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Introduction

Voting theorists have long been aware that it is not always in the best interest of voters to vote for their most sincerely preferred candidates. Voting schemes in which voters can obtain a more preferred outcome by voting strategically rather than sincerely are dubbed manipulable. And it has been well established that most voting schemes used in elections with three or more alternatives (including all reasonably ``attractive'' voting schemes previously investigated) are manipulable [1,11,12,21]. On the other hand, there are well-known systems that rely on randomness to elicit sincere voting behavior [1]; however, the arbitrariness present in such systems renders them generally unacceptable to voting populations.

Studies have shown empirical evidence that voting systems are manipulated by voters in real elections. Brams and Merrill [5] analyzed data collected in the 1992 National Election Study and estimated that 34.5 percent of Perot supporters did not vote sincerely in the 1992 Presidential election because they felt they could make better use of their votes by voting for their second-choice candidates. Cain [6] developed a model of strategic voting in the British electorate that suggests strategic manipulation does occur, especially when voters want to avoid ``wasting'' their votes or when the race is only close between two of the parties in a three party election. And Black [3] analyzed data from the 1968 and 1972 Canadian Federal elections and estimated that 12 percent of the voters in these elections voted for their second-choice party. It is difficult to determine how many of the voters participating in the analyzed elections voted sincerely even though they could have benefited from voting strategically. And it is uncertain whether these sincere voters voted sincerely out of ignorance of the preferences of others, ignorance of how to use preference information to their best advantage, a desire to show support for an underdog candidate, or a belief that insincere voting is dishonest.

In this paper we will examine some of the problems that may arise when voters use information about the preferences of other voters to manipulate an election. We will then sketch an information-neutral voting system that would minimize the possibilities for such manipulation while relying minimally on chance. This system allows voters to optimize their votes without knowledge of the preferences of others. It also improves analysts' abilities to interpret election results accurately.



next up previous
Next: Background and Motivation Up: Towards an Information-Neutral Previous: Towards an Information-Neutral



Lorrie Faith Cranor
Thu Apr 25 14:31:14 CDT 1996