[EM] Explaining PR
Catching up from a couple weeks ago, I just wanted to add my short- short version of explaining Proportional Representation that usually gets a good response from people: A 20% group should get 20% of the seats. It's pretty easy for people to be agreeable to that. I think in general it might be easier for people to be agreeable to goals of election reform, and relatively few actually care to analyze the mechanics of how it works. If they are interested in the mechanics, they usually just want to understand it enough to feel they wouldn't be cheated by a mysterious system. Explaining it to the point of, oh yeah, that sounds reasonable is often enough. Depending on the audience, it might even be better to say that a 10% group should get 10% of the seats. Many US Green Party people would love that. Another 'goal' statement I like to use: I want to vote for candidates, not parties. I think a fair number of people have heard vague ideas about how in some places you vote for a party and the party fills in seats with people depending on how many they get allocated. I don't trust party machines even when it's my party, so I want to vote directly for candidates. STV allows this, and I like that (never mind its warts, we'll figure out better ways that also allow candidate voting). Anyway, those are my pithy two bits for the PR debate for now. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR
On Sep 20, 2009, at 7:49 AM, Brian Olson wrote: Catching up from a couple weeks ago, I just wanted to add my short- short version of explaining Proportional Representation that usually gets a good response from people: A 20% group should get 20% of the seats. Kathleen Barber has a nice line in her book A Right to Representation: Proportional representation is a simple principle, derived from democratic theory, that in a representative body the share of seats won should correspond to the share of votes won. The electoral system is thus the link between the preferences of the voters and the making of policy. As Ernest Naville wrote in 1865, In a democratic government the right of decision belongs to the majority, but the right of representation belongs to all. Brian's line gets at the what of PR; Barber and Naville take a stab at why. Raph, I think, was also trying to get at how, specifically for STV. They're all useful questions to ask answer. Tideman does a nice job, I think, in his recent book and a couple of earlier papers, where, in a somewhat longer form, he looks at the evolution of STV, beginning with the easy-to-understand method of Thomas Hill, and proceeding through several refinements to Meek and Tideman's own CPO-STV. One thing I like about this line of explanation is that the starting point is easy to grasp, but it's also easy to grasp its real shortcomings, which makes the next refinement in turn easy to understand as a means of addressing one or more of the shortcomings. Unfortunately, I don't think there's a version freely accessible online (though I haven't searched Google Books recently). Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR-STV
From: Raph Frank raph...@gmail.com Looking at the 3 choices as parts of one whole vote does not change the *truth* is that voters' votes are treated unequally. ?Considered as parts of a vote, some voters have only 1/3rd of their vote considered, while others have 2/3rds or all of their entire vote considered at all, or in a timely fashion. Your vote allows you to increase the total for any any candidate by 1 vote (or group of candidates by 1 vote in total). This statement is misleading at best. To give voters a true picture you need to say: Your vote allows you to increase the total for one or two candidates per round up to at most one vote in sum per round. However in some rounds some voters will have a full one vote and other voters will have less than one or zero votes. Tell the people the full truth about IRV. The rankings are just instructions to the counters on where you want that vote assigned during the counting procedure. Let's be honest and add the phrase that just because you give instructions for how you want that vote assigned does not mean that any vote is assigned to any candidate (even your 1st choice) in a way that will help that candidate's chances of winning. True only in round #1, so entirely misleading unless the statement is qualified. Ok, is the the updated expression above acceptable? Yes. Acceptable to those who would mislead the public on what IRV does. 1. ?their 2nd choice candidate gets ?a vote that could help their 2nd choice candidate win whenever their 1st candidate loses, and that He does, unless the 2nd choice is eliminated before the first choice. Yes, so to give an honest picture, state that. 2. majority favorite candidates win, and that True, this is an issue. The equivalent is that only candidates who meet the Droop quota would be given a seat in PR-STV. Huh? That is equivalent to the lie being told to the public that IRV finds majority winners? I don't see it. I think that would be reasonable, but some people might not like that their district ends up with 1 fewer representatives. Well IRV can not elect candidates to all the seats if it follows its own rules for quotas. 