In this paper we examine the effect of convertible debt on the investm
ent incentives facing stockholders. The effect depends critically on t
he value of existing assets relative to the firm's investment requirem
ents. With a restrictive dividend covenant, convertible debt mitigates
the overinvestment incentive associated with risky debt but exacerbat
es the underinvestment incentive at higher values of existing assets.
A less-restrictive dividend covenant exacerbates overinvestment under
straight debt financing but reduces the underinvestment incentive indu
ced by the conversion feature. In this context, a convertible debt con
tract with a less-restrictive dividend covenant maximizes firm value.