The paper analyzes spatial competition among firms that sell substitute and/or complementary products. The firms first choose locations on the perimeter of a circular city and then compete in quantities (à la Cournot). Both linear and convex (quadratic) transport costs are considered. In...

A government authority regulates an upstream monopolist only if there is a sufficient welfare increase to justify doing so. A downstream firm strategically increases costs in order to force regulation upstream. The decision to regulate increases profit downstream, reduces profit upstream and...