Plans for the development of high speed railways lines (HSR) in Spain are widespread. At the beginning of 2010 four HSR lines were operating in routes where the air transport mode used to be dominant. In this paper we examine through econometric means the air carriers' reaction to these HSR...

According to static models of industrial organization, a rise in competition decreases prices. In this paper, I test whether this conclusion can be reversed in the mobile telecommunications markets where dynamic efficiency effects might be significant. The empirical test relies on the change in...

We propose a general model of monopolistic competition, which encompasses existing models while being flexible enough to take into account new demand and competition features. Using the concept of Frechet differentiability, we determine a general demand system. The basic tool we use to study the...

We develop a model of a city populated by heterogeneous agents. Agents self-select into entrepreneurship, and entrepreneurs set up firms which hire workers. We characterize the equilibrium matching between firms and workers, as well as the within-city assignment of agents to locations. We then...

We develop a monopolistic-competition model of closed two-sector one-factor economy, where agents are (continuously) heterogeneous in their entrepreneurship abilities and choose between being employees or entrepreneurs. The sufficient conditions in terms of variable elasticity of substitution...

This paper estimates the effects of airports on economic growth in US metropolitan areas. The estimation uses a novel technique to identify the effects of changes in local airport sizes from overall changes in the air travel network. Airport size is found to have a positive effect on local...