Last year, in a series of posts, including this one, I discussed proportional representation. There are other alternative voting systems that, like proportional representation, have mainly been used outside the U.S.
Now, my native city of Minneapolis is adopting one of those systems, Instant Runoff Voting (IRV), for its municipal elections. Actually it's normal IRV, not FIRV as indicated in the headline on this post; I'm merely fondly remembering (from a safe distance) the winters of my childhood.
That city's former procedure had involved a non-partisan primary. There was only one primary, rather than a separate one for each party. And no candidate was identified by party on the ballot. The top two vote-getters in the primary would face off in the general election, again without being identified by party. Barring a tie (highly unlikely, although the state came close to such an outcome in its U.S. Senate election last year), the winning candidate in the general election had a majority of the votes.
Rather than casting one vote for their favored candidate, under IRV a voter will rank all of the candidates in order of preference. If one candidate gets a majority of first-place votes, he or she is elected. Otherwise, the last-place candidate is eliminated, and the second-place votes of that candidate are distributed among the remaining candidates. That procedure is repeated until one candidate has a majority. (The city also holds elections, such as that for its park board, which involve filling multiple positions. The math gets more complicated in those cases. For a further explanation, see this court opinion which rejected a challenge to the city's adoption of IRV.)
One clear benefit for Minneapolis is that it will avoid the expense of holding separate primary and runoff elections. The electorate will vote only once, and the "runoff" will merely be a matter of doing the math.
Other practical considerations involve potential difficulties. People like me, who eat, sleep and breathe politics, will have known about IRV for many years, and will be ready to go, when the first IRV election comes up. But I'm absolutely certain that, despite all efforts at voter education by the state, the parties, and the candidates, there will be many voters who go to the polls, and still need to have it explained to them, why they can't just put an "X" next to their favorite candidate's name, as they've been doing all their lives.
Also, there will be some issues with counting the votes. According to some reports, polling places will not, yet at least, be equipped with voting machines designed to handle the IRV process.
But aside from all that, how might it change voting behavior? My guess is that, in places such as Minneapolis where it's replacing a non-partisan primary, not much. IRV is just a more efficient way of implementing the same runoff that that system has always had.
If, however, IRV were implemented at a general election, following partisan primaries, I suspect that it would result in increased support of third-party candidacies. In recent years, the Independence Party, the third party that grew out of Jesse Ventura's successful gubernatorial candidacy in 1998, has been getting a sizable share of the votes in Minnesota's statewide elections. None of its candidates, other than Ventura, have come anywhere near victory, but it continues to garner much higher percentages than, for example, the Libertarians or the Greens.
Under the traditional system, an Independence voter will have no say about the preference between the Republican and Democratic candidates, if, as is usually the case, the Independence candidate finished third. But, under IRV, a voter can vote Independence with a Republican second choice, or Independence with a Democratic second choice. That would not be a wasted vote. And if there were enough such voters, then perhaps third-party candidates might win every once in a while, and not only once in a lifetime when the stars are aligned just right, as they were for Ventura in 1998.
Whether that would be a good or a bad thing depends on whether you want 1) the stability represented by continuation of the existing two-party system, or 2) the shake-up that would come with at least occasional third-party victories. I lean toward #1, but I think it's somewhat of a close call.