Vague Notions in the Theory of Voting

Abstract

The social choice theory is well-known for its dramatic incompatibility results. We argue that these results are not very robust under plausible «perturbations» of their underlying assumptions. In particular, we give an overview of some results on probabilistic decision schemes and the aggregation of fuzzy preference relations. It turns out that with somewhat more vague basic concepts the theory of social choice can be of assistance in the design of good procedures for group decision making.