Firms have two motivations for issuing convertible debt. Some issue convertible debt instead of straight debt to mitigate the costs of bondholder/stockholder agency conflicts. Others issue convertible debt instead of common debt to reduce the costs of adverse selection.

There are now two dominant theories of convertible debt held by academic economists. One theory which has been called the "risk-shifting" hypothesis-effectively views convertibles as an alternative to straight debt. The second-known as the "sig-nalling" (or "backdoor-equity") theory-treats...