(Extra: Click link for corrections of errors in the Vermont "easy as 1-2-3" pro-IRV report.)
Unfortunately, a large number of false statements have been made and continue to be made in newspapers, magazines, and on the internet, about Instant Runoff Voting (IRV). And unfortunately, the CVD (Center for Voting and Democracy, a pro-IRV group later calling themselves "FairVote") often says false things.
For example, the CVD, discussing mathematical imperfections in IRV in a page "last updated on Sun Mar 05 2006," misleadingly claims:
Choice voting has been used in public elections for over 100 years in the US and around the world, and we have not uncovered even a single example where any of the theoretical defects have occurred.Ludicrous. Actually, when I examined the five Debian elections 2001-2005 I immediately found that two of them had such problems. In our list of national presidential elections, there are several clear presidential-level examples (Peru 2006, Chile 1970, France 2007) where IRV gave the "wrong winner" plus several more unclear examples where that may have or would have happened (France 2002, Slovakia 2004, Cyprus 1988, Mexico 2006, Iran 2005), plus when we examine the 150 federal IRV elections in Australia 2007 we find at least 9 and probably more like 20 pathologies. This all is far more than "0.1%." Plus if we were to extend the list to also cover, e.g, Senate races, then there would be many more examples, such as the New York State 1970 Senate race. And you can check the 2009 Burlington VT mayor election for a large number of IRV pathologies all in one election – despite the fact fairvote called this election a "great success" for IRV and had pushed for Burlington to adopt IRV (after this election, it repealed it). Or the Ireland 1990 presidential IRV election, again often cited by Fairvote as a "great success" example, but actually demonstrating some serious pathologies. (Fairvote apparently always ignores the pathologies in the very elections they highlight as "great successes" then says things like these pathologies have never ever occurred. All lies.) And the CVD forgot to say that usually, the votes in IRV elections have been kept secret which has prevented anybody from noticing a problem. Continuing on to the next false CVD statement in this same document:
This includes tens of thousands of elections with tens of millions of voters. If the theoretical problems with choice voting occurred even as frequently as 0.1% of the time, there would be many such examples, but there are none.
"Single Transferable Vote Resists Strategic Voting," Social Choice and Welfare 8 (1991) 341-354.A complete lie. Many simple and realistic counterexamples are provided on CRV pages e.g. this and this one. In fact, the examples of hard-to-manipulate elections used in the article they cited are (as its authors would readily admit) what are "unrealistic and artificial." IRV ("choice voting," as the CVD here calls it) often is easy to manipulate in realistic scenarios, i.e. with a bounded number (such as 3 to 7) of candidates; only in their paper's hard examples with half as many candidates as voters is manipulation proved computationally difficult. Is that "realistic"? I don't think so! (Next time you find a realistic election with 5000 candidates and 10000 voters, let us know.) Indeed, this entire line of research was refuted by this paper by Conitzer & Sandholm showing that every "reasonable" rank-order voting system is usually easy to manipulate.
This article shows mathematically that choice voting is virtually impossible to manipulate, which explains why no real world example has ever been found. The only examples people raise are highly unrealistic, artificial ones.
Crispin Allard, "Lack of Monotonicity – Revisited," Representation 33 (1995) 49.Another complete falsehood: Allard's work was based on an incorrect calculation. You can find more details of the incorrect calculation in
As Professor Amy writes in Behind the Ballot Box, referring to the Allard paper, "One statistical study founded that if STV elections were to be held through the United Kingdom, a nonmonotonic result would occur less than once a century."
Crispin Allard: "Estimating the Probability of Monotonicity Failure in a UK General Election," Voting matters 5 (January 1996).But if you redo Allard's calculation correctly then you find out that in Allard's probabilistic model of 3-candidate IRV elections, a nonmonotonic one happens once every 95 elections, i.e. for the 659-member UK House of Commons, 7 members would be elected nonmonotonically each time! And that's only counting one kind of nonmonotonicity – count the other and we are up to 5.4% of elections in Allard's model. Furthermore, in different, arguably more realistic probabilistic models than Allard's, a nonmonotonic election happens much more often, namely 5-15% of the time in 3-candidate IRV elections and 100% of the time in N-candidate elections when N is made large.
"The rate of spoiled ballots did not increase in any of the U.S. cities when they switched to IRV." – Fairvote.org web post, June 2008.
False. San Francisco, Fairvote's "biggest success," immediately after switching to IRV experienced an increase in spoiled ballots versus the plurality-voting races held on the same day (same voting booths, some voters) by a factor of seven.
