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...

A "folk theorem" originating, among others, in the work of Stiglitz maintains that competitive equilibria area always or "generically" inefficient (unless contracts directly specify consumption levels as in Prescott and Townsend, thus bypassing trading in anonymous markets). This paper...

We develop a theoretical model of security investments in a network of interconnected agents. Network connections introduce the possibility of cascading failures, due to an exogenous or endogenous attack, depending on the profile of security investments by the agents. The general presumption in...

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...

We extend the basic Schumpeterian endogenous growth model by allowing incumbents to undertake innovations to improve their products, while entrants engage in more “radical” innovations to replace incumbents. Our model provides a tractable framework for the analysis of growth driven by both...

We develop a microeconomic model of endogenous growth where clean and dirty technologies compete in production and innovation. in the sense that research can be directed to either clean or dirty technologies. If dirty technologies are more advanced to start with, the potential transition to...