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...

The problem of collective action is usually identified with social dilemmas. A wider notion of the term collective action problem is introduced, as dilemmas are not the only problems to arise in collective action. The article first presents a typology of collective action problems based on...