02/28/02 - Successive Quota Surpluses for STV and IRVing: Dear Tom Ruen,
Back on the 26th of January, when I answered your post about `vote splitting', there was another solution that I had forgotten about. That solution goes by the title of: Successive Quota Surpluses for STV. The method uses a different math to decide which candidate is to be eliminated. It uses a form of STV with a different quota. The quota is not based on the number of seats, it is based on the number of remaining candidates as follows: Total Voters less any Exhausted Ballots Quota equals: ----------------------------------------- plus one Remaining Candidates The method starts with the quota equal to total votes divided by all the candidates, then one is added. The surplus votes are transferred and the lowest candidate is eliminated from the original data. A new quota is calculated and again surplus votes are transferred and again the lowest candidate is eliminated from the original data less the first candidate eliminated, etc, etc, until the remaining candidates equals the number of seats. This method can also be used for IRVing. I don't know when you first joined the STV list, but back in Dec of 2001, this method was discussed. I copy two of the posts below to bring you up to speed. You will notice that Steve Todd claims that: "This is not a good way to elect a committee, council, legislature, etc...", but he gave no reason nor proof except to make a pitch for his Meek-STV. Until a valid reason or proof comes forward, I feel we are free to consider this method in both Preference Voting/STV and IRVing. Regards, Donald - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - From: "Richard Lung" <[EMAIL PROTECTED]>, Date: Sun, 2 Dec 2001 Subject: [stv-voting] Successive quota surpluses STV It seems to me that the most thoro STV count would involve a series of elections that eliminated one candidate at a time thru the agency of transfering surplus votes, as far as possible. For example, there are seven candidates for three seats. Instead of setting the Droop quota at one quarter of the votes, there would be a series of rounds starting with a quota of one-seventh the voters. The idea of this would be that when the surplus transfers had been exhausted, the trailing candidate would be eliminated. Then the quota would be lowered to one sixth and the process repeated till the elective one-quarter of the votes quota settled who got the three seats going. Obviously, such a systematic method would require a computer count. <snip text about Meek> Yours sincerely, Richard Lung. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - To: [EMAIL PROTECTED], From: "Steve Todd" <[EMAIL PROTECTED]> Date: Fri, 07 Dec 2001 Subject: Re: [stv-voting] Successive quota surpluses STV Richard-- You are proposing a system that I call STV(SE), i.e. STV with successive exclusion (from the bottom up). It is the best way for political parties to construct an ordered candidate list to contest elections under PR systems such as pure List, MMP / AMS. If you are ordering a list of 10 candidates, the first 'election' is for 9 seats (Droop quota of one-tenth). The loser goes to No. 10 on the list. The loser is excluded from the process. Any votes given for the loser are transferred to second preferences. The second 'election' now involves 9 candidates going for 8 seats (Droop quota of one-ninth). The loser goes to No. 9 on the list, and so on. This method will be used by 3 political parties in New Zealand during the first half of next year, in preparation for our next general election (probably in late-November 2002). In fact, they will be using Meek-STV(SE) to construct their (indicative) lists, meaning a computer will definitely be used. The method does not violate later-no-harm within each STV 'election', but, as Joe says, across all rounds of counting, it can. It does have one advantage, though. It generally ensures that the Condorcet candidate (if there is one), who may not have a great number of first-preference votes, will come through to head the list. This is not a good way to elect a committee, council, legislature, etc. of (say) 5 or 6 members from (say) 12 to 20 candidates. Meek-STV is best for that, bearing in mind that voters in STV elections are looking to elect the required number of candidates, who will have EQUAL STATUS. Steve - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Regards, Donald Davison, host of New Democracy at http://www.mich.com/~donald +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ | Q U O T A T I O N | | "Democracy is a beautiful thing, | | except that part about letting just any old yokel vote." | | - Age 10 - | +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ APV Approval Voting ATV Alternative Vote aka IRV Instant Runoff Voting aka IRVing FPTP First Past The Post aka Plurality NOTA None of the Above aka RON Re-Open Nominations STV Single Transferable Vote aka Preference Voting aka Choice Voting aka Hare Clarke aka Hare Preferential Voting Please be advised that sending email to me allows me to quote from it and/or forward the entire email to others.