On Sat, 22 Dec 2007 19:46:07 -0000 James Gilmour wrote: >>On Dec 22, 2007, at 6:45 AM, James Gilmour wrote: >> >>>If you wish to utilise in some way all the information that could be >>>recorded on a preferential ballot, that is a completely >>>different voting system from IRV, with different objectives. The >>>preferences are no longer 'contingency choices', but take on a new >>>function depending on the detail of the voting system. It is almost >>>certain that the voters would mark their ballots in a different >>>way in an election by such a voting system from how they would mark >>>their contingency choices in an election by IRV. >> > > Jonathan Lundell > Sent: 22 December 2007 19:00 > >>This seems plausible enough (and certainly IRV voters should be >>instructed along contingency lines). WRT marking ballots differently, >>setting manipulation aside, and considering only contingency vs >>preferential ranking, do you have an example or two of how and why a >>voter might end up with different ballots in the two contexts? > > > That is a very fair question, Jonathan, but I do not have any practical > examples to indicate the circumstances in which voters might > mark their preferences differently. We do not use IRV for any public > elections in the UK and so I have no real example to draw on. > And it is very difficult to invent examples based on direct, single-winner > elections from other countries without a lot of relevant > political information, because there is little agreement about how real > voters would respond, as I have seen repeatedly in > discussions of such examples as Bush-Nader-Gore. I am not a specialist in > voter behaviour and so have no special insights on which > to base "real" predictions. > > That said, one situation where IRV ballots and Condorcet ballots might be > completed similarly would be when there are three strong > front-runners. Then IRV voters and Condorcet voters might well complete > their preferential ballots similarly. When the "everyone's > second choice" candidate had very weak first preference support, they might > well complete the ballots differently: in Condorcet the > supporters of the two strong wings might truncate in an attempt to prevent > the weak second choice from coming through the middle. > But that suggestion is contentious, as I have seen in other discussions and > there is no agreement about how voters would really > react. > > Just a word about terminology: IRV ballots, Condorcet ballots and Borda > ballots are all 'preferential' ballots. The difference is > that in IRV the successive preferences are brought into play only on the > stated contingency; Borda tries to sum all the preferences > instantly into one value; Condorcet perhaps lies somewhere between these two > extremes, depending on the sequence of events in the > individual count.
Out of all this I see very little possible use for differences: All three want the same information about ranking. Borda extracts numeric rank information - which it can get from the same ballots. Condorcet can and should permit equal ranking of multiple candidates - presumably foreign to the others. > > James Gilmour -- [EMAIL PROTECTED] people.clarityconnect.com/webpages3/davek Dave Ketchum 108 Halstead Ave, Owego, NY 13827-1708 607-687-5026 Do to no one what you would not want done to you. If you want peace, work for justice. ---- Election-Methods mailing list - see http://electorama.com/em for list info