3. a vote for a candidate always helps, rather than hurts that candidate's chances of winning, etc. I think the non-monotonicity is not as big an issue with PR-STV when the number of seats gets larger. The more seats being filled, the more accurate your polling. Well the 75 voters in Aspen who caused their favorite candidate to lose by ranking him first (whereas he would have won if they hadn't), may disagree with you, as per this oped in the Aspen Times this week: Aspen City's Waning Credibility http://votingnews.blogspot.com/2009/08/aspen-times-citys-waning-credibility.html Also, giving a candidate a higher ranking certainly helps on average. Well that is where you and I disagree philosophically -- I think voters have a right to know that their vote helps, rather than hurts a candidate's chances of winning. Lots of canvassers in Ireland, when they are canvassing, will ask for a first choice and if you say you are voting for another party, they will ask for the 2nd chocie. So what? I fully understand the mechanics of the wholly unfair inequitable IRV/STV counting methods whereby the supporters of the least popular (first eliminated) candidates get to have their votes reallocated to decide which other candidates are eliminated first and whereby the voters of the early round winners in STV get to cast part of their votes for their 2nd and/or 3rd choice candidates. IRV does seem an improvement over plurality. Plurality also can result in a winner who doesn't have majority support. IRV is a big big step down from plurality voting due to its fundamental unfairness of the way it treats ballots and due to its removing voting rights, eviscerating election transparency and verifiability, huge cost increases, etc. etc. Read my long, but easy to read report on IRV with an open mind: http://electionmathematics.org/ucvAnalysis/US/RCV-IRV/InstantRunoffVotingFlaws.pdf and add if any uneliminated candidates remain on your ballot at that point to give a more accurate picture of what happens to your choice votes. Sounds reasonable. Right, there is up to 1 Droop quota of voters who don't get represented. ?However, this is much better than potentially 49% of the voters not being represented in a single seat district. In a single seat election, IRV can do much worse than that and elect a candidate whom the majority of voters *opposes*. So can plurality. (and again, I don't think IRV is a very good method for single seat elections). STV has all the same flaws as IRV, plus some. However, it is an improvement (at least slightly) over plurality. IRV/STV is a HUGE threat to the fairness and integrity of elections as compared to plurality. You do not seem to understand that in IRV you can **never* give your first
Re: [EM] Explaining PR-STV
On Sun, Aug 30, 2009 at 4:15 PM, Kathy Doppkathy.d...@gmail.com wrote: I think that would be reasonable, but some people might not like that their district ends up with 1 fewer representatives. Well IRV can not elect candidates to all the seats if it follows its own rules for quotas. I think people would prefer all seats filled in their district than to have some majority failure seats. Also, why do you have a problem with IRV not obtaining a majority, but no problem with using plurality which also doesn't always obtain a majority? I think the non-monotonicity is not as big an issue with PR-STV when the number of seats gets larger. The more seats being filled, the more accurate your polling. Well the 75 voters in Aspen who caused their favorite candidate to lose by ranking him first (whereas he would have won if they hadn't), may disagree with you, as per this oped in the Aspen Times this week: Right, IRV is not a good single seat method. However, the impact of the problems are lessened with PR-STV. Well that is where you and I disagree philosophically -- I think voters have a right to know that their vote helps, rather than hurts a candidate's chances of winning. But in PR-STV, it is likely to help. The issue is greater in IRV (as polls are more accurate, so it is possible to abuse the non-monotonicity, more easily). Lots of canvassers in Ireland, when they are canvassing, will ask for a first choice and if you say you are voting for another party, they will ask for the 2nd chocie. So what? It shows that in actual elections candidates want voters to give them second choices. In fact, I have never heard a candidate say that it would be better for a voter not to risk it. In real elections, ranking a candidate higher is likely to help the candidate. After the fact analysis of a specific election might show that it wasn't the case. It is almost impossible to take advantage of the non-monotonicity, in practical PR-STV elections. However, when dealing with a single seat, it can be an issue. IRV is a big big step down from plurality voting due to its fundamental unfairness of the way it treats