Difference between revisions of "Majority Acceptable Score voting"

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* Voters rate candidates 0, 1, or 2.  
 
* Voters rate candidates 0, 1, or 2.  
* Eliminate any candidates with a majority of votes at or below a number, while some other candidate (or candiadates) has a majority strictly above that number. That is, keep only those with the highest median. For instance, any candidate rated 0 by a majority is eliminated, unless that eliminates all candidates.  
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* Any candidate rated 0 by a majority is eliminated, if any would remain.  
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** (If there are any candidates rated 2 by a majority, you should eliminate any who aren't. But a majority-2 candidate would probably win in the next step anyway, so this step is probably superfluous. It's just included because it's part of Bucklin voting, which was used in over a dozen US cities, and thus it gives this method a stronger pedigree.)
 
* Then the points are added up for the remaining candidates, and the highest points wins.
 
* Then the points are added up for the remaining candidates, and the highest points wins.
  

Revision as of 08:03, 19 October 2016

Majority Acceptable Score voting works as described below. Technically speaking, it's the graded Bucklin method which uses 3 grade levels and breaks median ties using Score voting.

  • Voters rate candidates 0, 1, or 2.
  • Any candidate rated 0 by a majority is eliminated, if any would remain.
    • (If there are any candidates rated 2 by a majority, you should eliminate any who aren't. But a majority-2 candidate would probably win in the next step anyway, so this step is probably superfluous. It's just included because it's part of Bucklin voting, which was used in over a dozen US cities, and thus it gives this method a stronger pedigree.)
  • Then the points are added up for the remaining candidates, and the highest points wins.

Blank votes are counted as ratings of 1 or 0 in proportion to the fraction of all voters who gave the candidate a 2. For example, a candidate could not win with more than 71% blank votes, because even if the other 29% are all 2-ratings, that would leave 71%*71%=50.41% 0-votes, enough to eliminate.

Here's a google spreadsheet to calculate results: [1]. On page 2, it has some hypothetical results for the Egypt 2012 election, showing that this system could have elected a reformer over Morsi, despite vote-splitting among the various reformers. IRV could have elected Morsi.