So MAS doesn't strictly satisfy the CD criterion, but a simple defensive measure by the A faction can keep B from winning; they just have to make sure that B's median score is zero by down voting B on a few ballots. As Michael pointed out recently, plain Range with high resolution ballots provides a similar chicken defense for A. But MAS does the same thing with three slots, so I think it is an improvement. I agree that ICT is better than MAS, but not for public consumption. A more succinct (but equivalent) way to define MAS would be "Elect the candidate with the highest total score among all those tied for highest median score." Jameson's definition is probably better psychologically. A grade ballot version would be "Elect the candidate with the highest average grade among the candidates tied for highest median grade." Regarding the resolution of blanks on MAS style ballots: Let the candidates top rated on the ballot decide between down and middle. Assuming the candidates at least publish an approval ballot before election day, this adjustment could be automated during the count. Michael Ossipoff wrote ... > > Yes, if both factions of the majority (A & B) cooperate by bottom voting C, > but not eachother, then yes, A, the larger faction of the majority, wins. > > But what if B, the other faction of the majority, defects instead of > cooperating? > > They don't rate A or C above bottom. > > Now B is the only candidate not bottom voted by a majority. > > Additionally, B has more points than anyone else. > > B, with fewer voters than A, wins because the A voters cooperated & the B > voters defected. > > In 3-Slot ICT, if the A voters middle-rate B, & the B voters bottom-vote A > (both factions bottom voting C), then C wins. The B voters should have > cooperated to beat C. > > (The C voters bottom-vote A & B). > > Michael Ossipoff > On Oct 6, 2016 11:41 AM, "Jameson Quinn" <jameson.quinn@gmail.com> wrote: > > > I've been working on a simple three-slot system as a next step after > > approval. This has gone through various iterations and names: U/P, MUMA, > > NUMA. The latest, and I hope final, version is MAS, Majority Acceptable > > Score. Here's an explanation, intended for those without a voting theory > > background. The basic system is described in 3 sentences in the first > > paragraph; the second paragraph describes the default rule, which is > > worthwhile but not absolutely essential to the system; and the next two > > paragraphs give some scenarios. > > > > For each candidate, you may upvote, ?midvote?, or downvote. Candidates > > with a majority of downvotes are eliminated, unless that eliminates > > everyone. The remaining candidates get 2 points for every upvote and 1 > for > > every midvote. Most points wins. > > > > When people leave a candidate blank, that could mean one of two things: > > ?never heard of this person?, which should count as a downvote for > safety; > > or ?no strong feelings?, which should count as a midvote (because if the > > voter really disliked the candidate they would have downvoted). To > > distinguish these possibilities, see if the candidate?s score from > > non-blank votes averages at least half a point per voter; for instance, > > this would be true if they were upvoted by 25%, or explicitly midvoted by > > 50%. If the score is this good, that candidate is reasonably well-known > and > > well-liked, so blanks count as midvotes; if it isn?t, that candidate is > > relatively unknown, so blanks count as downvotes. > > > > MAS is good at dealing with a vote-splitting situation ("chicken > dilemma", > > so called because in many voting systems it can work like a game of > chicken > > between the two majority subfactions). Say that one "side" of voters have > > 55%, but there are two candidates on that side splitting the vote and > only > > one on the other side. In this case, assuming voters on either side > > downvote the candidates on the other side, the 45% candidate will be > > eliminated by downvotes, and whichever subfaction of the majority has > more > > supporters will win. > > > > MAS also deals well with a "center squeeze" scenario, in which a centrist > > candidate faces off against candidates on either side. Assuming all three > > are equally qualified and likeable, the centrist will probably be able to > > beat either side in a one-on-one race (because leftist voters will prefer > > Center over Right, and vice versa); but it is quite possible that there > > will be more partisans on either side than in the center. In this case, > the > > centrist should not be punished simply for being more "crowded" > > ideologically; their ability to dominate one-on-one means they should > win. > > But many voting systems, such as IRV, can eliminate the centrist > > prematurely, giving results like the tragic outcome in Egypt 2012. > > Meanwhile, other systems, such as Condorcet, can enable tricky strategies > > by one side to possibly win. In MAS, as long as the center candidate was > > preferred by a respectable number of voters (say, 20% or more), > "midvotes" > > from voters in either wing would probably be enough to let the centrist > > win; and *either* defensive "midvoting" from the weaker wing or defensive > > "downvoting" by the centrists would probably be enough to stop a takeover > > by the stronger wing. >

On Oct 7, 2016 1:32 PM, "Forest Simmons" <fsimmons@pcc.edu> wrote: > > So MAS doesn't strictly satisfy the CD criterion, but a simple defensive measure by the A faction can keep B from winning; they just have to make sure that B's median score is zero by down voting B on a few ballots. (endquote) Yes, but when it's necessary for a certain fraction of the A voters to vote differently from the rest, that will require either 1) probabilistic voting by all the A voters; or 2) a party of campaign organization instructing people to not support B if they reside within certain street-boundaries of if their name alphabetizes between two specified other names. So, maybe the ICT count-rule needs more explanation, but probabilistic voting, or special voting instructions based on name of neighborhood makes more work for voters. A little more explanation can buy something easier to use. > > As Michael pointed out recently, plain Range with high resolution ballots provides a similar chicken defense for A. But MAS does the same thing with three slots, so I think it is an improvement. > > I