This discussion paper led to a publication in 'Social Choice and Welfare', 2005, 24, 439-454.<P> 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...</p>

This discussion paper led to an article in <I>Games and Economic Behavior</I> (2012), pp. 120-138.<P> We consider an oligopolistic market where firms compete in price and quality and where consumers are heterogeneous in knowledge: some consumers know both the prices and quality of the products offered,...</p></i>

We modify the paper of Stahl (1989) [Stahl, D.O., 1989. Oligopolistic pricing with sequential consumer search. American Economic Review 79, 700–12] by relaxing the assumption that consumers obtain the first price quotation for free. When all price quotations are costly to obtain, the unique...