Local Infrastructures and Externalities: Does the Size Matter?

We setup a model in which the residents of two neighboring municipalities can use the services provided by public infrastructures located in both jurisdictions. If services are either complements or substitutes in use, the municipalities strategically interact when investing in infrastructures; moreover, when they differ in population size, the small municipality reacts more to the expenditure of its neighbor than the big one. The theoretical predictions are then tested by estimating the determinants of the stock of public infrastructures of the municipalities belonging to the Autonomous Province of Trento, in Italy.