Network Investment and Competition with Access-to-Bypass

This paper examines firms' incentive to make irreversible investments under an open access policy with stochastically growing demand. Using a simple model, we derive an access-to-bypass equilibrium. Analysis of the equilibrium confirms that the introduction of competition in network industries makes a firm's incentive to make investments greater than those of a monopolist. We then show that a change in access charges induces a trade-off in social welfare. That is, a decrease in the access charge expands a social benefit flow in the access duopoly, and deters not only the introduction of a new network facility, but also a positive network externality generated by the construction of an additional bypass network. The feasibility of the socially optimal investment timing is then discussed