The forgotten decision rules: Majority rules based on difference of votes

Producción CientíficaIn this paper we point out some interesting properties of a class of decision rules located between simple and unanimous majorities. These majority rules are based on difference of votes: an alternative wins when the difference between the number of votes obtained by this alternative and that obtained by the other is greater than a previously fixed quantity. We also give some characterizations of these majority rules by means of two properties well known in the literature: cancellation and decisiveness.Ministerio de Ciencia y Tecnología (Project MTM2005-08982-C04-02)Junta de Castilla y León (Consejería de Educación y Cultura, Project VA040A05