On Nov 2, 2006, at 1:29 , Kevin Venzke wrote: > Juho, > > --- Juho <[EMAIL PROTECTED]> a écrit : >> Example 1. Large party voters consider C better than the other large >> party candidate, but not much. >> >> 45: L>>C>R >> 40: R>>C>L >> 15: C>L=R >> >> Ranked Preferences elects L. (first round: L=-10, C=-70, R=-20; >> second round: L=-10, R=-20) > > In my opinion, if C is able to convince *every voter* to acknowledge > that he is better than the major party alternative, then C is surely > not a bad result.
There is no need to convince every voter. This example is simplified (for readability) but not extreme since there could well be a mixture of different kind of votes. (See e.g. example 4.) The utility of C could be really low to the voters even though it was ranked higher than the worst candidate (in Range terms e.g. R=99, C=1, L=0). One of the key points of Ranked Preferences is that also weak preferences can be expressed and they may have impact. > As long as truncation is allowed, and voters have the opportunity to > learn how the method works, I don't think "weak" CWs would be a real > problem. I take this to mean support to basic (flat preference) Condorcet methods with active use of truncation. > If they're not "good enough" to win at all, people should not > be giving them votes. I'd prefer methods where voters can simply vote sincerely without considering when it is beneficial to truncate and when not. Condorcet voters need not leave non-approved candidates unlisted. I think Ranked Preferences provides some improvements. I'll try to explain. If A and B voters would all truncate we would end up in bullet voting and falling to a plurality style election. Not a good end result. 45: L>C=R 40: R>C=L 15: C>L=R Note also that at the first round vote R>>C>L gives exactly the same results as vote R>C=L. Ranked Preferences thus allows voters to "truncate" and in addition to indicate also the preference order of the "truncated" candidates. The lower strength preferences come into play after the higher strength preferences are no longer used. It is also important from the R supporters' point of view to be able to indicate that C is better than L. They need to be prepared for the situation where R can not win. In example 1 C was eliminated first. With modified votes (see below) R will be eliminated first. Now the lower preferences of the R supporters become important. (first round: L=-10, C=0, R=-20; second round: L=-10, C=0) 20: L>>C>R 25: L>C>>R 30: R>>C>L 10: R>C>>L 15: C>L=R If the 30 R>>C>L voters would have voted R>>C=L (truncated), L would have won. (first round: L=-10, C=0, R=-20; second round: L=-10, C=-50) From the A voters' point of view voting L>>C>R is also quite safe. Ranking C above R in the ballot does not help making C the winner (although it might make C a flat preference Condorcet winner) as long as L is in the game. And if L is eliminated, then these votes will support C over R. I thus claim that truncation as a tool in traditional (flat preference) Condorcet methods is not as expressive and not as natural for the voters than the ranked preferences of the Ranked Preferences method. At least in this example voters clearly benefited of sincere voting. I think it is a problem of basic Condorcet methods that they easily elect the centrist candidate. If preference strengths are not known electing the Condorcet winner is a good choice (and basic Condorcet methods are good methods). If preference strengths are known, then the choice is not that obvious. Ranked Preferences takes into account the relative strength of preferences (but not the "absolute strengths" in the Range style). The end result is more expressive than basic Condorcet but still quite immune to strategies (?). In some cases it allows also even more sincere ballots than the basic Condorcet methods (see above). Juho Laatu Send instant messages to your online friends http://uk.messenger.yahoo.com ---- election-methods mailing list - see http://electorama.com/em for list info
