Moody's and S&P Ratings: Are They Equivalent? Conservative Ratings and Split Rated Bond Yields

We examine the relative impact of Moody's and S&P ratings on bond yields and find that at issuance, yields on split rated bonds with superior Moody's ratings are about 8 basis points lower than yields on split rated bonds with superior S&P ratings. This suggests that investors differentiate between the two ratings and assign more weight to the ratings from Moody’s, the more conservative rating agency. Moody's becomes more conservative after 1998 and the impact of a superior Moody's rating becomes stronger. Furthermore, the differential impact of the two ratings is more pronounced for the more opaque Rule 144A issues.     

Reaching for Yield in the Bond Market

This paper studies reaching for yield—investors’ propensity to buy riskier assets to achieve higher yields—in the corporate bond market. We show that insurance companies reach for yield in choosing their investments. Consistent with lower rated bonds bearing higher capital requirements, insurance firms prefer to hold higher rated bonds. However, conditional on credit ratings, insurance portfolios are systematically biased toward higher yield, higher CDS bonds. This behavior is related to the business cycle being most pronounced during economic expansions. It is also characteristic of firms with poor corporate governance and for which the regulatory capital requirement is more binding.     

Do Bond Covenants Affect Borrowing Costs?

High yield bond investors spend a great deal of time studying covenants. They even hire specialized consultants to help them interpret the dense language of indentures. But for all that, does a company's decision to offer strong rather than weak covenants—or to offer covenants at all—have a measurable impact on its borrowing costs? There is surprisingly little evidence that variation in credit risk premiums reflects the presence or absence of covenants. Taking advantage of a newly available kind of data—Moody's Investors Service's Covenant Quality (CQ) ratings, which were initiated in 2011—the authors studied each newly issued U.S. high yield bond beginning in 2011 using Moody's CQ ratings, where a rating of “1” represents the strongest covenant rating and “5” the weakest. The authors hypothesize that if investors are willing to pay for covenant protection, bonds with weak CQ scores should have spreads that are higher, on average, than the medians of the bonds in their rating group. What they found, however, was that even bonds rated CQ5, indicating negligible protection, had spreads that were only 9.54 basis points higher than the median of companies with the same credit rating. The authors also found, contrary to their initial supposition, that higher yields were associated with stronger covenants, suggesting that investors demand more protection on issues they view as having greater credit risk than other equivalently rated issues.     

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.     

Rating Agency Reputation,the Global Financial Crisis,and the Cost of Debt

Why do foreign firms obtain credit ratings by global rating agencies rather than from their home country's rating agencies even though global raters typically assign lower credit ratings when these foreign firms issue bonds in their home currencies? We find that bonds rated by a global agency decreased yields 11‐14 basis points (bps) when compared to those rated by Japanese rating agencies but, during the 2007‐2009 financial crisis, the yields on these Japanese bonds increased 12‐17 bps, thus fully negating the advantage of obtaining a bond rating from a global rater. This suggests that the reputation of global rating agencies declined during the 2007‐2009 crisis period.     

Estimating the Equity Risk Premium and Expected Equity Rates of Return: The Case of Canada

It is common to use the average excess return of equities over bonds estimated over long time periods as an expected equity risk premium on the grounds that going back far enough covers most possible economic scenarios. But although this data is useful in guiding the exercise of judgment, it cannot substitute for judgment. Adding more years of data to the near century of Canadian stock and bond returns that inform today's estimate of the equity risk premium will not produce a “random walk” for a simple reason: the historic bond series is the result of a specific historic monetary policy. This is particularly true of and important for the case of Canada, where today's very low current bond yields reflect the emergence of the Canadian dollar as a reserve currency as well as the impact of unconventional monetary policy elsewhere. After analyzing the historic record of the Canadian equity risk premium and noting the need for adjustments when this premium is applied to the current anomalously low Canadian long‐term bond yields, the author reaches the following conclusions:

