ON THE INVARIANCE OF A MEAN VOTER THEOREM

Under the assumption that preferences can be represented by linear-in- parameters utility functions, Caplin and Nalebuff (Econometrica 59 (19 91), 1-23) have demonstrated that in a super-majority voting problem, the mean voter's choice is unbeatable according to a rule that depends on the distribution and dimensionality of voters' preferences. We sho w in some cases that the mean voter and the social choice, as well as this rule, are not invariant with respect to transformations of the pa rameters of the utility functions that preserve the voters' ordinal pr eferences. Journal of Economic Literature Classification Number D71. ( C) 1995 Academic Press, Inc.