Instant Runoff Voting
One way to avoid splitting groups of voters, called Instant Runoff Voting or IRV, has been used in Australia's national elections since 1919. IRV uses the same preference-rank ballots as Condorcet's rule. But the way it counts ballots is totally different.
Here is an analogy: Each candidate puts out a box. A voter puts his ballot in his favorite candidate's box. The ballots are counted. If the box gets a majority of the ballots, it wins. If not, the voter moves his ballot to another candidate's box. Or, he waits, hoping others will move their ballots to his favorite box. To break that deadlock, we have a rule: If a round of counting ballots finds no winner, the box with the fewest votes is eliminated. Its ballots go to each voter's next (2nd) choice -- probably a candidate with similar views and more popularity.
These transfers make voters condense into large groups supporting strong candidates. Ballots are counted again to see if any candidate gets half of the current top ranks.
In practice, each voter ranks the candidates as 1st choice, 2nd choice, 3rd etc. Then election officials move ballots between boxes or a computer tallies them.
Ranking a second choice can't hurt your first choice -- the second does not count unless the first choice has lost.
Here again is our example with 7 voters choosing 1 winner from 4 candidates -- which are labeled A, B, C and D. Click a ballot (in Table I) to highlight the candidate totals (in Table II) which that ballot helps. Or click on a candidate's total (in Table II) to check which ballots (in Table I) add to it.
In step 1 below, no one gets a majority. Candidates A and C each have only 1 ballot so they are tied for last. C ranks higher on most ballots so in step 1 we eliminate A and move Uri's ballot to his next choice, B.
The ballot transfers organized these voters into large groups supporting strong options. Who wins by plurality rule? Hint: look at step 1.
Four of the 7 ballots rank IRV winner B over plurality winner D. But a different 4 of the 7 voters ranked Condorcet winner C over B. Condorcet rules find a majority which is insurmountable, the "top majority". Thus Condorcet's pairwise rule is sometimes better than the IRV elimination rule for electing a single central winner, but usually both rules pick the same winner.
Merits of IRV
Moderate candidates get a better chance to win election. We too often see a far-right candidate lead a couple thousand zealous supporters to vote in a primary election, and so win the Republican nomination in a district that always elects that party's nominee. A mirror image may occur in districts controlled by the Democrats. IRV can reduce the chances of that by combining the primary with the general election, greatly increasing the number of Republican voters and independents who help select their party's representative.
Here's a very short “elevator pitch” for IRV.
The results of Instant Runoff Voting are:
Here's another quick one:
Australians call IRV "Alternative Vote" or "Majority Preferential Voting" and use it to elect their lower house of parliament and the mayors of all their major cities. The Irish use it to elect their president and mayors. Academics often call it Single Transferable Vote or STV, a name that describes the tally process: each voter casts a single vote which can transfer during steps of the runoff.
IRV is used at many American universities and colleges including Brandeis, Brown, Cal Tech, Carleton, Clark, Clemson, Dartmouth, Duke, Harvard, Johns Hopkins, Macalester, MIT, Portland State, Princeton, Reed, Rice, Stanford, Tufts, UC Berkeley, UC Chico, UC Davis, UCLA,UC San Diego, University of Illinois (Champaign-Urbana), University of Maryland, University of Minnesota, University of Oklahoma, University of Virginia, University of Washington, University of Wisconsin, Vassar, William and Mary, Wake Forest, and Whitman.
Comparing single-winner rulesPlurality rule rewards a candidate only for winning first-choice votes; that means winning intense supporters. IRV rewards a candidate who wins many firsts (to avoid early elimination) and a majority of high preferences over a rival who also has intense support; this requires some intense support but also a broad appeal. Condorcet's rule uses all preferences to find the one candidate who can win majorities over each of the rivals, it ignores very intense support to require a broader appeal.
(Approval voting completely ignores intensity of support: a voter's third-choice approval counts as much as his first choice. This may lead to the broadest appeal. But it introduces inaccuracy and motivates tactical voting to prevent a third choice from hurting the first choice.)
The viable candidates in a Condorcet election will be close to the political center, and to each other. Under plurality rule that often leads to:
But under Condrcet:
Some rules reward a candidate for ads attacking minorities as a divisive "wedge issue" to breakup the opposing coalition. Under plurality rule and majority rules such as runoff and instant runoff, a conservative candidate knows she has no chance of winning traditionally liberal voters, gays for example. She may seek favor among far-right voters by vilifying gays. In a multi-candidate contest under plurality rule she may even denigrate centrists. Condrcet and IRV make that tactic a loser because central voters are the key to winning the final 1 against 1 runoff.
Under Condorcet's rule each conservative may be ranked by progressives. Many will punish a gay basher with low ranks relative to other conservatives so her gains among far-right voters may be offset by losses among progressives. This rule is not likely to reward the politics of hate. So Condorcet's rule, used by itself, would threaten many politicians who have built successful careers far to the left or right of center. They could continue those careers in the kind of diverse council explained in the next chapter.
IRV is the best rule for electing a chief executive with the power to arbitrarily veto a council's legislation. To prevent deadlocks between the legislature and the executive, she needs strong ties to a large bloc of reps and IRV makes this very likely: She is almost certain to come from one of the 2 largest parties and to have "coattails", popularity that helps elect reps from her party.
IRV will cause little political turmoil. Yet it will ensure that every elected leader wins a majority -- unlike the plurality winners who lack that respectable mandate. Thus IRV can strengthen a democracy and is a good step in political evolution. It introduces voters, politicians and election administrators to ranked ballots. That will make it easier to introduce the multi-winner form of IRV for reps balanced right and left of center. That rule, together with Condorcet chairpersons, can create "mixed member" councils that are inclusive, well-centered and decisive... as we shall see in the next two chapters.
In the Korean example, ballots for the weaker liberal could have transferred to elect the stronger one under Instant Runoff Voting.
The tabletop tallies page showed an effective way to get students involved in their own IRV tally. A later page in this chapter will contrast the tendencies of Condorcet, IRV and other rules using data from simulations. The chapter on electing councils tells why many political scientists think the multi winner version of IRV, called Single Transferable Vote or STV, is the best rule for electing a council. And the chapter on setting policies will tell why IRV is a good rule to use when there is no Condorcet winner.
The Tool page has programs to tally IRV.
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