ballots and due to its removing voting rights, eviscerating election transparency and verifiability, huge cost increases, etc. etc. In Ireland, PR-STV counts are done by hand in public view, and they are considered very transparent. STV has all the same flaws as IRV, plus some. But they have less negative effects. PLUS IRV adds nonmonotonicity, removes voting rights, adds costs and complexities, and reduces fairness, etc. Well, in the 2 candidate case (plus minor candidates), then one of the top-2 wins as currently. Each voter still gets 1 (movable) vote. However, this method means that if you want to support a party, you have no choice but to vote for the party's candidates. Huh!? Does that statement make any sense? Maybe I like a party but hate their current candidate. With PR-STV, I can just vote for a different candidate from the same party. I have yet to see any method proposed that is worse than IRV/STV short of dictatorship. IRV may be little better (and possibly worse) than plurality, but it is not dictatorship. PR-STV with reasonably large districts puts most of the power in the hands of the people. They get to pick which parties win and also which candidates within the parties win. Absolutely false, In fact most of the methods that solve that problem are precinct-summable, as are both Condorcet and range and approval voting and Bucklin methods - and do not remove voting rights and are FAIR, unlike STV/IRV. Again, I am talking *PR* methods. The condorcet equivalents for PR-STV are all very complex (CPO-STV and Schulze-STV). If not for the complexity, I would much prefer those methods. However, I think that standard-grade PR-STV is still a big improvement over single seat election methods. I am willing to accept that ranking a candidate higher increases the probability of him winning, Then you are accepting a blatant falsehood because IRV/STV elicits nonmonotonicity more as the number of candidates running increases, as has been mathematically proven, and nonmonotonicity, (hurting your candidates' chances of winning by voting for them) frequently occurs in IRV/STV. A non-monotonic method can pass my criterion. It just has to increase the chance of the candidate winning. The probability is worked out when casting the vote (based on generally available information), not when looking at the final result. For example, imagine a (granted crazy) method where each person votes for 1 candidate. However, a higher last digit is a worse result (if the other digits are equal). So, 123,456 loses to 123,451 (as 1 is better than 6 as a last digit) but 123,456 beats 123,000 (as the last digit rule only applies when the other digits are tied). If I vote for some, it will probably increase his last digit (so be bad), but on average it is still
Re: [EM] Explaining PR-STV
On Sun, Aug 30, 2009 at 11:39 AM, Raph Frankraph...@gmail.com wrote: On Sun, Aug 30, 2009 at 4:15 PM, Kathy Doppkathy.d...@gmail.com wrote: I think that would be reasonable, but some people might not like that their district ends up with 1 fewer representatives. Well IRV can not elect candidates to all the seats if it follows its own rules for quotas. I think people would prefer all seats filled in their district than to have some majority failure seats. Yes.We agree. Then you agree that the IRV/STV method should not be used since it virtually always fails the majority criteria quotas that it sets and fails to elect a sufficient number of candidates to fill all the seats? Also, why do you have a problem with IRV not obtaining a majority, but no problem with using plurality which also doesn't always obtain a majority? Often IRV/STV is sold as replacing top-two runoff systems, thus why do you support replacing a majority system with a non-majority IRV/STV system, necessitating that any jurisdiction that adopts RCV or IRV eliminates any of its majority requirements? Well the 75 voters in Aspen who caused their favorite candidate to lose by ranking him first (whereas he would have won if they hadn't), may disagree with you, as per this oped in the Aspen Times this week: Right, IRV is not a good single seat method. The Aspen election used STV and that is how the nonmonotonicity resulted, in a multi-seat city council election. You should do due diligence to investigate the facts, actually read the articles or reports on STV in Aspen and Burlington, etc. so you don't confuse your imagination of what STV/IRV do with the reality of what they do,and be willing to tell people the truth about how IRV/STV really works, namely that it removes their voting right to cast a vote for a candidate that positively effects that candidate's chances to win in both IRV and in STV. However, the impact of the problems are lessened with PR-STV. Again, the majority-favored, most popular city council candidate who lost thanks to STV's nonmonotonicity and all his supporters in Aspen might disagree with you. Well that is where you and I disagree philosophically -- I think voters have a right to know that their vote helps, rather than hurts a candidate's chances