Abstract
In the 1930s, socialist economists used the assumptions of equilibrium theory to argue that a central planner could coordinate supply and demand from above. This argument led Hayek, over the years, to try to explain the limitations of equilibrium theory and, conversely, to explain how capitalism functioned without the assumptions of equilibrium being met. In a changing world of agents who are ignorant of the future, how is a functioning market “order” possible? One answer can be found in Hayek's argument that evolved rules make people's future behavior more predictable and, more to the point, that they contain previously accumulated knowledge that provides the building blocks for future economic growth. Hayek's evolutionary theory was flawed, however, in failing to explain how people can know which rules are responsible for their success or failure so that they persist in using those rules and pass them forward in time. However, markets provide immediate feedback about success and failure through profits and losses. An evolutionary explanation of the economy would have permitted Hayek to dispense with the metaphor of general equilibrium, which was increasingly irrelevant to his understanding of economic order.