The VCG mechanism has some nice properties if the agents-are-substitutes property holds.For example, for combinatorial auctions the property assures that the VCG mechanism is supported by a pricing equilibrium. The existence of such a pricing equilibrium is a necessary condition for the...

The Nearest Neighbor classifier has shown to be a powerful tool for multiclass classification. In this note we explore both theoretical properties and empirical behavior of a variant of such method, in which the Nearest Neighbor rule is applied after selecting a set of so-called prototypes,...

In this paper we analyze equilibria in competitive environments under constraints across players'' strategies. This means that the action taken by one player limits the possible choices of the other players. In this context the classical approach, Kakutani''s Fixed Point theorem, does not work....