of winning. But in PR-STV, it is likely to help. The issue is greater in IRV (as polls are more accurate, so it is possible to abuse the non-monotonicity, more easily). Again, we disagree because I think that voters have a right to know that their vote helps, rather than hurts a candidate's chances of winning, whereas you think voting should be like gambling where voters have a *chance* that their votes *may* help or *may* hurt their candidate's chances of winning. It shows that in actual elections candidates want voters to give them second choices. OK. So what? In real elections, ranking a candidate higher is likely to help the candidate. Or in STV/IRV it may hurt that candidate's chances of winning or not affect it at all. It is almost impossible to take advantage of the non-monotonicity, in practical PR-STV elections. Yes, but it certainly advantages the less popular candidates and it certainly is possible for voters of more widely supported candidates to be penalized by it and for nonmonotonicity to cause a majority-opposed candidate win while a majority-favorite loses in STV/IRV. It is impossible to take advantage of lots of very negative things in life, does that mean we should support every negative thing that some advantage can not be planned of it in advance? I mean I can't take advantage of all the crime that is committed in the town I live in, but it still hurts me. According to your logic I should support all the crime in my neighborhood since I can't take advantage of it? I truly don't have time to continue rebutting what I consider to be wholly irrational and worst imaginable method of counting votes, STV/IRV. -- Kathy Dopp Town of Colonie, NY 12304 phone 518-952-4030 cell 518-505-0220 http://utahcountvotes.org http://electionmathematics.org http://kathydopp.com/serendipity/ Realities Mar Instant Runoff Voting - 18 Flaws and 4 Benefits http://electionmathematics.org/ucvAnalysis/US/RCV-IRV/InstantRunoffVotingFlaws.pdf Voters Have Reason to Worry http://utahcountvotes.org/UT/UtahCountVotes-ThadHall-Response.pdf Checking election outcome accuracy --- Post-election audit sampling http://electionmathematics.org/em-audits/US/PEAuditSamplingMethods.pdf Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR-STV
On Sun, Aug 30, 2009 at 6:55 PM, Kathy Doppkathy.d...@gmail.com wrote: Yes.We agree. Then you agree that the IRV/STV method should not be used since it virtually always fails the majority criteria quotas that it sets and fails to elect a sufficient number of candidates to fill all the seats? And replaced with what? I wouldn't vote for IRV as a single seat method (except perhaps relative to plurality). I agree it isn't a good method for single seat districts. Often IRV/STV is sold as replacing top-two runoff systems, thus why do you support replacing a majority system with a non-majority IRV/STV system, necessitating that any jurisdiction that adopts RCV or IRV eliminates any of its majority requirements? Well different voters vote in the run-off. If a voter doesn't fully rank, then you could argue that they had abstained from the subsequent rounds. Right, IRV is not a good single seat method. The Aspen election used STV and that is how the nonmonotonicity resulted, in a multi-seat city council election. Hmm, I assumed by IRV, they meant the single seat method. You should do due diligence to investigate the facts, actually read the articles or reports on STV in Aspen and Burlington I read the linked page. I assumed that IRV meant the single seat method. Is this not the case? The council is elected from a single multi-seat district? etc. so you don't confuse your imagination of what STV/IRV do with the reality of what they do,and be willing to tell people the truth about how IRV/STV really works, namely that it removes their voting right to cast a vote for a candidate that positively effects that candidate's chances to win in both IRV and in STV. I still stand by my claim that it is advantageous on average for multi-seat. In my experience, the non-monotonicity only can be determined after the fact. However, the impact of the problems are lessened with PR-STV. Again, the majority-favored, most popular city council candidate who lost thanks to STV's nonmonotonicity and all his supporters in Aspen might disagree with you. So, Aspen is single seat IRV then? In real elections, ranking a candidate higher is likely to help the candidate. Or in STV/IRV it may hurt that candidate's chances of winning or not affect it at all. Are you saying that the candidates don't understand the system either (or at least don't understand the best way to get elected)? Polls aren't accurate enough to take advantage of the non-monotonicity. On average, you help a candidate by ranking the candidate higher. Yes, but it certainly advantages the less popular candidates and it certainly is possible for voters of more widely supported candidates to be penalized by it and for nonmonotonicity to cause a majority-opposed candidate win while a majority-favorite loses in STV/IRV. Again, the tread is about the multi-seat PR version. It is impossible to take advantage of lots of very negative things in life, does that mean we should support every negative thing that some advantage can not be planned of it in advance? No, the point is that on average you are better off ranking a preferred candidate higher. I truly don't have time to continue rebutting what I consider to be wholly irrational and worst imaginable method of counting votes, STV/IRV. I think you are letting your dislike for IRV spill over into PR-STV. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR-STV
