Hypergraph formation game

We define a hypergraph by a set of associations which consist of nonexclusive two or more players. It is a generalization of a graph (or a network) in the sense that an association, the counterpart of a link in a hypergraph, connects any number of nodes, not simply a pair of nodes. We characterize the efficient hypergraphs and stable hypergraphs for the linear variable cost of associations. The efficient hypergraph is either the empty hypergraph or the grand hypergraph consisting of a single grand association. The stable hypergraph can be a grand hypergraph, a star hypergraph or a line hypergraph. If a star hypergraph is stable, it must have a singleton center. Generally, a hypergraph can be underconnected, but cannot be overconnected.