Fisheries worldwide are subject to economic mismanagement of major proportions. Although most commercial fish stocks are capable of yielding high net profits (rents), only a relatively few fisheries are actually profitable. Rough estimates suggest that on a global scale, the loss of net economic benefits due to mismanagement of fisheries may easily amount to 50% or more of the global landed value of some 100 billion US$ annually. The fisheries problem derives fundamentally from inappropriate social institutions controlling the fishing activity, the foremost of which is the common property arrangement. Fisheries management consists of replacing these institutions with more appropriate ones and, within that framework, setting the correct parameters over time. Global evidence suggests that the cost of fisheries management often constitutes a substantial fraction of the value of the harvest. A part of the fisheries management problem, therefore, is to strike the right balance between the efficacy of the fisheries management regime and the cost of operating it.