This paper illustrates the effect of market size on the decision of whether or not firms should vertically integrate or disintegrate. We use a model of two successive stages of production with Cournot competition in each stage. In this model, firms choose to specialize (either upstream or...

This paper provides a novel rationale for the regulation of market size when heterogeneous firms compete. A regulator seeks to maximize total welfare by choosing the number of firms allowed to enter the market, e.g. by issuing a certain number of licenses. Opening up the market for more firms...