On Fri, Aug 28, 2009 at 11:08 PM, Kathy Doppkathy.d...@gmail.com wrote: Ralph, I think you've forgotten some crucially important points in your explanation of how STV is counted. My comments below... From: Raph Frank raph...@gmail.com Subject: [EM] Explaining PR-STV PR-STV is based on 4 main principles 1) Each voter gets 1 vote and they can vote for any candidate they want. ** All votes are equal. ** To clarify, add.. All votes are equal... *if* they are counted but some voters' never have their 2nd or 3rd choices counted at all or before their 2nd or 3rd choice candidates are eliminated I think we have a philosophical difference here (in fact, I know we do). You consider each individual ranking a vote. However, I don't look at it that way. Each voter has exactly 1 vote. This vote means that they can increase by 1 the vote total for any candidate. The ranks are not votes, they are just instructions to the counting official on how you want your vote handled. If a candidate is eliminated, you instruct the counter to move you vote to the next highest candidate who is still running. Similarly, if a candidate is elected, you instruct the counter to move the part of your vote that they don't need to the next preference. . often *not true* but it is complex to explain how in STV a candidate with more votes might be eliminated and a candidate with fewer votes win instead due to nonmonotonicity which itself is due to the unequal treatment of voters' votes whereby voters who support the least popular candidates have the most say in which candidates are eliminated, etc. It is true. You won't be eliminated unless you have the least number of votes at that point. 3) If you vote for a losing candidate, your vote is transferred to your next choice This is only true in special circumstances in STV/IRV, namely your vote for a losing candidate is *only transferred to your next choice **if** either: 1. your vote for a losing candidate occurs in early rounds so that your next choice has not yet been eliminated, and Fair enough, I should have said most preferred candidate who has not been eliminated or elected. 2. your vote for a losing candidate is for a losing candidate who does not lose in the final elimination round, in which case your later choices will never be considered. Right, there is up to 1 Droop quota of voters who don't get represented. However, this is much better than potentially 49% of the voters not being represented in a single seat district. This reason for this rule is is so that you can safely give your first choice to your favourite even if he is a weak candidate. This is a wholly, entirely, deceptively false statement. In IRV/STV your first choice vote can always hurt the chances of your 2nd choice candidate winning. Mostly, I don't think non-monotonicity is an issue with PR-STV (or at least the benefits outweigh that disadvantage) Would you prefer the simple version where the 5 candidates who received the most votes in the first round win? That is monotonic, but is much less fair and gives more power to the parties. Yes. this would be more accurately rephrased Be careful to vote for a very very weak candidate first if you do not want your later more popular candidates to lose. Actually, one of the strategies for increasing the power of your vote is to vote for a weak candidate first. Your later more popular candidate will not be eliminated before a weaker but preferred candidate. 4) If you vote for a candidate who gets more votes than he needs, the surplus is transferred to your next choice. Again, this is only true in special situations similar to those mentioned above for having your vote for a losing candidate transferred. Ok, it is only transferred if you have indicated which candidate you want to transfer it to. I don't see how that is unreasonable. You forget to mention that often STV can not fill all the seats unless the quota is reduced to account for all the voters whose ballot choices have been expired or eliminated so that many many voters in STV are prohibited from participating in the final counting rounds. I don't think voters should be required to fill out all their rankings. If voters don't indicate a preference, then that is their choice. Having said that, I would support decreasing the quota on the fly. However, that is just making the method more complex for little benefit. Hence any jurisdiction which has adopted STV have had to eliminate any requirement for majority winners, etc. since the method most often fails to find sufficient candidates that meet the quota. Well, the post is about PR-STV. I agree that in IRV, the disadvantages outweigh the benefits. However, the sheer power that PR-STV gives to the voters outweighs any disadvantages (and the disadvantages are lessened by it being multiseat anyway). It shifts power over candidate selection from party to the voters. totally false
