TROPHIC PORTFOLIOS IN MARINE FISHERIES: A STEP TOWARDS ECOSYSTEM MANAGEMENT

Marine ecologists warn that humans are "fishing down marine food webs." To explore the economic implications of this phenomenon, this paper applies portfolio theory to aggregate fisheries data. It poses two definitions of a sustainable mean-variance catch frontier. It computes a mean-variance frontier for catch using UNFAO historical fisheries data. Finally, the paper discusses the historical trend in inefficiency