Market structure and rating strategies in credit rating markets – A dynamic model with matching of heterogeneous bond issuers and rating agencies

This paper investigates the impact of rating agencies in a market with asymmetric information. In particular, the role of credit rating agencies as an intermediary between investors and bond issuers is discussed. We model this setting in a dynamic framework in which both rating agencies and bond issuers are of heterogeneous quality. Rating agencies can apply costly research technology to reveal the fundamental nature of bond issuers and engage in rating smoothing. We show that rating smoothing can compensate for low research quality, even though it is accompanied by a quality deterioration in the rating market and market clustering. Moreover, low-quality bond issuers have a general tendency to match with low-quality rating agencies. If investors place a strong emphasis on the reputation of rating agencies, rating markets also tend to be strongly clustered.     

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。     

债券评级机构变更——基于评级选购与评级迎合视角

本文以2008年至2017年的公司债券为样本,研究了发行人变更评级机构的影响,以此来解释评级市场上发行人频繁变更评级机构的现象。本文发现发行人变更评级机构后,其信用等级得到显著提升。发行人变更评级机构的行为对信用等级的影响在以下两种情形中更显著:一是当发行人所处行业或评级机构所在的评级市场竞争激烈时;二是当发行人主体评级位于AA信用等级的临界点时。进一步研究发现,考虑到评级机构变更与信用等级之间的交互影响,变更评级机构的发行人整体上可实现发债成本的降低。但该类发行人未来的违约风险增加、经营业绩下降。最后,本文发现债券发行规模较大以及非国有发行人更倾向于变更评级机构来提高信用等级。本文通过分析发行人更换信用评级机构的动机和后果,为监管部门构建以评级质量为导向的良性竞争环境提供借鉴参考。     

私有信息、评级偏差和中国评级机构的市场声誉

考虑到评级机构拥有市场声誉的本质在于其可以通过扭曲评级从而对市场产生影响,本文分两步研究中国发行人付费评级机构的市场声誉:第一步,将信用评级对各种基本面因素进行回归,并以实际评级与回归预测值的差值作为评级偏差的量度。与既有文献相比,本文的重要改进是在基本面因素中引入了发债企业与各评级机构(分支机构)最短距离的均值和方差,这能较好地控制因发债企业私有信息可能造成的选择偏误。第二步,考察评级偏差和机构特征如何影响企业的发债成本。研究表明,中国评级机构作为一个整体具有显著的市场声誉,但各评级机构之间存在很大的差异性。最后,考虑到评级机构与发债企业在选址上可能会有集聚效应,我们基于高铁开通事件进行双重差分检验,研究表明本文结论是稳健的。     

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.     

“投资人付费”vs.“发行人付费”:谁的信用评级质量更高？

本文选择2011-2015年被中债资信覆盖的发债A股上市公司作为主要研究对象,比较了“投资人付费”与“发行人付费”模式下的评级质量高低。研究发现:(1)与“发行人付费”评级相比,采用“投资人付费”模式的中债资信所作评级显著更低。(2)与“发行人付费”评级相比,当采用“投资人付费”模式的中债资信所作评级越低时,发行人未来盈利能力越差、预期违约风险越高,投资者要求的风险补偿也越高,这表明“投资人付费”模式下的信用评级质量更高。(3)“发行人付费”模式的评级结果可以在一定程度上反映公司的内部私有信息,但由于同时存在独立性缺失问题,“发行人付费”模式的信用评级质量仍然不如“投资人付费”模式的信用评级质量,这说明独立性对于评级机构尤其重要。     

信用评级收费模式:机制与选择

本文对资信评级机构的收费模式进行了经济学分析,认为由于声誉机制的作用和信息交易中搭便车因素的影响,中小型评级机构只能够对投资者收费,大型评级机构才可能采取向证券发行人收费的模式。中国的资信评级机构从历史信誉和公司规模都是中小型机构,采取对证券发行人免费评级、向投资者收费的模式是当前我国评级机构的必然选择。     

