A time-varying common risk factor affecting corporate yield spreads

A time-varying common risk factor affecting corporate yield spreads is modelled by extending a panel data model. The panel data model accommodates a common factor, which is associated with time-varying individual effects. The factor multiplied by a bond-specific unobservable is identified as a systematic risk premium. In disentangling the systematic risk premium, both credit and liquidity risks are evaluated; the credit risk is assessed by bond rating, and the liquidity risk is indirectly measured by discrepancy in quoted yields by brokerage firms. Parameters are estimated by the generalized method of moments procedure. The model is tested on the corporate bond market in Japan. Empirical results show that the time-varying common risk factor is successfully estimated together with credit and liquidity risks.