I've never been very happy with the way we vote here, using plurality or "first-past-the-post" voting, but most of the proposals I've seen for reform leave me cold.
Apparently "benham" thought I was referring to IRV ("instant runoff voting," usually referred to in older literature as "alternative vote") and asked what about that system leaves me cold. Actually, in a system such as Australia's, where there are really only two parties that count (actually three, but the Liberal and National parties are so closely aligned that they can be considered one party), I think it works rather well. If you like a minor party, you can give it your first preference, then save your second preference for a major-party candidate and actually make a difference to the voting result. I'm not so sure it works as well if you have a number of different parties which agree on some issues and disagree on others, but I've never seen a place other than Australia that uses it (it's been adopted in some cities in the USA, but so recently that the results of the experiment haven't been seen).
Actually, the systems that "leave me cold" meant approval voting, the Borda Count, and Condorcet voting, and there will probably be further posts of mine addressing these specifically.
2 comments:
IRV does a good job of getting the right answer in what CRV has called "two and a half candidate elections", in which there are only two serious candidates, plus one or more minor candidates of little consequence.
It does, however, have major flaws that can become apparent when the number of genuine candidates expands. One of these is nonmonotonicity, as demonstrated by the following example (first posted on a Neighbours fan site):
Suppose Erinsborough hold an election for the Citizen Of The Year award. There are three candidates - Lou, Susan and Harold. The votes are as follows:
26,000 prefer Lou to Susan to Harold
25,000 prefer Harold to Lou to Susan
49,000 prefer Susan to Harold to Lou
The next year, they hold the election again. Same candidates, mostly the same voters' preferences. Except that 2000 people have been swayed by an editorial by Riley Parker in the local paper, and therefore move Susan from first to last in their preference list. So the new election's votes are as follows:
26,000 prefer Lou to Susan to Harold
27,000 prefer Harold to Lou to Susan
47,000 prefer Susan to Harold to Lou
Who wins the first election? Who wins the second?
You say "IRV does a good job of getting the right answer in what CRV has called 'two and a half candidate elections', in which there are only two serious candidates, plus one or more minor candidates of little consequence." This is pretty much what I meant by my comments on Australia.
In general, what you've said is pretty much in agreement with what I said.
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