Seniority Differentials in High Yield Bonds: Evolution,Valuation, and Ratings

Almost 20 years ago, one of the coauthors of this article published a study that reported finding systematically wider yield spreads on senior corporate bonds than on subordinated bonds with the same credit rating, but issued by different companies. The study also showed that this difference in spreads did not represent a market “anomaly” or failure to price risk correctly, but instead reflected differences in the actual, and hence the expected, loss rates of the securities. And such differences were in turn shown to stem from the practice of the rating agencies—which was abandoned about ten years ago—of rating a given issuer's subordinated debt two “notches” below that of its senior debt. Partly in response to this finding, all of the major agencies modified their use of this “two‐notch” convention by initiating in‐depth fundamental analysis of subordinated issuers on a case‐by‐case basis. In the meantime, the near disappearance of subordinated debt in the high yield market since the global financial crisis and its partial replacement by secured debt has furnished the authors of this article with a seemingly related “anomaly” to explore—namely, the tendency of secured bonds to have higher yields than samerated senior unsecured bonds. As in the earlier study of the senior‐subordinated puzzle, the authors' analysis confirms that the market has been properly pricing the relative risks of the different securities by showing that the actual loss rates of the secured issues have been systematically higher than those of like‐rated senior unsecured issues. The clear suggestion of these findings, as in the case of the earlier study, is that those investors who have chosen to incur the costs of analyzing expected loss rates instead of relying solely on the ratings have been rewarded for their efforts. And if the past is a guide to the future, this article may also succeed in spurring the rating agencies to make further refinements to their methods.     

Insider employee stock option trading and stock prices

The question of which factors determine corporate bonds pricing is investigated by analysing the spreads of eurobonds issued by major G-10 companies during the 1991–2001 period. Three main results emerge from the analysis. First, bond ratings appear as the most important determinant of yield spreads, with investors’ reliance on rating agencies judgments increasing over time. Second, the primary market efficiency and the expected secondary market liquidity are not relevant explanatory factors of spreads cross-sectional variability. Finally, rating agencies adopt a different, ‘through the cycle’, evaluation criteria of default risk with respect to the forward looking one adopted by bond investors.     

中介机构信息有效性、投资策略与资源合理配置——以经济观察研究院“信任度指数”为例

本文研究中国证券市场民间分析机构信息的有效性、价值含量及其在证券市场资源配置中的作用。以经济观察研究院发布的“上市公司信任度指数”为研究对象,我们发现:信任度指数准确反映了公司的财务信息质量;该信息在投资决策中是有效的,利用其构建的对冲策略可以获得月平均2.7%的超额回报(年均32.4%)。我们的结果表明,如果投资者能够充分利用中介结构披露的信息,就可以从一定程度上缓解我国当前资本市场中的信息不对称问题,促进证券市场资源合理配置。     

Investors’ heterogeneous beliefs and the impact of sovereign credit ratings in foreign exchange and equity markets

We propose a model in which sovereign credit news from multiple rating agencies interacts with market heterogeneity. The model illustrates that the first messenger discloses new information while additional messengers play an important role of coordinating heterogeneous beliefs. Empirical investigations based on sovereign credit ratings, foreign exchange and equity markets confirm that rating news coordinates investors’ beliefs. Sovereign credit rating news from both types of messenger induces a significant impact on exchange rates and stock indices. Volatility measures increase in response to news from the first messenger while ex-post volatility reduces following news from an additional messenger.     

债券市场的评级信息能改善股票市场信息环境吗?——来自分析师预测的证据

本文研究发现,信用评级增加了分析师预测的公共信息,同时没有减少分析师预测的私有信息,即信用评级信息能够改善股票市场信息环境。具体地,本文利用2006-2016年上市公司数据实证发现,信用评级能显著提高分析师预测精度、降低分析师预测分歧度与乐观偏差,且这种效应在信息不对称程度高、低能力分析师跟踪的企业以及外资参股的评级机构中更加显著,这说明信用评级向分析师提供了新的信息。进一步地,信用评级只增加了分析师预测的公共信息,对私有信息没有显著影响,同时也不影响分析师的调研行为,上述结论表明信用评级信息披露并不影响分析师拥有私有信息的优势,且信用评级机构与分析师之间存在互补而非替代关系。因此,金融监管应该加强对评级机构尽职调研的要求,充分发挥信用评级机构的信息中介功能。     

Rating agencies and the role of rating publication rights

While credit rating agencies disclose all public ratings as a matter of policy, a firm can choose whether to make a so called private rating public or to keep it confidential. This paper analyzes the economic role of such rating publication rights. In particular, the paper tries to answer the following two questions: (1) If firms have scope to disclose agency ratings at their own discretion, can they use this discretion strategically and conceal low-quality ratings?, and (2), if this is the case, what are the economic implications for rated firms, unrated firms and the rating agency, resulting from strategically motivated selective rating disclosures? Using a theoretical model, it is shown that an equilibrium with partial nondisclosure of low-quality ratings can emerge whenever investors cannot be sure whether rating nondisclosure is due to the firm being not rated, or due to the rating’s adverse content. Moreover, since from an investors’ perspective, strategically acting rated firms and unrated firms are pooled, unrated firms’ debt is always under-valued (compared to a situation in which investors know that the firm is not rated), and the debt of firms concealing their rating is always over-valued.     