• The historic Canadian equity risk premium is approximately 5.0% (based on arithmetic returns), which is slightly lower than the roughly 6.0% value for the U.S.
• The historic equity risk premium has not been constant because of obvious changes in the Canadian bond market. To some extent, the huge cycle in which bond yields began their increase from the 4.0% level starting in 1957, when markets were liberalized, and then fell back to the 4.0% level in 2007‐2008 completed an adjustment to changes in fiscal versus monetary policy. However, in 2016, average long Canada bond yields dropped to an anomalously low 1.8%, which is below the long‐term inflation target of the Bank of Canada, and have barely recovered since. It is difficult to view this as an equilibrium rate determined by private investors.
• Of the drop in bond yields, about 0.50% is unique to Government of Canada bonds as they became attractive to sovereign investors as a rare AAA‐rated issuer.
• Using an indicator variable for the post‐2010 years, a simple regression analysis indicates that current long Canada bond yields should be about 2.75% higher but for the recent changes. And for 2018, this means that the 2.35% average long Canada bond yield should have been about 5.0%. Apart from the impact of higher government deficits, this is consistent with average yields before the 2008 financial crisis.
• Adding an adjusted 5.0% long Canada bond yield to the historic equity risk premium in Canada of 4.50% gives 9.50% for the cost of the overall equity market or, given the Bank of Canada's target inflation rate of 2.0%, a real equity return of 7.5%, both slightly higher than the long‐run averages.

In sum, the conventional practice of adding a historic market risk premium to the current low Canada long bond yields would impart a sharp downward bias to current equity cost estimates; use of this method would not be appropriate until long Canada bond yields increase to at least the 4.0% level.     

Linking wealth and labour income with stock returns and government bond yields

In this paper, I assess the predictive ability of the ratio of asset wealth to labour income for both stock returns and government bond yields. Using data for 16 Organization for Economic Co-operation and Development (OECD) countries, I show that when the wealth-to-income ratio falls, investors demand a higher stock risk premium. A similar link can be found for government bond yields when agents behave in a non-Ricardian manner or see government bonds as complements for stocks. In contrast, when investors display a Ricardian behaviour or perceive stocks and government bonds as good substitutes, a fall in the wealth-to-income ratio is associated with a fall in future bond premium.     

Liquidity,default, taxes,and yields on municipal bonds

We examine the effects of liquidity, default and personal taxes on the relative yields of Treasuries and municipals using a generalized model with liquidity risk. The municipal yield model includes liquidity as a state factor. Using a unique transaction dataset, we estimate the liquidity risk of municipals and its effect on bond yields. Empirical evidence shows that municipal bond yields are strongly affected by all three factors. The effects of default and liquidity risk on municipal yields increase with maturity and credit risk. Liquidity premium accounts for about 9–13% of municipal yields for AAA bonds, 9–15% for AA/A bonds and 8–19% for BBB bonds. A substantial portion of the maturity spread between long- and short-maturity municipal bonds is attributed to the liquidity premium. Ignoring the liquidity risk effect thus results in a severe underestimation of municipal bond yields. Conditional on the effects of default and liquidity risk, we obtain implicit tax rates very close to the statutory tax rates of high-income individuals and institutional investors. Furthermore, these implicit income tax rates are quite stable across bonds of different maturities. Results show that including liquidity risk in the municipal bond pricing model helps explain the muni puzzle.     

Information uncertainty,information asymmetry and corporate bond yield spreads

This study examines the effects of information uncertainty and information asymmetry on corporate bond yield spreads using American data from 2001 to 2006. Empirical results of this study show that investors charge a significant risk premium for both information uncertainty and information asymmetry when controlling for variables well known in the literature. The results are robust even when controlling for credit ratings. Finally, information uncertainty and asymmetry help structural-form credit models explain the yield spreads of bonds with short maturities.     

On the consistency of ratings and bond market yields

We study the consistency of the credit-risk orderings implicit in ratings and bond market yields. By analyzing errors in term structure estimates for bonds with particular ratings, we show that for significant periods, a quarter of some categories of high credit quality bonds are rated in a manner that is inconsistent with their pricing. Adjusting for economic determinants of spreads (tax, liquidity and risk premiums) and allowing for the dynamic adjustment of ratings and spreads largely eliminates the inconsistencies, however.     

SPLIT RATINGS,BOND YIELDS,AND UNDERWRITER SPREADS

A split bond rating occurs when Moody's and Standard & Poor give different ratings to the same issue. We examine 1,277 public industrial bond issues, where 221 have split ratings, issued from 1980 through mid-1993. For split-rated industrial bonds, neither rating agency consistently gives higher ratings. Earlier studies find yields for split-rated bonds to be priced as either the higher or the lower of the ratings. We find the yields on split-rated bonds to be an average of the yields on the two ratings. Split ratings for industrial bonds appear to reflect random differences on the part of rating agencies. Our results differ from previous studies because we use a substantially larger sample and include high-yield bonds. As long as a bond has an investment-grade rating, the underwriter fees are found to be essentially the same for all rating categories. Below investment grade, the rating substantially affects the underwriter fee. Thus, split ratings for high-yield bonds have an important effect on the underwriter spread.     

