In this paper we present an axiomatic analysis of several ranking methods for tournaments. We find that two of them exhibit a very good behaviour with respect to the set of properties under consideration. One of them is the maximum likelihood ranking, the most common method in statistics and...

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>

We present a strategic game of pricing and targeted-advertising. Firms cansimultaneously target priceadvertisements to different groups of customers, or to the entiremarket. Pure strategy equilibria do not exist and thus marketsegmentation cannot occur surely. Equilibria exhibit random...

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>