Here are a selection of IRV errors from newspapers:
The League of Women Voters of Minnesota put out a study (2.5MB) on alternative voting systems which unfortunately made IRV look considerably better than it should have. Their quick summary of IRV is highly misleading:
Instant Runoff Voting System (Voters rank candidates; votes for candidate with fewest first-choice votes are redistributed according to their second choices until one candidate achieves a majority)Of these 5 items, numbers 1 (counterexample) and 3 (counterexample election and another and another and another!) are simply false. The League also misleadingly characterizes Condorcet methods by saying "May result in a tie that requires pre-election decision on how to break tie." While I suppose that is technically true, the same thing is true for every election method: and ties seem far more likely to happen in IRV than in Condorcet methods since a crucial tie can happen every IRV round.
- Ensures majority rule
- Allows voters to express preferences among candidates
- Eliminates problems of spoiler candidates knocking off major candidates
- Eliminates need for run-off elections
- Does not meet mathematical requirement for monotonicity
The League report criticizes Plurality, Approval Voting, Borda, and Condorcet for being "vulnerable to manipulation." But they don't criticize IRV for being vulnerable to manipulation. A naive reader would reach the false conclusion that IRV was immune to manipulation! (In fact, Approval is probably superior in this respect to IRV, and in at least some ways, Condorcet is also.)
The League also always stress that Approval Voting, Borda, and Condorcet were good methods only according to "mathematical" considerations. They always stress that IRV's violation of monotonicity was only a "mathematical" problem. They always stress that only mathematicians consider e.g. the Condorcet criterion and the monotonicity criterion important. This is annoying and misleading.
The League also quotes Ramsey County Election Manager Joe Mansky as saying that counting IRV elections is no problem: "with the right computer software, we can count any ballot you want." That's completely false because IRV elections simply cannot be counted in individual precincts. It doesn't matter what software you have or how much work you are willing to do. It simply cannot be done. IRV elections can only be counted statewide – as opposed to range and plurality voting where precincts can count their own totals and send only them to a statewide center. This whole point is totally ignored by the League report and would require a massive change in all or almost all US states' procedures.
The League also screws up in their appendix 3 where they discuss the constitutionality of various voting systems. They claim IRV is constitutional and Approval, Borda, and Condorcet are not because IRV passes both these tests:
Here are 4 sentences by Steven Hill, "senior analyst for the Center for Voting and Democracy (CVD)" and author of the book Fixing Elections: The Failure of America's Winner Take All Politics:
Indeed, the CVD is a font of falsities about IRV:
Instant runoff voting eliminates concerns about "wasted votes" and the "lesser evil" dilemma.Both those statements are false. In our counterexample (or this) we repeat for the umpteenth time, if you honestly vote Nader>Gore>Bush, then your vote is "wasted" and causes both Nader and Gore to lose, whereas a dishonest vote for the lesser evil Gore would have caused Gore to win (which you prefer).
Dan Cooper correctly remarks: Approving of Kerry and Nader will never help create a Bush victory [under "approval voting"], whereas ranking Nader above Kerry could help Bush win under IRV voting. Once IRV voters understand that, strategic voting is guaranteed.
I would like to thank Markus Schulze and Abd ul-Rahman Lomax for bringing some of the above falsities to my notice.
From the 2004 Green Party USA platform:
8. We demand choices in our political system. This can be accomplished by proportional representation voting systems such as
Choice Voting (candidate-based), Mixed Member Voting (combines with district representation), and Party List (party based); and semi-proportional voting systems such as Limited Voting, and Cumulative Voting.
All are used throughout the free world and by U.S. businesses, and community and non-profit groups to increase democratic representation. We call on local governments to lead the way toward more electoral choice and broader representation.
9. We believe in majority rule and reject the present method of election without a majority. Accordingly, we call for the use of Instant Runoff Voting in chief executive races, (mayor, governor, president, etc.) where voters can rank their favorite candidates (1,2,3, etc.) to guarantee that the winner has majority support and that voters are not relegated to choosing between the lesser of two evils.
10. We believe in multi-party democracy for partisan elections as the best way to guarantee majority rule, since more people will have representation at the table where policy is enacted. We assert that introduction of a multi-party democracy is essential because
- The change in the structure of electoral politics will moderate the influence of extremist views and domination by the larger parties, and offer more fair representation to a greater number of citizens; and
- A third party can validate and raise other points of view that need to be heard.
