Investment and competition in unlicensed spectrum

Adding unlicensed spectrum, such as the recent opening of the television white spaces in the US, has the potential to benefit customers by increasing competition, but may also increase congestion. In an earlier paper, we studied this using models for price competition in congestible networks. Here we extend that model to include the investment costs of providers. With such costs, we characterize the equilibria of the resulting network investment and pricing game and show that in some cases the equilibrium is not increased competition but rather investment by a single monopolist.