[EM] IRV3/AV3
The third rank in IRV3/AV3 is essentially only useful for turkey-raising. For instance, imagine the 2000 election with two Nader clones, Bush/Gore/Nader1/Nader2. Bush voters could vote BushNader2Nader1, and possibly eliminate Gore from the IRV3 round. (Or with honest voting, Gore could be center-squeezed; but that's a separate possibility). Allowing equal rankings and/or having only one runoff round (IRV3/AV2) would help with other problems, but they would if anything make the turkey-raising problem worse. Jameson Election-Methods mailing list - see http://electorama.com/em for list info
[EM] irv3/av3
From: Jameson Quinn jameson.qu...@gmail.com To: EM election-methods@lists.electorama.com Date: Fri, 2 Dec 2011 10:17:52 -0600 Subject: [EM] IRV3/AV3 The third rank in IRV3/AV3 is essentially only useful for turkey-raising. For instance, imagine the 2000 election with two Nader clones, Bush/Gore/Nader1/Nader2. Bush voters could vote BushNader2Nader1, and possibly eliminate Gore from the IRV3 round. (Or with honest voting, Gore could be center-squeezed; but that's a separate possibility). Allowing equal rankings and/or having only one runoff round (IRV3/AV2) would help with other problems, but they would if anything make the turkey-raising problem worse. Jameson dlw: only useful is strong language. ... Let's consider that... Say R-voters are 40%, D-voters are 45% and ND1 and ND2 split the rest... R-voters all vote stragetically B-ND2-ND1 and B-ND1-ND2(50-50) (though one voter refuses to vote strategically) D-voters all vote D. (why would they be worried about their first-rank being disqualfied?) ND1-supporters vote ND1-ND2-D ND2-supporters vote ND2-ND1-D. then D gets 55% of teh vote R gets 40%, ND1 and ND2 both get 40+15% - one vote. So D, ND1 and ND2 go to the 2nd round, where D gets 45, ND1 gets 27.5- one vote and ND2 gets 27.5 - one vote and it's a cointoss. Then the votes get transferred to the other Nader clone and (s)he would win, but only because of the dumb voting strategy of the Republicans. But can the Rs really engineer such a massive strategic voting and would they want to if it might elect a ND clone? The bigger point is that the Dem party machine is very strong. They'd have little need to encourage their supporters to vote for 3rd party candidates as their 2nd/3rd choices and so the Rs wd need to do a lot of strategic voting to make a diff, and could very well end up shooting themselves in the foot. As for center-squeezing, that's not really a problem in the US as a whole... Third parties are too small and scattered. dlw Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] IRV3/AV3
I believe there have to be only 3 candidates and it has to be a close 3-way election for the 20% to be valid. As long as the odds are low enuf, it doesn't matter that much. It just says that in some cases, some folks will have sour grapes. As Jameson says, it depends how you simulate the voters. But there are ways in which I think IRV encourages spoiler scenarios. Consider a city that has a slight Democratic bias. That is, Democrats win by 8-10% most of the time. Step 1) A Progressive party starts up that thinks the Democrats have gotten complacent and are not ambitious enough. This resonates with people but they're scared to vote for third parties. Step 2) IRV supporters tell everyone it's safe to rank your favorite first. Some people rank the Progressives first, and nothing bad happens! People gain confidence in IRV and ranking your favorite first. More people start ranking the Progressive first. Step 3) Eventually the Progressive party overtakes one of the top two parties to make it into the final round. The party overtaken is almost certainly the Democrats (because the Progressive party wasn't taking any votes from the Republicans). So who did the Democrats put for their second choice? If even a small fraction of the Democrats put the Republican second, then the Republican will win, and we have had a successful spoiler scenario. (Yes the Progressive was the spoiler even though they made it to the final round.) Voting for the Progressive caused the Republican to win. Progressives should've put the Democrat first. Step 4) Progressives and Democrats get very angry at each other and everyone is angry at the Republicans. A majority is angry at IRV. Yes, it's sour grapes, but it's not hard to see that it's a really bad outcome. A city that starts 45% Republican and 55% Democrat and then the only change is that some of the Democrats put the Progressive first and the Democrat second should not cause the Republican to win. (Even if a few Democrats put the Republican second.) This was described from the perspective of the left, but it could have been done just as easily in terms of Republicans and a Libertarian or Tea party. All that's required is that the growing third party be a little more extreme than the two major parties (or, as Jameson put it, that the three parties basically fall on a one-dimensional spectrum). Then these steps become natural, even probable. The worst part is that IRV, and IRV supporters by telling people that it's safe to rank your favorite first, encourage the progression down this path-to-spoilers. ~ Andy Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] IRV3/AV3
On Tue, Nov 1, 2011 at 11:01 AM, Jameson Quinn jameson.qu...@gmail.comwrote: 2011/11/1 David L Wetzell wetze...@gmail.com I believe there have to be only 3 candidates and it has to be a close 3-way election for the 20% to be valid. And the candidates must not be organized along a one-dimensional ideological spectrum. That restriction does not hold for many partisan elections, thus the percentage can be significantly higher than 20% for close elections. Can you point to the actual article for me? I've heard o.w. wrt the one-dim spectrum in terms of the top candidates, as opposed to all of the candidates. As long as the odds are low enuf, it doesn't matter that much. It just says that in some cases, some folks will have sour grapes. And over time and place, such possible biases will get evened out... Also not true. There is an clear overall bias against centrists. If you want, I can pull up the citations in my zotero... I'd say it fits with how IRV tends to keep a two-party dominated system in place. This bias though is not as bad when one considers that the big two parties can be more dynamic, moving towards the center in response to the possibility of a centrist party spoiling an election. Same thing for you Andy J, in real life, there's more policy-variables involved. The potential for Party mergers can take a bite out of the Prog-Dem dilemma. Even if the Progs won in 2008 with IRV, by the next election the voting habits would have shifted to take care of the problem. Models are like swimsuits, what they reveal is interesting but what they conceal is often vital... dlw JQ Nonmonotonicity is no good reason to bring back the use of FPTP. Agreed. It was used for pragmatic reasons by those who were upset by how IRV was improving the democracy of Burlington, VT. For at least many voters, the non-Condorcet result was their honest reason for voting for repeal. I don't think it helps to accuse them of mere partisanship. JQ Election-Methods mailing list - see http://electorama.com/em for list info
