There is no way to accurately determine approval voting results using this input format. About the best you can do is to assume that for the A>B voters, half approve both A and B, and the other half approve only A. This would make approval voting equivalent to Borda, at least where fully ranked ballots are concerned.
Also, I notice that you allow equal last-choice preferences (e.g. A>B=C), but not equal first preferences (A=B>C). Doing one but not the other would bias the results. But then the only reasonable way to handle (A=B>C) for IRV or Plurality would be to assume that half vote one way, and half the other. Since precisely equal preferences are theoretically rare, it might be better just to assume fully ranked preference lists for all voters. Bart [EMAIL PROTECTED] wrote: > > Hello List > > I've recently been working on a spreadsheet model to compare various > different electoral methods. What it does is generate, for a 3 party > election, sets of votes for 50 single member districts, based on an > inputted set of preferences amongst the electorate and then calculate > the results under 11 different electoral systems. > > An inputted set of preferences would be something like: > > A = 43 B = 21 C = 36 > > A = 40 A>B = 55 A>C = 5 > > B = 20 B>A = 30 B>C = 50 > > C = 10 C>A = 5 C>B = 85 > > In this example party A has 43 % of the 1st pref vote, party B has 21 > % of the 1st pref vote and party C 36 %. Of party A voters 40% give > no 2nd preference, 55% give a 2nd preference to B and 5% a second > preference to C, etc. > > It then calculates the results under the following 5 single member > systems: > > Plurality > IRV > Condorcet (Ranked Pairs winning margins) > Borda > Approval > > The following 4 proportional systems by combining the single member > districts: > > D'Hondt Highest Average ( 1 fifty member district) > D'Hondt Highest Average (5 member districts) > STV (5 member districts) > MMP ( 25 single districts, 25 top up seats) > > The following 2 semi-proportional systems: > > MMP ( 40 single districts, 10 top up seats) > IRV+ ( 40 single districts, 10 top up seats) > > And displays the results in summary and detail with a number of > comparisons between the systems. > > I would like volunteers to test this model and give their comments on > it. If you would like a copy of the model to test E-mail me at > > [EMAIL PROTECTED] > > and I will send you one. > > David Gamble ---- Election-methods mailing list - see http://electorama.com/em for list info