Abstract
Using Bank of America/Merrill Lynch bond yield indexes, we compare the returns on investment-grade bonds to the returns on high-yield bonds over the period from January 1997 through mid-August 2011, a period marked by the collapse of the technology sector in early 2000 and the financial crisis in 2008. We compare return and risk measures under the assumption of a normal distribution with those obtained under the assumption of a stable distribution. When a normal distribution is assumed, we see a higher expected return associated with a lower SD on the high-yield bond returns relative to investment-grade bond returns. However, we also find that the returns on both high-yield bonds and investment-grade bonds exhibit stable (fat-tailed) distributions, with the fat tail more pronounced for the high-yield bond series. These results suggest that the assumption of a distribution that allows for fat tails and skewness is important for identifying the risk and return characteristics of these bond series.
Acknowledgement
The authors are grateful to John Nolan for permission to use the software STABLE for Windows in their research. www.RobustAnalysis.com.