This Paper develops a model in which the interaction between product market imperfections, transportation costs, unions and workers immobility across regions creates a tendency for agglomeration of firms when transportation costs are low. The model fits quite well the European experience. It is...

In the Dixit-Stiglitz model of monopolistic competition, entry of firms is socially too small. Other authors have shown that excess entry is also a possibility with other preferences for diversity. We show that the cost structure and workers's rents can also explain excess entry.

Two types of agents interact on a pre-existing free platform. Agents value positively the presence of agents of the other type but may value negatively the presence of agents of their own type. We ask whether a new platform can find fees and subsidies so as to divert agents from the existing...

This paper analyses the evolution of employment in the Belgian provinces during the period 1974-92. It identifies provincial, industrial and temporal effects. This allows us to construct a 'virtual' employment series by filtering out provincial effects. A comparison with actual employment...