a critique of Instant Runoff Voting

Election 2000 was traumatic enough that some people prefer to look for flaws in the system itself rather than finger blame on the players. As an alternative, many have discussed Instant Runoff Voting (IRV) as one way to prevent a third party from playing a spoiler role in a close election.

However, there are some dangers inherent in assuming that IRV is a panacea. The effectiveness of any alternative system needs to be weighed against the current plurality method not just in the third-partry spoiler scenario, but in all scenarios.

IRV can prevent the spoiler effect, in which a minor party splits the vote with a major party and tilts the election toward the other major party, hurting its own cause. IRV therefore seems to allow supporters of minor parties to cast protest votes without "wasting" their votes. This advantage is illusory, however, because it applies only as long as those minor parties are sure to lose. As soon as one of those minor parties threatens to become a major party and actually win, its supporters vote for them at the risk of hurting their own cause, just as in the current plurality system. Under IRV, votes for minor parties are therefore symbolic at best, or dangerous at worst. An example will illustrate why.

Suppose my true preference is for the Libertarian first and the Republican second. Suppose further that the Libertarians are the strongest "minor" party. At some round of the IRV counting process, all the candidates will be eliminated except the Republican, the Democrat, and the Libertarian. If the Libertarian then has the fewest first-choice votes, he or she will be eliminated and my vote will transfer to the Republican, just as I wanted. But what if the Republican is eliminated before the Libertarian? Unless all the Republican votes transfer to the Libertarian, which is extremely unlikely, the Democrat might then beat the Libertarian. If so, I will have helped the Democrat win by not strategically ranking the Republican first. But that's the same situation I'm in now if I vote my true preference for the Libertarian!

What happened is the above example is that IRV essentially ignored ony of my key preferences. By voting (Libertarian, Republican, ..., Democrat), I increase the chances that the Republican will be eliminated before the Libertarian. If that then happens, my preference for the Republican over the Democrat is essentially discarded or ignored. This is the fundamental problem with IRV, and the problem gets worse as the number of candidates increases. The outcome of the election can depend in a very quirky way on the order in which candidates are eliminated for having the fewest top-choice votes. The only way a voter can be assured of not wasting his or her vote is to rank one of the two major parties as their first choice, which is precisely what happens now under plurality voting.

The example is hardly contrived. The "lesser of two evils" problem is almost guaranteed to rear its ugly head again under IRV. Until a minor party is strong enough to win, a first-choice vote for them is essentially only symbolic. After a minor party is strong enough to win, on the other hand, a vote for them could have the same spoiler effect that it could have under the current plurality system. Hence, if IRV is ever actually adopted, we will likely remain stuck in the old two-party system, just as Australia still is, despite the fact that it has used IRV since around 1920. On the other hand, if minor parties do somehow manage to become competitive under IRV, they could wreak havoc with our entire system of government. As in our current system, the stronger a minor party becomes, the more it could hurt its own cause.

There's a lot more to the argument, be sure to read the whole link if you are interested. They also have a detailed evaluation of multiple voting methods including (but not limited to) IRV here.

I'm aware that Howard Dean has appeared to endorse IRV (though he certainly hasn't advertised it.)My personal feeling is that the Founders chose plurality for a reason - because it is, by virtue of its simplicity, the most agreed-upon method of concensus throughout human civilization's long history. My preferred method for electoral reform is to encourage (but not mandate) proportional allocation of electoral votes by state rather than winner-take-all. And to repeal the 17th Amendment. But these are topics for another time.. and fodder for your Googling.