The theory of general economic equilibrium is surely one of the central achievements of modern economics. Although economists hold a wide range of views about the theory's usefulness as a guide to understanding or ameliorating the behavior of actual economies, its theorems and results concerning the efficiency of price-taking behavior in appropriately decentralized economic environments will no doubt continue to plague, perplex, or perhaps delight graduate students for years to come.The theory of general economic equilibrium is surely one of the central achievements of modern economics. Although economists hold a wide range of views about the theory's usefulness as a guide to understanding or ameliorating the behavior of actual economies, its theorems and results concerning the efficiency of price-taking behavior in appropriately decentralized economic environments will no doubt continue to plague, perplex, or perhaps delight graduate students for years to come.