In this paper, I examine duopoly with multi-services, where firms offer delivery prices and mill prices at the same time, and each consumer chooses one of them. In the equilibria, firms specialize in delivery services even if their transport costs are higher than consumers'. This result is...

We characterize the equilibrium behavior in a broad class of competition models in which the competing firms' market shares are given by an attraction model, and the aggregate sales in the industry depend on the aggregate attraction value according to a general function. Each firm's revenues and...