All the stock price models discussed in this paper are based on the assumption that the present value of a share of common stock is equal to the discounted value of all future expected dividends accruing to the stockholder:where Po : current value of a share of common stock, Dt: dividend expected to be received at end of period t, k : investor's discount or time-value rate, andt : time.

There is broad consensus that three types of risk confront the potential bond purchaser: the risk of default (possible interest and/or principal loss), the risk of interest rate changes (possible principal loss or gain if the bonds are sold before maturity), and price level risk (loss of purchasing power). The analysis in this paper is directed toward the first of these risks, the risk of default. By assuming that investors require interest rate adjustments on debt subject to default sufficient to give them an expected present value equal to the present value associated with the investment of their funds in default-free securities, we examine the process that determines the risk-adjusted equilibrium interest rate and the factors affecting that rate. We also examine the implications of the model for the cost of debt and a firm's debt capacity.

In a previous paper we reviewed the literature on normative stock price models. These models specified the present value of a share of common stock to be equal to the discounted value of dividends accruing to the holder. Using continuous discounting, the present value of a share is (1) where Dt is the dividend rate at time t and k is the cost of equity capital. Presumably k is a function of both the stockholders' time value of money and the perceived risk or uncertainty associated with the future dividend stream.