<HTML><FONT FACE=arial,helvetica><FONT SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">Kevin Venzke wrote:<BR>
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>Are you looking to show that Plurality, for example, is more likely to be<BR>
>proportional<BR>
>than Condorcet? Random Ballot is easily more proportional than that. Better<BR>
>yet,<BR>
>put a PR method in your model.<BR>
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The one thing the model has demonstrated clearly than anything else is the truth of what myself and a number of other people on the list have been saying for a long time - an assembly made up of single seats can be proportional only by chance. <BR>
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Which single seat method you use can have a considerable effect on the make-up of the assembly though. Plurality is neutral as regards where parties are positioned on a left-right spectrum, IRV is favourable towards centrists, Approval ( with all voters using strategy A once) and Condorcet are more favourable to centrist parties and also extremely similar. Borda (which tends to be unpredictable and throw up a minority of odd results) is most favourable to centrists.<BR>
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Adding a PR method is good idea.<BR>
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>> I wanted to use in my model an Approval strategy which Approval supporters (<BR>
>> of which I am not one) say will give a result that is satisfactory to the<BR>
>> voters. I decided to use Rob LeGrand's strategy A. Rob said the following<BR>
about<BR>
>> strategy A:<BR>
>><BR>
>> > Strategy A: Approve all candidates I prefer to the current CRAB<BR>
>> > first-placer; also approve the first-placer if I prefer him to the<BR>
>> > second-placer.<BR>
> >><BR>
>> > [S]trategy A always homes in on the Condorcet winner when one exists<BR>
>> > and all voters use the same strategy.<BR>
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>I have a hard time calling this an Approval strategy, since it seems to require<BR>
>that CRAB be implemented...<BR>
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Actually ( and bear in mind I am not an Approval supporter) strategy A is an extremely effective method of finding the Condorcet winner if there is one. I recently did a test comparing the result using strategy A based on a single Approval poll with the Condorcet result. Out of 250 seats 240 had a clear Condorcet winner and strategy A found the Condorcet winner in 233 of them (97%).<BR>
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>I suspect you won't be able to model Approval convincingly, if the only<BR>
>information to begin with is rankings.<BR>
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It is certainly complicated to model Approval from ranked ballot information, my original idea was to have logical/strategic and illogical/non-strategic voters. A certain proportion of the voter could be 'set' to use an Approval strategy that Approval supporters consider good (the logical/strategic voter) with the remaining voters (the illogical/non-strategic voter) voting for every candidate they approve.<BR>
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David Gamble<BR>
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