[EM] Explaining PR-STV
One of the hardest parts about PR-STV is actually explaining it. Anyway, this was an approach I was thinking of. I think it hits the main points by covering the reasons rather than the detailed maths. Most people in PR-STV countries understand the method, as they experience it from a voter's perspective, rather than a counter's perspective. PR-STV is based on 4 main principles 1) Each voter gets 1 vote and they can vote for any candidate they want. ** All votes are equal. ** 2) The 5 candidates who get the most votes get a seat. I am assuming 5 seats are to be filled, but the system works for any number. 3) If you vote for a losing candidate, your vote is transferred to your next choice This reason for this rule is is so that you can safely give your first choice to your favourite even if he is a weak candidate. If he doesn't win, your vote will be transferred to your next highest choice, until it gets to a candidate who can win a seat. ** Voting for a weak candidate doesn't mean you are throwing your vote away. ** 4) If you vote for a candidate who gets more votes than he needs, the surplus is transferred to your next choice. The Quota is simply the minimum number of votes a candidate needs in order to be guaranteed to be one of the top 5. If 5 candidates had a quota of votes, then even if all the rest of the votes go to one of the other candidate, he would have less than the quota. If you vote for a candidate and he gets twice the Quota, then he only needs half of your vote to get elected. He keeps half of your vote and the rest of your vote would go to your next choice. ** Voting for a strong candidate also doesn't mean you are throwing your vote away. ** The Ballot The ballot allows the voter the rank the candidates (who is your favourite candidate, who is your next favourite and so on). ** This gives the voter full control over how their vote is transferred. ** The Count In the first round, all the first choices are counted. If no candidate is greater than the quota, then the weakest candidate is eliminated and his votes are transferred. Otherwise, the candidate with more than the quota is declared elected and his surplus votes are transferred. This is repeated round by round until all 5 seats are filled. -- There would need to be a discussion on the loss (or lack thereof) of the local-link due to the larger constituencies and unstable governments. Also, there would need to be a discussion of proportionality. For example, show some first past the post results and some PR-STV country results. Also, there could be a discussion of the effective threshold due to a small number of seats. If there was an example of the count, it might also be worth giving the viewer an example ballot that is his ballot. You could then say stuff like unfortunately, your first choice (A) didn't get elected, so your vote goes to your next choice (B). Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR-STV
This is a very nice, clear explanation or PR-STV. I would suggest mentioning that the quota is commonly set at greater than 1/(N+1) times number of valid votes. Thus, with 5 seats and 600 votes, a candidate who gets more than 100 votes is guaranteed a seat. I'm not convinced that PR can lead to instability. Isn't that more a property of the parliamentary system? After all, in the US we can have congress be at 50/50 Dems/Republicans, where just one defection can swing control to the other side, yet our government doesn't seem all that unstable. Cheers, - Jan On Fri, Aug 28, 2009 at 7:08 AM, Raph Frankraph...@gmail.com wrote: One of the hardest parts about PR-STV is actually explaining it. Anyway, this was an approach I was thinking of. I think it hits the main points by covering the reasons rather than the detailed maths. Most people in PR-STV countries understand the method, as they experience it from a voter's perspective, rather than a counter's perspective. PR-STV is based on 4 main principles 1) Each voter gets 1 vote and they can vote for any candidate they want. ** All votes are equal. ** 2) The 5 candidates who get the most votes get a seat. I am assuming 5 seats are to be filled, but the system works for any number. 