In a recent
diary entry we started discussing Instant Runoff Voting and other voting methods. One of the responses talked about Arrow's Theorem and how there is no perfect voting method. I commented but wanted to Diary it too because of a poll I thought of.
Arrow's Theorem is given too much importance in judging political vote-counting procedures because it places emphasis on the Independence of Irrelevant Alternatives Criteria. What too many people neglect is that violating the IIAC is only a flaw if another criteria is met, and that criteria is if every single participating voter feels equally represented by the voting choices.
In other words, if some people are rabidly in favor of someone, but other people are not excited about any candidate and feel like they are compromising when they vote, then introducing a new candidate and violating the IIAC can be a good thing.
Since all political elections are filled with compromise candidates, then IIAC, and thus Arrow's Theorem, shouldn't be applied to vote-counting mechanisms as a foolproof way to judge their fairness.
Despite all that, it's important to know that Condorcet's method is actually perfect and doesn't even violate IIAC (or the rest of Arrow's Theorem) if there are no tiebreaker processes needed. In practice, it's actually pretty rare that a tiebreaker would be needed in a Condorcet political election.
Basically, Condorcet is completely superior to the other methods.
However, there is some reason to oppose Condorcet on philosophical grounds alone, and that's illustrated by this question:
Say you have a vote with three candidates. Say that 51% of the population rabidly supports candidate A, while a very significant percentage (> 40%) rabidly oppose him. Or maybe even 49% hate him.
Now say that 80% of the nation would also be okay with candidate B, even though many people don't have him as first choice. He'd be more a consensus choice.
Who should win? There are many that would say that A should win, because of their views on competition and majority rule. Condorcet would find candidate B as the winner, as B would have the broadest support, representing the largest portion of the population.
I'll make that my poll question - who should win, A or B?