We examine Bertrand competition with non-rigid capacity constraints, demonstrating that the set of pure strategy Nash equilibrium constitutes an interval. We then examine the properties of this set as (a) the number of firms becomes large and (b) the capacity cost increases.

We examine a simple model of collusion under a single-object second-price auction. Under the appropriate parameter conditions, in particular as long as collusion is neither too easy, nor too difficult, we find that the optimal policy involves both an effective ceiling, as well as a reserve price...