l.ehlerske.unimaas.nl

Collective decision problems are considered with a finite number of agents who have single-peaked preferences on the real line. A probabilistic decision scheme assigns a probability distribution over the real line to every profile of reported preferences. The main result of the paper is a characterization of the class of unani-mous and strategy-proof probabilistic schemes with the aid of fixed probability dis-tributions that play a role similar to that of the phantom voters in H. Mouli