Corporate bond yields and returns: a survey

Corporate bonds offer higher yields than government bonds with similar maturity. This higher reward comes at the cost of higher risk. The question then arises of how this risk is priced into corporate bonds. This literature review provides a classification and summary of papers studying corporate bond prices and the premium they offer to investors over the return on risk-free securities. The review ranges from theoretical models to empirical determinants of corporate bond prices. A specific section is dedicated to the liquidity impact as this component has received special attention.

     

Tranching and Rating

In this paper we analyse the source and magnitude of marketing gains from selling structured debt securities at yields that reflect only their credit ratings, or specifically at yields on equivalently rated corporate bonds. We distinguish between credit ratings that are based on probabilities of default and ratings that are based on expected default losses. We show that subdividing a bond issued against given collateral into subordinated tranches can yield significant profits under the hypothesised pricing system. Increasing the systematic risk or reducing the total risk of the bond collateral increases the profits further. The marketing gain is generally increasing in the number of tranches and decreasing in the rating of the lowest rated tranche.     

Split bond ratings and rating migration

This paper examines the relationships between split ratings and ratings migration. We find that bonds with split ratings are more likely to have future rating changes. A one-notch (more-than-one-notch) split rating increases the probability of rating change within one year of initial issuance by about 3% (6%). Furthermore, we find that about 30% of split rated bonds have their two ratings converge after four years of initial issuance. The rating convergence tapers off after three years, and the rating agency with a higher (lower) initial rating generally maintains a higher (lower) rating in subsequent years if the two ratings do not converge. We also show that rating transition estimation can be improved by taking into consideration split ratings. We find that one-year rating transition matrices are significantly different between non-letter-split rated bonds and letter-split rated bonds, and we show that the difference has an economically significant impact on the pricing of credit spread options and VaR-based risk management models. Overall, our results suggest that split ratings contain important information about subsequent rating changes.     

THE EFFECT OF MONETARY POLICY ON CREDIT SPREADS

We analyze the effect of monetary policy on yield spreads between corporate bonds with different credit ratings over the business cycle. We use futures contracts to distinguish between expected and unexpected changes in the Fed funds target rate and several indicators to distinguish between different phases of the business cycle. In line with the predictions of imperfect capital market theories, we find that yields on corporate bonds with low credit ratings widen (narrow) with respect to those with high credit ratings following an unexpected increase (decrease) in the Fed funds target rate during recession periods. Several tests suggest that our results are robust to outliers, potential endogeneity problems, empirical specification, control variables, countercyclical risk premium in futures, and alternative definitions of credit spreads and economic conditions.     

Historic Changes in the High Yield Bond Market

In a history that now stretches about four decades, the high yield (HY) market has experienced growth in issuance and out‐standings that is remarkable both for its level (about 13% per annum, with HY bonds now accounting for about 25% of the total corporate bond market) and its cyclicality and sensitivity to the broad economy. The HY market has also experienced a notable shift away from B‐rated bonds and toward both lower‐risk Ba‐rated bonds and, to a lesser extent, more risky Caa‐rated bonds. Consistent with this development, studies of the performance of HY bonds show Ba‐rated bonds experiencing not only lower risk, but also higher returns than Caa‐rated bonds, which have produced surprisingly low average returns along with exceptionally high volatility. At the same time, studies of the correlation of HY bond returns with returns on other major asset classes report that all classes of HY bonds (but particularly the riskier B‐ and Caa‐rated bonds) have consistently stronger relationships with common stocks (especially small‐cap stocks) than with Treasuries and investment‐grade bonds. Analysis of the volatility of HY bond returns over time shows that during periods of stability in the economy and financial markets, the volatility of HY bond returns has been very similar to that of investment‐grade bonds. But during periods of political or economic uncertainty, the volatility of HY bonds has become two or three times that of investment‐grade bonds, approaching the volatility of common stocks. The main driver of the significant increase in the risk of the aggregate HY bond market during periods of uncertainty has been Caa‐rated bonds, whose risk pattern has been remarkably similar to that of small‐cap common stocks. Analysis of the credit risk spread (or CRS) series for both the composite HY bond market and each of its rating categories shows markedly non‐normal distributions with significant positive “skewness”—that is, periods of exceptionally high spreads (that are not counterbalanced by periods of exceptionally low spreads). The authors also report a consistently strong relationship of the CRS series with default rates and the general state of the economy, with major peaks occurring during or shortly after economic recessions. Near the end of 2008, however, there was a clear break in this relationship when the CRS reached an historic peak of 2,000 basis points, or more than five standard deviations above its long‐term mean, while the default rate (at 4%) was below its long‐term average. The authors offer two explanations for this break in CRS‐default rate relationship: the jump in the CRS caused by the extreme flight to quality and drop in liquidity for all risky securities during the second half of 2008; and the use of covenant‐lite securities and other sources of financial flexibility that appear to have enabled many HY issuers to defer defaults (if not avoid them entirely).     

