In this paper we argue that two important causes of welfare losses in oligopolistic markets have been neglected. We show that in models where location is endogenous, welfare losses arising from wrong locations or from lack of market coverage may be substantial despite firms competing in prices....

We study the percentage of welfare losses (PWL) yielded by imperfect competition under product differentiation. When demand is linear, even if prices, outputs, costs and the number of firms can be observed, PWL is arbitrary in both Cournot and Bertrand equilibria. If in addition the elasticity...

We study the impact of investment on employment. In the short-run an increase in investment stimulates employment (this is the standard Keynesian multiplier). However increases of investment translate into increases in the capital stock. If labor and capital are substitutes (resp. complements),...

Suppose that a group of individuals owns collectively a technology which produces a consumption good by means of a (possibly heterogeneous) input. A sharing rule associates input contributions with a vector of consumptions that are technologically feasible. We show that the set of allocations...

We study the impact of investment on employment. In the short-run an increase in investment stimulates employment (this is the standard Keynesian multiplier). However increases of investment translate into increases in the capital stock. If labor and capital are substitutes (resp. complements),...

In this paper we study mediation when two countries might fight a war over the ownership of a resource. Under complete information mediation is always successful, but a little bit of asymmetric information or some imperfect observability may render mediation impossible

We study the possibility of peace when two countries fight a war over the ownership of a resource. War is always the outcome of the game played by rational countries – under complete or asymmetric information – when there is no pre-established distribution of the resource among countries....

We characterize the sharing rule for which a contribution mechanism achieves efficiency in a cooperative production setting when agents are heterogeneous. The sharing rule bears no resemblance to those considered by the previous literature. We also show for a large class of sharing rules that if...