Do credit rating agencies add to the dynamics of emerging market crises?

This study investigates the role of credit rating agencies in international financial markets. With an index of speculative market pressure it is analyzed whether sovereign ratings changes have an impact on the financial stability in emerging market economies. The event study analysis indicates that sovereign rating changes have substantial influence on the size and volatility of emerging markets lending. The empirical results are significantly stronger in the case of government's downgrades and negative imminent rating actions than in the case of agencies’ positive rating adjustments. Sovereign rating changes anticipated by market participants have a smaller impact on financial markets in emerging economies.     

INFORMATION OPACITY AND FITCH BOND RATINGS

We examine the marginal impact of Fitch ratings on the at‐issuance yields of industrial and utility bonds rated by Moody's and Standard & Poor's. We find that Fitch ratings reduce the yield premiums on information‐opaque bonds by about 30%, or 15 basis points. The finding is robust even when a Fitch rating exactly equals the two major ratings or their average. The findings suggest that Fitch ratings are not redundant but bring additional information to investors. Increased competition in the rating industry enhances the information efficiency of the bond market, and the existence of smaller rating agencies is economically justified.     

The impact of sovereign credit ratings on Eurobond yields: Evidence from Africa

The importance of sovereign credit ratings and Eurobonds issued by governments have come to the fore in Africa in the last decade. We examine whether changes in sovereign credit ratings impact Eurobond yields in 8 countries over the period of 2014–2019. Our approach reviews rating changes impact on Eurobond yields utilising the event study methodology. Our findings reflect that, on average, close to a third of rating actions directly impact bond yields in African countries. The statistically significant events include the downgrades of South Africa and Namibia to non-investment grade in 2017 reflecting critical transitions and bond investors’ reactions. Overall, the low percentage of a third, relative to previous international studies, suggests that largely rating changes are anticipated, do not have much new information and perhaps the perceived power of credit rating agencies may be overstated. In our view, the results reflect that pre-announcements of rating review dates since 2014 makes rating actions predictable and less impactful to bond yields. In addition, they reflect that bond investors adjust in real time as new information come in, resulting in less reliance on the opinions of CRAs and using their own assessments.     

经济政策不确定性、声誉机制与信用评级

本文以2007-2019年我国企业债券为样本,采用有序Probit回归模型探讨经济政策不确定性对信用评级的影响,研究结果表明:(1)经济政策不确定性的增加会促使评级机构显著降低信用评级,这种影响因产权性质存在显著差异,而且在债券市场刚性兑付被打破后更为显著;(2)声誉机制对上述影响产生积极的调节效应,声誉受损或声誉水平较高的评级机构会更加谨慎地评估经济政策不确定性的影响效应。基于此,政府应合理管控政策的出台和调整以增强社会预期,监管机构要不断强化对评级机构的监管,促使评级机构提高信用评级的质量。     

Ratings quality over the business cycle

Credit rating agencies (CRAs) have long held that reputational concerns discipline their behavior. The value of reputation, however, depends on economic fundamentals that vary over the business cycle. In a model of ratings incorporating endogenous reputation and a market environment that varies, we find that ratings quality is countercyclical. Specifically, a CRA is more likely to issue less-accurate ratings when fee-income is high, competition in the labor market for analysts is tough, and securities' default probabilities are low. Persistence in economic conditions can diminish our results, while mean reversion exacerbates them. The presence of naive investors reduces overall quality, but quality remains countercyclical. Finally, we demonstrate that competition among CRAs yields similar results.     

Good disclosure doesn't cure bad accounting—Or does it?: Evaluating the case for SFAS 158

This paper investigates whether the newly required recognition of the funded status of defined benefit (DB) plans under SFAS 158 is incrementally value relevant in its adoption year (2006) relative to the corresponding amounts which were previously disclosed from both equity investor and credit rating perspectives. In equity valuation models, we use a sample of 878 firms (1756 firm years) offering DB plans in 2005 (disclosure year) and 2006 (recognition year), and find no incrementally significant association with market prices of newly recognized amounts under SFAS 158 over the same information that was disclosed pre-SFAS 158. Our credit rating tests, using a sample of 428 DB firms (856 firm years) for 2005 and 2006 also show no differential impact of recognition over disclosure. Overall, we find that equity investors price the SFAS 158-imposed pension differential while credit rating agencies do not, regardless of whether such information is recognized or disclosed in the financial statements. Our results are consistent with efficiency in both equity and credit markets with respect to pension information and suggest that SFAS 158 has not changed the way market participants in aggregate use pension-related financial statement information.