Chapter 51 Coordination Failure in Market Statistic Games A central question in economics is how do markets coordinate the behavior of anonymous decision makers in a many person decentralized economy. Economic theory has traditionally addressed the question using the equilibrium method which abstracts away from an important aspect of the general coordination problem because it assumes an equilibrium. For abstract games an equilibrium is defined as an assignment to each player of a strategy that is best for him when the others use the strategies assigned to them. The relevance of this abstract mutual consistency requirement for economic modeling is an open question. The requirement has two related problems: disequilibrium and coordination failure. First the mutual consistency requirement of an equilibrium assignment is not an implication of individual rationality but an additional strong assumption. Second there is often more than one equilibrium assignment. For example multiple Pareto ranked equilibria arise in both macroeconomic models with production search or trading externalities and microeconomic models of monopolistic competition technology adoption and diffusion and manufacturing with non convexities.