In spatial environments we consider social welfare functions satisfying Arrow's requirements, i.e. weak Pareto and independence of irrelevant alternatives. Individual preferences measure distances between alternatives according to the lp-norm (for a fixed 1=p=[infinity]). When the policy space...

We consider the problem of efficiently sharing water from a river among a group of satiable agents. Since each agent's benefit function exhibits a satiation point, the environment can be described as a cooperative game with externalities. We show that the downstream incremental distribution is...

In one-dimensional environments with single-peaked preferences we consider social welfare functions satisfying Arrow's requirements, i.e. weak Pareto and independence of irrelevant alternatives. When the policy space is a one-dimensional continuum such a welfare function is determined by a...

A desirable property of a voting procedure is that it be immune to the strategic withdrawal of a cadidate for election. Dutta, Jackson, and Le Breton (Econometrica,2001) have established a number of theorems which demonstrate that this condition is incompatible with some other desirable...

We study the problem of assigning indivisible and heterogenous objects (e.g., houses, jobs, offices, school or university admissions etc.) to agents. Each agent receives at most one object and monetary compensations are not possible. We consider mechanisms satisfying a set of basic properties...

We consider general allocation problems with indivisibilities where agents' preferences possibly exhibit externalities. In such contexts many different core notions were proposed. One is the -core whereby blocking is only allowed via allocations where the non-blocking agents receive their...