A continuous rating method for preferential voting. The incomplete case

Abstract

A method is given for quantitatively rating the social acceptance of different options which are the matter of a preferential vote. In contrast to a previous article, here the individual votes are allowed to be incomplete, that is, they need not express a comparison between every pair of options. This includes the case where each voter gives an ordered list restricted to a subset of most preferred options. In this connection, the proposed method (except for one of the given variants) carefully distinguishes a lack of information about a given pair of options from a proper tie between them. As in the special case of complete individual votes, the proposed generalization is proved to have certain desirable properties, which include: the continuity of the rates with respect to the data, a decomposition property that characterizes certain situations opposite to a tie, the Condorcet-Smith principle, and clone consistency