Efficacy of Vote in Multi-Seats Election

Abstract

We examined efficacy of vote in multi-seats elections. Efficacy of vote has been calculated for single seat elections and several ways of calculation have been proposed. However, research for the multi-seats elections is far behind. We made general considerations for the voters in multi-seats elections. Multi-seats elections request new ideas for the analysis. Especially, we concluded that the assumption that voters have utilities on the combination of winners than the independent winners is suitable. Under this assumption we calculated the efficacy for the two-seats three-candidates case with the simplest method of multinomial distribution model. We find that a vote is more effective in two-seats three-candidates case than in one-seat two-candidates case. We also find that among two-seats three-candidates elections limited vote system (one vote for one voter) is as effective as bloc vote system (two votes for one voter). © 1994, Japanese Association For Mathematical Sociology. All rights reserved.