We study the efficiency of oligopoly equilibria in congested markets. The motivating examples are the allocation of network flows in a communication network or of traffic in a transportation network. We show that increasing competition among oligopolists can reduce efficiency, measured as the...

We study the efficiency properties of oligopoly equilibria in congested networks. Our measure of efficiency is the difference between users' willingness to pay and delay costs. Previous work has demonstrated that in networks consisting of parallel links, efficiency losses from competition are...