Preferences,choices, tournaments: Alternative foundations for the evaluation of voting schemes

The standard assumption underlying most of the negative results of the social choice theory is that the individuals have complete and transitive preference relations over the candidates. As an alternative to this assumption we consider the possibility that individuals can be characterized as possessing preference tournaments (i.e. asymmetric and complete relations) over the candidate set. We discuss the implications of the latter assumption to the negative results of social choice theory. Finally some solution concepts applicable in the individual preference tournament framework are outlined.