This paper develops an econometric model of industry dynamics for concentrated markets that can be estimated very quickly from market-level panel data on the number of producers and consumers using a nested fixed-point algorithm. We show that the model has an essentially unique symmetric...

The paper proves that (static) non cooperative foreclosing or collusive equilibria in the upstream roaming market are sustainable even if there exist more incumbents. In particular we focus on the complementarity that occurs when an incumbent upstream signs a roaming agreement with a new...

This Chapter reviews the theoretical literature on entry games and free entry equilibria. We show that a wide range of symmetric oligopoly models share common comparative statics properties. Individual profits and quantities decrease in the number of firms, and tend to competitive or...