基于套利理论与ICIR模型的债券市场发行定价偏离研究

基于套利定价理论与利率期限结构理论,运用Tobit多元线性回归模型,得出债券发行定价的主要影响因素为债券无风险利率、债券期限溢价、债项信用评级、债券主体信用评级和债券赎回风险溢价,在此基础上再通过改进的CIR定价模型(ICIR)对2006～2010年各债券定价偏离现象进行研究的结果表明,在1%的显著性水平上,ICIR模型测算的债券理论价格通过了二级市场的定价检验,ICIR模型对债券发行定价偏离进行检验具有较强的合理性;同时,从发行年份来看,近五年来,债券定价偏离总体呈逐年下降趋势,债券发行定价与ICIR定价与二级市场定价逐步接轨,市场化程度越来越高。     

THE IMPACT OF SPLIT BOND RATINGS ON RISK PREMIA

Interest rates for bonds are negatively correlated with credit ratings assigned by agencies such as Moody's Investor Service and Standard & Poor's. Still in dispute is whether or not the ratings themselves convey information that is reflected in prices, hence interest rates in the bond markets. Disagreement between these two agencies' ratings leads to “split” ratings, and in this paper, the authors use the phenomenon of split ratings to assess whether or not ratings have a separate impact on bond prices. The results indicate that a downside split appears to have greater bond yield impact than an upside split. The findings are inconsistent with bond market efficiency, at least in the strong form. The market considers the quality of a split-rated bond to reflect the lower of the two ratings. Finally, the symmetry of the results with respect to the ratings agencies indicates that neither agency has more influence than the other in determining bond yields.     

The reinvestment risk premium in the valuation of British and Russian government bonds

This article studies the dynamic properties of the reinvestment risk premium in the UK and RF government bond markets. In a new interest rate environment when sovereign debt trades at a low and even negative yields and bond funds are struggling to earn sufficient returns, bond investors have become increasingly wary of reinvestment risk largely neglected previously. The reinvestment risk premium is quantified on the basis of replicating portfolios and further analyzed with respect to exposure to exogenous influence with the help of cointegration techniques. The findings are that in both markets investors recognize the significance of reinvestment risk. However, there are differences in the sensitivity of the reinvestment risk premium to exogenous indicators. In the UK government bond market investors tend to be guided by more conservative indicators but are ready to forecast in the medium-run; in the RF government bond market investors tend to be guided by less conservative indicators but are ready to forecast only in the short-run.     

A Comparison of Bond Ratings from Moody's S&P and Fitch IBCA

Previous research has found that the bond market values the ratings of Moody's and Standard & Poor's. This paper extends earlier research by comparing the ratings of Moody's, Standard and Poor's, and Fitch IBCA. The authors examine a very large database with monthly observations of bonds and bond ratings over a five‐year time period. The analysis focuses on comparing rating levels, rating changes, and the impact of ratings on bond yields. The results show that firms with publicly available Fitch IBCA ratings have higher ratings from Moody's and S&P than firms without Fitch IBCA ratings. The typical firm releasing a Fitch IBCA rating has a lower yield (controlling for Moody's and S&P rating), a more stable rating, and is more likely to receive an upgrade. For split‐rated bonds (Moody's vs. S&P), Fitch IBCA serves as a tiebreaker. This evidence is consistent with the bond market valuing the ratings of all three raters—Moody's, Standard & Poor's, and Fitch IBCA.