3) If you vote for a losing candidate, your vote is transferred to your next choice This reason for this rule is is so that you can safely give your first choice to your favourite even if he is a weak candidate. If he doesn't win, your vote will be transferred to your next highest choice, until it gets to a candidate who can win a seat. ** Voting for a weak candidate doesn't mean you are throwing your vote away. ** 4) If you vote for a candidate who gets more votes than he needs, the surplus is transferred to your next choice. The Quota is simply the minimum number of votes a candidate needs in order to be guaranteed to be one of the top 5. If 5 candidates had a quota of votes, then even if all the rest of the votes go to one of the other candidate, he would have less than the quota. If you vote for a candidate and he gets twice the Quota, then he only needs half of your vote to get elected. He keeps half of your vote and the rest of your vote would go to your next choice. ** Voting for a strong candidate also doesn't mean you are throwing your vote away. ** The Ballot The ballot allows the voter the rank the candidates (who is your favourite candidate, who is your next favourite and so on). ** This gives the voter full control over how their vote is transferred. ** The Count In the first round, all the first choices are counted. If no candidate is greater than the quota, then the weakest candidate is eliminated and his votes are transferred. Otherwise, the candidate with more than the quota is declared elected and his surplus votes are transferred. This is repeated round by round until all 5 seats are filled. -- There would need to be a discussion on the loss (or lack thereof) of the local-link due to the larger constituencies and unstable governments. Also, there would need to be a discussion of proportionality. For example, show some first past the post results and some PR-STV country results. Also, there could be a discussion of the effective threshold due to a small number of seats. If there was an example of the count, it might also be worth giving the viewer an example ballot that is his ballot. You could then say stuff like unfortunately, your first choice (A) didn't get elected, so your vote goes to your next choice (B). Election-Methods mailing list - see http://electorama.com/em for list info Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR-STV
On Fri, Aug 28, 2009 at 3:30 PM, Jan Kokjan.kok...@gmail.com wrote: This is a very nice, clear explanation or PR-STV. Thanks. My aim was to get down to the reasons for each of the rules. PR-STV is an attempt to solve the issues with PR-SNTV. I would suggest mentioning that the quota is commonly set at greater than 1/(N+1) times number of valid votes. Thus, with 5 seats and 600 votes, a candidate who gets more than 100 votes is guaranteed a seat. I was aiming for zero maths formulas. I am not sure how much it really adds. The important point is that the quota is the number of votes you need to be sure of being guaranteed to be 5th or better. The exact way of calculating it is not important. Anyone interested in the maths would be able to work it out pretty quickly from If 5 candidates had a quota of votes, then even if all the rest of the votes go to one of the other candidate, he would have less than the quota. Also, the way I define it, the Droop quota is the only one which meets the condition. I'm not convinced that PR can lead to instability. Isn't that more a property of the parliamentary system? After all, in the US we can have congress be at 50/50 Dems/Republicans, where just one defection can swing control to the other side, yet our government doesn't seem all that unstable. Plurality will take a 55 to 45 split in support and magnify that into say a 65 to 35 split in seats. However, PR with lots of parties is less likely to swing to extremes. If a centerist party holds balance of power, then if they shift support the resulting government will still probably be generally centerist (just leaning in the other direction). I think also the point is that if a small party ends up with balance of power, that creates an incentive for new parties (and independents) to arise. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR-STV
Good Afternoon, Raph Thank you very much for that description of PR-STV. It is so clear that even I can understand it. Fred Gohlke Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR-STV
Ralph, I think you've forgotten some crucially important points in your explanation of how STV is counted. My comments below... From: Raph Frank raph...@gmail.com Subject: [EM] Explaining PR-STV PR-STV is based on 4 main principles 1) Each voter gets 1 vote and they can vote for any candidate they want. ** All votes are equal. ** To clarify, add.. All votes are equal... *if* they are counted but some voters' never have their 2nd or 3rd choices counted at all or before their 2nd or 3rd choice candidates are eliminated. 2) The 5 candidates who get the most votes get a seat. often *not true* but it is complex to explain how in STV a candidate with more votes might be eliminated and a candidate with fewer votes win instead due to nonmonotonicity which itself is due to the unequal treatment of voters' votes whereby voters who support the least popular candidates have the most say in which candidates are eliminated, etc. I am assuming 5 seats are to be filled, but the system works for any number. 