5. IRV could increase voter participation
The reasoning for why IRV might increase voter participation runs like this: Some potential voters may feel that there are no candidates on the ballot that they can really get excited about -- so they donít bother voting. Since IRV eliminates the problem of multiple candidates splitting the vote and throwing the race to least preferred candidates, more candidates, representing a broader range of views, will feel free to run. While IRV will not enhance the chances of a candidate with marginal support to win, it may encourage greater voter participation since some refrainers may feel they have a candidate to enthusiastically support with their first-choice vote.
All of the nations that use IRV have far higher levels of voter participation than does the United States. However, there are so many other contrasting factors involved that no causal relationship can be assumed.
The mayoral elections in Ann Arbor, Michigan during the 1970's provide clearer evidence of the potential impact of IRV. In terms of voter turnout, the relevant factor is whether an election has only two credible contenders or more (which IRV accommodates). In 1971 and 1977 there were only two candidates running for Mayor and the average turnout was 24,401. In 1973 and in 1975 (the one election with IRV) the Human Rights Party joined the Democrats and Republicans in the mayoral races and the average voter turnout was 31,190 -- 28% higher.
Mock elections using IRV were conducted at eight Vermont schools. Among high school students who participated, 46% said the use of IRV would make them more likely to vote after they turn eighteen and only 1% said it would make them less likely to vote.