agree that ICT is better than MAS, but not for public consumption. A proposer could say: We look at pairwise comparisons. X beats Y if: The number of people ranking X over Y is greater than the number of people ranking Y over X, + the number ranking both at top. So, if you rank them both at top, you're voting against either beating the other. We do that so that you can fully support & protect as many candidates as you want to, by top-ranking them. The winner is the unbeaten candidate who is top-ranked by the most people. If no one is unbeaten, the winner is the candidate top-ranked by the most people. (end of introduction/definition) Well yes, I tried that introduction, and it didn't go over well. I said, "If someone you didn't know came up to you with a clipboard, on a street-corner, gave that introduction, & invited you to sign the initiative petition for it, would you sign it?" Answer: "No" MMPO has a very brief & obvious definition, but the objections to it must be disclosed & answered, to the initiative-comittee at least. Maybe Approval, but a lot of people reject it, perceiving it as illegal Plurality. Maybe Score. If people prefer unlimited rankings, then maybe Bucklin. It's use-precedent in at least 39 cities would help. I regard voting system proposals, now, as a way to get people's attention to a problem for which the 1st need is verifiable vote-counting. Michael Ossipoff > > A more succinct (but equivalent) way to define MAS would be "Elect the candidate with the highest total score among all those tied for highest median score." > > Jameson's definition is probably better psychologically. > > A grade ballot version would be "Elect the candidate with the highest average grade among the candidates tied for highest median grade." > > Regarding the resolution of blanks on MAS style ballots: Let the candidates top rated on the ballot decide between down and middle. Assuming the candidates at least publish an approval ballot before election day, this adjustment could be automated during the count. > > Michael Ossipoff wrote ... >> >> >> Yes, if both factions of the majority (A & B) cooperate by bottom voting C, >> but not eachother, then yes, A, the larger faction of the majority, wins. >> >> But what if B, the other faction of the majority, defects instead of >> cooperating? >> >> They don't rate A or C above bottom. >> >> Now B is the only candidate not bottom voted by a majority. >> >> Additionally, B has more points than anyone else. >> >> B, with fewer voters than A, wins because the A voters cooperated & the B >> voters defected. >> >> In 3-Slot ICT, if the A voters middle-rate B, & the B voters bottom-vote A >> (both factions bottom voting C), then C wins. The B voters should have >> cooperated to beat C. >> >> (The C voters bottom-vote A & B). >> >> Michael Ossipoff >> On Oct 6, 2016 11:41 AM, "Jameson Quinn" <jameson.quinn@gmail.com> wrote: >> >> > I've been working on a simple three-slot system as a next step after >> > approval. This has gone through various iterations and names: U/P, MUMA, >> > NUMA. The latest, and I hope final, version is MAS, Majority Acceptable >> > Score. Here's an explanation, intended for those without a voting theory >> > background. The basic system is described in 3 sentences in the first >> > paragraph; the second paragraph describes the default rule, which is >> > worthwhile but not absolutely essential to the system; and the next two >> > paragraphs give some scenarios. >> > >> > For each candidate, you may upvote, ?midvote?, or downvote. Candidates >> > with a majority of downvotes are eliminated, unless that eliminates >> > everyone. The remaining candidates get 2 points for every upvote and 1 for >> > every midvote. Most points wins. >> > >> > When people leave a candidate blank, that could mean one of two things: >> > ?never heard of this person?, which should count as a downvote for safety; >> > or ?no strong feelings?, which should count as a midvote (because if the >> > voter really disliked the candidate they would have downvoted). To >> > distinguish these possibilities, see if the candidate?s score from >> > non-blank votes averages at least half a point per voter; for instance, >> > this would be true if they were upvoted by 25%, or explicitly midvoted by >> > 50%. If the score is this good, that candidate is reasonably well-known and >> > well-liked, so blanks count as midvotes; if it isn?t, that candidate is >> > relatively unknown, so blanks count as downvotes. >> > >> > MAS is good at dealing with a vote-splitting situation ("chicken dilemma", >> > so called because in many voting systems it can work like a game of chicken >> > between the two majority subfactions). Say that one "side" of voters have >> > 55%, but there are two candidates on that side splitting the vote and only >> > one on the other side. In this case, assuming voters on either side >> > downvote the candidates on the other side, the 45% candidate will be >> > eliminated by downvotes, and whichever subfaction of the majority has more >> > supporters will win. >> > >> > MAS also deals well with a "center squeeze" scenario, in which a centrist >> > candidate faces off against candidates on either side. Assuming all three >> > are equally qualified and likeable, the centrist will probably be able to >> > beat either side in a one-on-one race (because leftist voters will prefer >> > Center over Right, and vice versa); but it is quite possible that there >> > will be more partisans on either side than in the center. In this case, the >> > centrist should not be punished simply for being more "crowded" >> > ideologically; their ability to dominate one-on-one means they should win. >> > But many voting systems, such as IRV, can eliminate the centrist >> > prematurely, giving results like the tragic outcome in Egypt 2012. >> > Meanwhile, other systems, such as Condorcet, can enable tricky strategies >> > by one side to possibly win. In MAS, as long as the center candidate was >> > preferred by a respectable number of voters (say, 20% or more), "midvotes" >> > from voters in either wing would probably be enough to let the centrist >> > win; and *either* defensive "midvoting" from the weaker wing or defensive >> > "downvoting" by the centrists would probably be enough to stop a takeover >> > by the stronger wing. > > > > ---- > Election-Methods mailing list - see http://electorama.com/em for list info >