Team Tennis competitions produce aggregate scores for teams, and thus team rankings, based on head-to-head matchups of individual team members. Similar scoring rules can be used to rank any two groups that must be compared on the basis of paired elements. We explore such rules in terms of their...

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...