Building on a model of the interaction of risk-averse frms that compete in forward and spot markets, we develop an empirical strategy to test whether oligopolistic frms use forward contracts for strategic motives, for risk-hedging, or for both. An increase in the number of players weakens the...

See also the article 'Mean and bold: on separating merger economies from structural efficiency gains in the drinking water sector' 2010, <I>The Journal of the Operational Research Society</I>, 61, 222-34.<P> The Dutch drinking water sector experienced two drastic changes over the last 10 years. Firstly,...</p></i>

This discussion paper resulted in a publication in 'Siberian Advances in Mathematics', 2002, 12, 97-125.<P> A cooperative game with transferable utilities, or simply aTU-game, describes a situation in which players can obtain certainpayoffs by cooperation. A solution mapping for these games is...</p>

We consider cooperative transferable utility games, or simply TU-games, with a limited communication structure in which players can cooperate if and only if they are connected in the communication graph. A difference between the restricted Banzhaf value and the Myerson value (i.e. the Shapley...

Recently, applications of cooperative game theory to economic allocation problems have gained popularity. In many such allocation problems, such as river games, queueing games and auction games, the game is totally positive (i.e., all dividends are nonnegative), and there is some hierarchical...

This discussion paper resulted in a publication in 'Economics Letters', 2012, 117, 786-789.<P> We introduce an efficient solution for games with communication graph structures and show that it is characterized by efficiency, fairness and a new axiom called component balancedness. This latter axiom...</p>

Agents participating in different kind of organizations, usually take different positions in some relational structure. The aim of this paper is to introduce a new framework taking into account both communication and hierachical features derived from this participation. In fact, this new set or...

In a river claims problem, agents are ordered linearly, and they have both an initial water endowment as well as a claim to the total water resource. We provide characterizations of two solutions to this problem, using Composition properties which have particularly relevant interpretations for...

See also the publication in 'Journal of Mathematical Economics', 2008, 44, 1114-1125. <P> In this paper we describe the extreme points of two closely related polytopes that are assigned to a digraph. The first polytope is the set of all sharing vectors (elements from the unit simplex) such that...</p>

This discussion paper resulted in a publication in the 'European Journal of Operational Research', 2013, 224, 167-179.<P> In a standard TU-game it is assumed that every subset of the player set can form a coalition and earn its worth. One of the first models where restrictions in cooperation are...</p>