We prove the existence of symmetric pure Cournot equilibria with heterogeneous goods under the following condition: Each firm reacts to a rise in competitor's output in such a way that its market price does not rise.

We show that asymmetric equilibria may exist in an ex ante symmetric step-by-step R&D if product market competition is intense. The corresponding symmetric equilibrium is unstable and therefore less likely the one selected, while the asymmetric ones result in lower economic growth (reversing...

Regulators have long been aware of the social aspects of communication. In the past, regulated monopolists have provided Universal Service Obligations, typically funded via a system of cross-subsidies. In this paper, we first review the rationale for imposing Universal Service Obligations, based...

We analyze the impact of mandatory access on the infrastructure investments of two competing communications networks, and show that for low (high) access charges firms wait (preempt each other). Contrary to previous results, under preemption a higher access charge can delay first investment....

We analyze competition between vertically integrated infrastructure operators that provide access in different geographical areas. A regulator may impose a uniform access price, set local access rates, or deregulate access locally. We analyze the impact of these alternative regulatory regimes on...

Often, fixed-line incumbents also own the largest mobile network. We consider the effect of this joint ownership on market outcomes. Our model predicts that while fixed-to-mobile call prices to the integrated mobile network are more efficient than under separation, those to rival mobile networks...