The impact of junior debt issuance on senior unsecured debt's risk premiums

Numerous studies have examined the impact of security issuance upon the value of pre-existing debt and equity but the focus has largely been on changes in equity value. We examine changes in senior unsecured debt risk premiums that accompany new junior debt issues. Additionally, we test several hypotheses regarding the potential impacts of junior debt issues. Extant theory suggests senior debt value may be threatened under certain conditions by the issuance of junior debt. Our results indicate that when junior debt replaces bank debt, senior default risk premiums experience abnormal declines. The result is broadly consistent with the elevation of the senior unsecured debt by way of the elimination of a separate and more senior class of debt claimants. In contrast, we also find that larger junior bond issues are associated with abnormal increases in senior risk premiums, broadly consistent with issue size being correlated with negative information about firm cash flows. We find strong evidence of interaction effects. For example, replacement of bank debt results in greater changes in default risk premiums the larger the issue size. We also find lower credit ratings magnify other effects. For example, if the junior debt issued matures before the outstanding senior unsecured bond, senior risk premiums experience abnormal increases for lower rated debt.