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 resulted in a publication in the 'SIAM Journal on Optimization', 2007, 18, 290-308. <P> In this paper we present two general results on the existence of a discrete zero point of a function from the n-dimensional integer lattice Zn to the n-dimensional Euclidean space Rn. Under...</p>

This discussion paper resulted in a publication in 'Mathematical Programming', ser. A, 2006, 108, 127-134. <P>

This paper deals with the optimal provision of infrastructure by means of public-private partnership contracts. Inthe economic literature infrastructure is characterized as a large, indivisible and non-rival capital good thatproduces services for its users. The non-rivalness or nonexcludability...

This discussion paper resulted in a publication in 'Games and Economic Behavior', 2007, 59, 85-104. <P> We consider cooperative games with transferable utility (TU-games), in which we allow for a social structure on the set of players. The social structure is utilized to refine the core of the...</p>

This discussion paper resulted in a publication in the 'Journal of Optimization Theory and Applications', 2010, 144, 391-407. <p> Tucker's well-known combinatorial lemma states that for any given symmetric triangulation of the n-dimensional unit cube and for any integer labeling that assigns to...</p>

In a standard general equilibrium model it is assumed that there are no price restictionsand that prices adjust infinitely fast to their equilibrium values. In this paper the set ofadmissible prices is allowed to be an arbitrary convex set. For such an arbitrary set it cannotbe guaranteed that...

Any function from a non-empty polytope into itself that is locally gross direction preserving is shown to have the fixed point property. Brouwer's fixed point theorem for continuous functions is a special case. We discuss the application of the result in the area of non-cooperative game...</p>

We study the existence problem of a zero point of a function defined on a finite set of elements of the integer lattice of the n-dimensional Euclidean space. It is assumed that the set is integrally convex, which implies that the convex hull of the set can be subdivided in simplices such that...

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