In a recent article in this journal [6], Clement G. Krouse and Wayne Y. Lee (hereafter K-L) presented a model of optimal equity financing of a corporation based on Pontryagin's maximum principle. In this note the basic assumption of a constant internal rate of return of the K-L model is relaxed. As a result, the financial implications of the K-L results remain essentially unchanged, but their applicability is extended considerably, and some undesirable solution characteristics are eliminated.

Three important methods exist for the treatment of risk in capital budgeting problems: the certainty equivalent method (CE), the risk-adjusted discount method (RAD), and the probability distribution or Hillier-Hertz approach (PD, based on [4]). Each one of these methods evaluates the multiperiod stream of risky returns generated by an investment for given distributions of the returns in each period. A common assumption for all three methods is the certainty of the occurrence of a given risky cash inflow (defined by its distribution) in a given time period. This assumption is probably derived from accounting practices. In references [8] and [9] the PD approach was generalized by removing the certain timing assumption. This paper examines the implications of random timing of cash returns within the framework of the better known CE method.

In a series of recent articles ([2], [3], [4], [5]) R. B. Porter and his associates have conducted empirical comparisons of the Mean-Variance (EV) and Stochastic Dominance portfolio choice criteria. The basic methodology of all these studies was first to compute the set of EV-efficient portfolios by an optimizing algorithm, then to find through heuristic methods “stochastically dominant” portfolios, and finally to compare the two. A major finding of these studies was that most EV-efficient portfolios survived the second-degree stochastic dominance (SSD) test against the randomly generated portfolios. The purpose of this note is to show that, for all cases of practical interest, a portion of the EV frontier is a subset of the SSD-efficient set. In other words, we offer here an exact theoretical justification of some empirical results of the aforementioned studies.