> [EMAIL PROTECTED] > Sent: 17 April 2007 09:37 > James Gilmour jgilmour at globalnet.co.uk > > raphfrk at netscape.net> Sent: 16 April 2007 20:08 > > > It might be easier to explain. The real problem with PR-STV is the > > > fractional transfers. They are not very easy to explain. > > > > Fractional transfers are absolutely essential for STV-PR (unless you > > accept a small element of chance). Without the correct transfers of > > surpluses you cannot get a proportional result. Some students' unions > > in the UK use this corrupted version, but it cannot rightly be called > > "STV-PR" because it distorts the proportionality expressed by the > > voters. > >
> It seems to me that this method is pretty close to picking random votes > for the surplus transfers. I am aware of five different methods of transferring surpluses in STV-PR and none of them could properly be described as "picking random votes". That procedure was abandoned a long time ago. The only rules that do not involve fractional transfers are the rules used for elections to the Dáil Éireann. Those rules do involve selecting ballot papers at random, but only after the ballot papers have been sorted into sub-parcels ready for transfer to the next available preference. A proportionate number of papers is then selected at random from each sub-parcel. Thus the effect of random selection is minimised. The ballot papers are transferred at a value of one vote in all circumstances. The other four methods of transferring surpluses (Gregory Method, Inclusive Gregory Method, Weighted Inclusive Gregory Method and Meek) all involve fractional transfers. The principles are not difficult to explain or comprehend. > Once a candidate hits the quota, he stops > getting any additional votes. This is the correct procedure for transfers in accordance with the Dáil Éireann rules and the Gregory Method (last parcel only). But it is not the correct procedure for transfers in accordance with the Weighted Inclusive Gregory Method or Meek.. If applied to either of those methods that procedure would give inconsistent results. (The Inclusive Gregory Method should never be used because it is fundamentally flawed as it violates the "one person, one vote" principle.) > In fact, random selection for surplus > transfers might be an even easier way to explain it. Such an explanation would be both wrong and very unhelpful. The Gregory Method (fractional transfers) was devised in 1880 to remove the element of chance that is unavoidable with any method involving random selection of ballot papers. Most electors would now reject any voting system that depended on random selection. That said, random selection has survived as acceptable in Ireland, though in the refined form described above. When STV-PR was re-introduced into Northern Ireland in 1973, it was the Gregory Method that was adopted. Australia switched to the Gregory Method long ago; they then changed to the (flawed) Inclusive Gregory Method for their Federal Senate elections, but Western Australia has since seen the light and is switching to the Weighted Inclusive Gregory Method for its state elections. In Scotland we shall use the Weighted Inclusive Gregory Method for the Local Government elections that will be held on 3 May. James Gilmour ---- election-methods mailing list - see http://electorama.com/em for list info