Many economic and social situations can be represented by a digraph. Both axiomatic and iterativemethods to determine the strength or power of all the nodes in a digraph have been proposed inthe literature. We propose a new method, where the power of a node is determined by both thenumber of its...

Let X be a non-empty, compact, convex set in R and o an upper semi-continuous mapping from X to the collection of non-empty, compact, convex subsets of R;. It is well known that such a mapping has a stationary point on X, i.e. there exists a point in X satisfying that its image under o has a...