From: Anthony O'Neal <[EMAIL PROTECTED]> > Anthony O'Neal wrote: > > (This is the election I pulled out of the Wikipedia article for > CPO-STV. > > I just didn't feel like making up an election where the results from > > CPO-STV and STV differ right now. If you want to see how > > the results for the CPO-STV and STV results were arrived upon, then > > go to the article) > > > >(PS, does anyone know what the BTR part of BTR-IRV means? > > Honestly, I can't figure it out, but that's what Warren on > Rangevoting.com > > calls it. I'm thinking of changing the name to Majority Elimination > by IRV, > > or ME-IRV, and ME-STV, but if BTR makes more sense...)It is probably "Bottom Two Runoff" or something similar.
>I guess I really need to change the name then, because it's not always a runoff between the bottom two, but a runoff >between the bottom N + 1 (where N is the number of seats in the STV election that are currently needing to be filled). I'm >thinking Single Transferrable Vote with elimination by majorities, although this also doesn't really fit, because it's actually >elimination by the majorities of the Droop Quota. I wonder what would be the best way to do your elimination. Maybe some kind of PR-STV that finds a loser ... highest ranked candidate is eliminated and votes transferred until there is only one candidate left. Hmm, you could even use BTR-STV, though it would become "Best" two runoff -- hows that for confusing the issue. > > Now for this election, using the Hagenbach-Bischoff quota of > votes/seats + 1, > > the amount needed to get elected is 25 votes. So Andrea and Carter > are > > immediately declared elected, as their amount of votes exceeds the > quota. > >> Why not use the Droop quota, that is much fairer? > >I believe you are confused. I interpretted your formula as a c compiler would. I thought: >>Now for this election, using the Hagenbach-Bischoff quota of >> votes/seats + 1, meant (votes/seats) +1 rather than (votes)/(seats + 1) According to wikipedia: Droop quota is 1+ (Votes)/(Seats+1) Hare is (Votes)/(Seats) > You are talking about the Hare quota, which is a rather idealistic attempt to represent all voters. Right, I was saying that if you use the Hare quota, there is a problem. <snip you pointing out the same problem> > However, in recommending quotas I'd probably go with Droop > rather than Hagenbach-Bischoff, because in the extraordinarily > unlikely event where the quotas would give different results in > real elections, having a person elected because more votes > were wasted than needed is quite a bit less catostrophic than > having more people elected than there are seats. Another option is to require Droop for a person to be elected, but then work out the amount of transfer based on the Hagenbach-Bischoff quota. > This brings me to another point, though. Why even transfer surplus votes? Why not simply elect the person with the most > votes, then transfer all of that persons voters votes to the second person on their list at a value of V/M * 2 + 1 (where V is > the value of their ballot, and M is the number of candidates that person has had elected)? Wouldn't V = 1 for all ballots ? Is the formula V/(2*M + 1) ? So, a ballot is worth a different amount based on how many candidates it has elected ? 0 -> 1 1 -> 1/3 2 -> 1/5 3 -> 1/7 etc. How do you work out how many people a vote has elected ? I assume it is all votes in the pile when the candidate is elected (it could be you are considered to elect any elected candidate placed higher than your current candidate). A party with 30% and another with 70% would split a 4 seater as: A1: 30% A2: 0% B1: 70% B2: 0% B3: 0% B1 elected ( 70/3 = 23.3 passed to B2) A1 elected ( 30/3 = 10.0 passed to A2) B2 elected ( 70/5 = 14 passed to B3 ) B3 elected ( 70/7 = 10 passed to B? ) A: 1 B: 3 Now, if party A vote manage and split the vote evenly, it is: A1: 15% A2: 15% B1: 70% B2: 0% B3: 0% B1 elected ( 70/3 = 23.3 passed to B2 ) B2 elected ( 70/5 = 14 passed to B3 ) A1 elected ( 15/3 = 5 passed to A2 ) A2 elected ( 5/5 + 15/3 = 6 passed to A? ) Fairness requires that party B gets 3 seats as they have 3 full Droop quotas. They definately shouldn't have equal representation to a party which only obtained 43% as many votes as they did. The optimal strategy is to evenly split the vote over the number of candidates who are to be elected as transferred votes don't count at full strength. If both parties perfectly split their vote, the result would be: A1: 15% A2: 15% B1: 17.5% B2: 17.5% B3: 17.5% B4: 17.5% B gets 4 elected. So, hmm, it would seem that the optimal strategy is not quite so simple. However, it does seem like vote management matters. Maybe, including the option to for candidates to withdraw would help/solve the problem. ___________________________________________________ Try the New Netscape Mail Today! Virtually Spam-Free | More Storage | Import Your Contact List http://mail.netscape.com ---- election-methods mailing list - see http://electorama.com/em for list info