This chapter surveys empirical models of market structure. We pay particular attention to equilibrium models that interpret cross-sectional variation in the number of firms or firm turnover rates. We begin by discussing what economists can in principle learn from models with homogeneous...

Computer automation has the potential, just starting to be realized, of transforming the design and operation of markets, and the behaviors of agents trading in them. We discuss the possibilities for automating markets, presenting a broad conceptual framework covering resource allocation as well...