Unfortunately this platform is in error in several respects:
(a) "Choice Voting" (at least as that word often is used by fairvote.org) is a simplified form of Instant Runoff (IRV) voting, which is a single-winner, hence not a proportional representation, system. See this discussion. (Also, the fact the Greens "believe in majority rule" completely contradicts their call for "proportional representation," which they would recognize if they understood these ideas.)
(b) Instant runoff voting does not cause the winner to have "majority support" as we keep saying again and again, and keep referring you to this counterexample election.
(c) Instant runoff voting does not prevent the "lesser of two evils" effect, as we also keep saying again and again, referring you to, e.g, this counterexample, or this one, or this or this.
(d) Sure, it'd be great to have "multi-party democracy" but the Green Party – suicidally stupidly – here is endorsing a system known to lead to self-reinforcing 2-party domination! Death wish? See this list of reasons US third parties should not want IRV.
From the Libertarian Party platform (amendment enacted 5 July 2002):
Electoral systems matter. The predominant use of "winner-take-all" elections in gerrymandered, single-member districts fosters political monopolies and creates a substantial government-imposed barrier to election of non-incumbent political parties and candidates. We propose electoral systems that are more representative of the electorate at the federal, state, and local levels, such as proportional voting systems with multi-member districts for legislative elections and instant runoff voting (IRV) for single winner elections.
The Libertarians here are considerably more accurate in their wording than the Greens, but the bottom line is they still, suicidally stupidly, endorse IRV even though that is known to lead to self-reinforcing 2-party domination. Again, see this list of reasons US third parties should not want IRV, stop having a death wish, and start endorsing a system that will actually lead to third parties being able to stably exist. Try range voting.
There's a little in some of them. Similarly to what the LoWV says, it is true that IRV is usually thought to be comparatively immune to manipulation in practice. But Approval voting was designed with that goal in mind, a fact the LoWV report fails to mention.
The Vancouver Columbian in its 22 March 2003 editorial "In Our View: A Better Ballot?" said:
"WA State Rep. Jim Moeller, a Vancouver Democrat and sponsor of HB 1390 [bill calling for IRV elections], also hopes the method will make campaigns more civil. `You don't want to sling mud and call people names if you have a chance of being the second choice,' Moeller told The Columbian's Don Jenkins last week."
This may make logical sense. We are not sure. If one candidate is leading, it certainly seems in the interests of the remaining ones to attack him or her. There may be a case that IRV (or other voting methods – just which are unclear) reduces "negative campaigning" (whatever that is), but we are unaware of any clear and irrefutable argument for it (or even a clear definition of it). It seems largely an unsubstantiated hope rather than a reality – but it might have some truth. One thing we can say for sure is that IRV favors extremists, which seems on its face to contradict the notion compromise and centrism is a desirable strategy for candidates in IRV races.
Also, IRV is "immune to vote splitting" in the following (fairly weak) sense. Suppose the electorate (and the candidates) consists of various disjoint "camps," where every voter in camp j ranks all type-j candidates ahead of all non-j candidates. Then,
Theorem: regardless of how the camps "split their votes" among their-type candidates, if there exists a camp containing over 50% of the voters, then some candidate from that camp is guaranteed to win the IRV election.
Proof sketch: at some point a top-camp candidate will have >50% of the top-rank votes (after transfers) and hence can never be eliminated. Q.E.D.
But if no camp contains >50% of the voters, then it is not the case that a candidate from the most numerous camp must win an IRV election. (E.g, camp A could have 35% and camps B and C 32 and 33% of the voters, but a type-C candidate could still win if many of the B-voters transfer their allegiance to him after all B-candidates and appropriate other candidates are eliminated, and whether this happens does depend on how the B-voters [and A- and C- voters] split their votes among the As and Cs.)
The property of the theorem is not a terribly strong property and it is not unique to IRV. (Still, it is a good IRV benefit. Most ``weighted positional'' systems like Borda disobey this property, so in this sense IRV is superior to them.) For example, the property of the theorem is also obeyed by every voting system obeying the "winner in Smith set" property, such as Schulze beatpath voting, Heitzig River voting, Tideman ranked pairs, many Condorcet methods, Copeland, Nanson, and Woodall-DAC. So IRV in no way specially enjoys some kind of anti-splitting property.
For another example, approval voting (AV) also obeys this property provided camp members approve all candidates from their camp and disapprove of all others, and indeed AV then obeys the much stronger property that a candidate from the most-numerous camp then must win.
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