The fall of Wall Street is for market fundamentalism what the fall of the Berlin Wall was for communism. - Joseph E. Stiglitz

The standard neoclassical model the formal articulation of Adam Smith's invisible hand, the contention that market economies will ensure economic efficiency provides little guidance for the choice of economic systems, since once information imperfections (and the fact that markets are incomplete) are brought into the analysis, as surely they must be, there is no presumption that markets are efficient.

It's actually a tribute to the quality of economics teaching that they have persuaded so many generations of students to believe in so much that seems so counter to what the world is like. Many of the things that I'm going to describe make so much more common sense than these notions that seem counter to what ones eyes see every day.

At the core of the failure of the socialist experiment is not just the lack of property rights. Equally important were the problems arising from lack of incentives and competition, not only in the sphere of economics but also in politics. Even more important perhaps were problems of information. Hayek was right, of course, in emphasizing that the information problems facing a central planner were overwhelming. I am not sure that Hayek fully appreciated the range of information problems. If they were limited to the kinds of information problems that are at the center of the Arrow-Debreu model consumers conveying their preferences to firms, and scarcity values being communicated both to firms and consumers then market socialism would have worked. Lange would have been correct that by using prices, the socialist economy could "solve" the information problem just as well as the market could. But problems of information are broader.