Given a bond and a stock issued by the same issuer, what is the appropriate ratio of bond-to-stock one should hold in order to minimize the specific risk to that issuer? Equivalently, what is the expected change in the credit spread for a given change in equity? Knowing this, one could then use the spread duration, or credit DV01, to derive the expected price change of the bond, which could be used as the hedge ratio.
I am looking for professional or academic research that may inform the decision of how much equity to short against a given bond or credit default swap. Any research that cites a correlation or regression coefficient between equity and credit spreads (could be OAS or CDS-equivalent spreads) would be helpful.