3) If you vote for a losing candidate, your vote is transferred to your next choice This is only true in special circumstances in STV/IRV, namely your vote for a losing candidate is *only transferred to your next choice **if** either: 1. your vote for a losing candidate occurs in early rounds so that your next choice has not yet been eliminated, and 2. your vote for a losing candidate is for a losing candidate who does not lose in the final elimination round, in which case your later choices will never be considered. (in other words, it is more accurate to say that in STV if your vote for a losing candidate is for one of the least popular losing candidates who is eliminated early on, then your vote will be transferred to your next choice.) This reason for this rule is is so that you can safely give your first choice to your favourite even if he is a weak candidate. This is a wholly, entirely, deceptively false statement. In IRV/STV your first choice vote can always hurt the chances of your 2nd choice candidate winning. If he doesn't win, your vote will be transferred to your next highest choice, until it gets to a candidate who can win a seat. ** Voting for a weak candidate doesn't mean you are throwing your vote away. ** Yes. this would be more accurately rephrased Be careful to vote for a very very weak candidate first if you do not want your later more popular candidates to lose. 4) If you vote for a candidate who gets more votes than he needs, the surplus is transferred to your next choice. Again, this is only true in special situations similar to those mentioned above for having your vote for a losing candidate transferred. The Quota is simply the minimum number of votes a candidate needs in order to be guaranteed to be one of the top 5. If 5 candidates had a quota of votes, then even if all the rest of the votes go to one of the other candidate, he would have less than the quota. You forget to mention that often STV can not fill all the seats unless the quota is reduced to account for all the voters whose ballot choices have been expired or eliminated so that many many voters in STV are prohibited from participating in the final counting rounds. Hence any jurisdiction which has adopted STV have had to eliminate any requirement for majority winners, etc. since the method most often fails to find sufficient candidates that meet the quota. If you vote for a candidate and he gets twice the Quota, then he only needs half of your vote to get elected. He keeps half of your vote and the rest of your vote would go to your next choice. ** Voting for a strong candidate also doesn't mean you are throwing your vote away. ** totally false statement depending on the definition of strong. There are many examples where voters in STV are only allowed to have a vote counted for one candidate even though they are supposed to be electing a multi-seat *at-large* council, or where the *strong* candidate makes it to the final counting round and then loses, where a *strong* candidate (the first choice of *all* voters in a pairwise comparison) is eliminated in an early round and a less *strong* candidate wins, etc. etc. I don't have time to finish rebutting this plethora of misinformation, but no one should be fooled by it. Cheers, -- Kathy Dopp Town of Colonie, NY 12304 phone 518-952-4030 cell 518-505-0220 http://utahcountvotes.org http://electionmathematics.org http://kathydopp.com/serendipity/ Realities Mar Instant Runoff Voting - 18 Flaws and 4 Benefits http://electionmathematics.org/ucvAnalysis/US/RCV-IRV/InstantRunoffVotingFlaws.pdf Voters Have Reason to Worry http://utahcountvotes.org/UT/UtahCountVotes-ThadHall-Response.pdf Checking election outcome accuracy --- Post-election audit sampling http://electionmathematics.org/em-audits/US/PEAuditSamplingMethods.pdf Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR-STV
Hallo,
I would explain proportional representaion
by the single transferable vote as follows:
1) Each voter gets a complete list of all
candidates and ranks these candidates in
order of preference.
2) Suppose M is the number of seats and
V is the number of votes. If there is a
set of X candidates such that strictly more
than (Y*V)/(M+1) votes strictly prefer
each candidate of this set to each candidate
outside this set, then at least min{X,Y}
candidates of this set must be elected.
Markus Schulze
Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Explaining PR-STV
Markus Schulze wrote:
Hallo,
I would explain proportional representaion
by the single transferable vote as follows:
1) Each voter gets a complete list of all
candidates and ranks these candidates in
order of preference.
2) Suppose M is the number of seats and
V is the number of votes. If there is a
set of X candidates such that strictly more
than (Y*V)/(M+1) votes strictly prefer
each candidate of this set to each candidate
outside this set, then at least min{X,Y}
candidates of this set must be elected.
Isn't that true of all methods that obey the Droop proportionality
criterion (including your own STV variant, which does not transfer any
ballots)?
Election-Methods mailing list - see http://electorama.com/em for list info
