Experimental or precautionary? Adaptive management over a range of time horizons

摘要: Many studies of adaptive harvest management already exist in the literature, but most (if not all) use long, sometimes infinite, time horizons. Such long-term objectives provide an opportunity to manage experimentally, so that poorly understood dynamics are learned and any returns sacrificed for experimentation repaid by improved over remaining horizon. However, a manager is unlikely weight outcomes distant future equally against present. Furthermore, appropriate model system may remain constant time-frame required experiment, learn improve management. In these cases discounting and/or finite horizon fit manager's assumptions goals more effectively, value likely be diminished. this paper we construct simple hypothetical population compare optimal passive active strategies range This allows us determine level short-, medium- goals. We discover strategy precautionary short medium horizons, rather than experimental. That is, action with known moderate benefits preferred uncertain marginally larger expected benefits. runs counter widespread assumption literature incorporating learning into optimization will encourage experimentation. Synthesis applications. The general results have potential application environmental problem where might applied; example, conservation, pest control, harvesting water flows. examine horizons reflect variety possible assumptions. Our example demonstrates face uncertainty, maximizes does necessarily include deliberate learning. Optimal weighs all its consequences, can yield approach.