I would like to see how the Yee/BOlsen diagrams for this method compare with those of IRNR (Instant Runoff by Normalized Ratings), for example.
Chris Benham wrote: >Hello, >My current favourite plain ranked-ballot method is "Approval-Sorted >Margins(Ranking) Elimination": > >1. Voters rank candidates, truncation and equal-ranking allowed. > >2. Interpreting ranking above bottom or equal-bottom as 'approval', >initially order the candidates >according to their approval scores from the most approved (highest >ordered) to the least approved >(lowest ordered). > >3. If any candidate Y pairwise beats the candidate next highest in the >order (X) , then modify the order >by switching the order of the X>Y pair (to Y>X) that are closest in >approval score. >Repeat until all the candidates not ordered top are pairwise beaten by >the next highest-ordered candidate. > >4. Eliminate and drop from the ballots the (now) lowest ordered candidate. > >5. Repeat steps 2-4 until one candidate (the winner) remains. > > >Simply electing the highest ordered candidate after step3 is ASM(Ranking): > >http://wiki.electorama.com/wiki/Approval_Sorted_Margins > >> First "seed" the list in approval order. Then while any alternative X >> pairwise defeats the alternative Y >> immediately above it in the list, find the X and Y of this type that >> have the least difference D in approval, >> and modify the list by swapping X and Y. > >It is equivalent to ASM(R) in the situation where there are three >candidates in the top cycle with no voter >ranking all three above bottom (and in any election with just three >candidates). > >The advantage of this over ASM(R) is that there is less truncation >incentive and voters who rank all the >viable candidates plus one or more others will normally face little or >no disadvantage compared to informed >strategists. At some point in the process all except the candidates in >the top-cycle will be eliminated, and >assuming three remain then from that point it will proceed like an >ASM(R) election as though the "over-rankers" >'approve' their two most preferred candidates (of the 3 in the top cycle). > >An advantage it has over Winning Votes (BP, RP,River) is that it >doesn't have a 0-info. random-fill incentive. >Also unlike both WV and Margins it meets the Possible Approval Winner >(PAW) criterion. > >35: A >10: A=B >30: B>C >25: C > >C>A 55-45, A>B 35-30, B>C 40-25. > >In this Kevin Venzke example, if we assume that voters rank all approved >candidates strictly above all others >then it isn't possible for B to be approved on more ballots than A. WV >and Margins elect B. > >ASM(R)E, like ASM(R) and DMC(R), elects C. > >It seems obvious that ASM(R)E meets Minimal Defense. >http://nodesiege.tripod.com/elections/#critmd >// >If more than half of the voters rank candidate A above candidate B, and >don't rank candidate B above >anyone, then candidate B must be elected with 0% probability.// > >Referring to this definition, while A and B remain uneliminated A will >always be considered to be more 'approved' >than B and of course A pairwise beats B, so B will always be ordered >below A and so must at some point be >eliminated. > >Chris Benham > >// > > > > ---- election-methods mailing list - see http://electorama.com/em for list info