This thread is getting consistently hijacked over the issue, so let’s pick it up here.
At present, the U.S. and most other democracies elect a single officer (“single” must be emphasized – alternative systems for electing multimember policymaking assemblies, such as proportional representation, are a different discussion) by giving the office to whichever candidate won a plurality of the votes cast, i.e., more than any other candidate but not necessarily 50%+1. (Some jurisdictions vary this by requiring a majority and holding a runoff election between the top two finishers – but a second election costs the government more money.) This naturally and strongly discourages third-party candidates – i.e. a third-party (or independent nopartisan) candidate cannot hope even to get the votes of all voters who want him/her to win, because they are afraid of “wasting” their votes. Worse yet, it creates a “spoiler” problem. Suppose it’s 2000 and your favorite presidential candidate in the race is Pat Buchanan (Reform). If so, almost certainly your second choice is George Bush; but you really, really prefer Buchanan; but you really, really, really oppose Al Gore. That means if you vote or, worse yet, volunteer for Buchan, you are “splitting the opposition” to Gore, taking votes away from Bush that he otherwise would have gotten, and making it more likely Gore will win. So, in effect, a vote (or donation of time and/or money) for Buchanan is a vote (or, etc.) for Gore. Likewise, a vote for Ralph Nader (Green) is a vote for Bush. Third-party candidates keep denying this logic – I remember a button from 1980, “A VOTE FOR ANDERSON is a vote for Anderson” – but its practical effect is inescapable. Which means third parties never get a chance to get a chance; if you want to participate meaningfully in politics at all you have to go with one of the two “big tent” parties. In the other thread I argue (at great length) that this is a bad thing; for purposes of this one let’s just assume that, please, and look for alternatives. Several have been proposed:
- Instant-runoff voting: You, the voter, rank-order the candidates by order of preference. If your first-choice vote is for Buchanan and he does not get a majority of first-choice votes, your second-choice vote for Bush counts in his column. Whoever gets elected has a real majority mandate, i.e., is demonstrably the choice of a majority of the voters.
Criticism of IRV provided in the other thread by ultrafilter.
2. Approval voting: Without rank-ordering, you simply vote for every candidate acceptable to you. You can vote for Bush and Gore and, what the heck, Harry Browne (Libertarian) too. All your votes count the same and the candidates you don’t like don’t get any of your votes.
3. Range voting: You assign each candidate a score within a specified range, say, 0 to 99 or 1 to 5. Think of measuring a certain amount of sand in a graduated cylinder and pouring it into a cub labeled “Bush,” and at the end every voter’s contribution of Bush-sand gets poured into one big pile and whoever has the biggest pile wins (stop that snickering). Approval voting can be considered a form of range voting with only two levels, 1 (approved) and 2 (dissaproved).
Case for range voting as against IRV provided by ultrafilter.
Which is better? Which is more likely to favor emergence of a multiparty political system? And which is better by any other standard you might propose? (See Criteria in evaluating single-member voting systems.)