock analysts. Apparently not all rivals are affected equally by bond rating downgrades.