Normative theories in finance center around investment decisions under certainty and uncertainty. These theories provide rules for accepting or rejecting investment projects which may yield cash proceeds in the future. However, the question of optimal duration of an investment, that is, when to terminate a given investment, has received very little attention in the literature. Works dealing with the duration problem usually refer to the classical examples:' when to harvest a forest (cut a tree), when to bottle an aging wine, etc. With the exception of Kaplan (1972), the few published works dealing with this problem (the most recent of which are Bierman [1968], Hirshleifer [1970], and Hartman [1976]) assume certainty.2 Kaplan (1972), following Karlin (1962), relaxed the assumption that the increase in the value of the growth asset is deterministic. He used dynamic programming techniques to compute the optimal policy when the increase in This paper deals with the optimal duration of stochastic growth investments (e.g., when to harvest a forest, when to bottle an aging wine, etc.). We show that, when uncertainty increases, a risk-neutral investor will wait for higher offers to come along before he sells his investment. However, the expected duration will not necessarily increase. Under the traditional definitions of increasing risk, these results will not apply to risk averters. We show, however, that under some recent definitions of increasing risk the above results apply to risk averters too. Since the structure of our problem resembles a search problem, similar results are also applicable to the case of search, where the prospects of the object of search are stochastically growing over time and are subject to stochastic cyclical fluctuations. * We would like to thank the referees of this Journal for their helpful comments and suggestions. 1. Hirshleifer (1970) notes that this problem was treated as early as 1891 by Bohm-Bawerk. 2. It is interesting to note the existence of a vast literature in agricultural economics dealing with the issue of optimal duration of timber under certainty (a famous one is Gaffney [1975]). Some works, however, deal with uncertainty (e.g., Lembersky and Johnson 1975), but they use a different framework and do not derive the properties of the solution.