On Jan 21, 2010, at 1:03 AM, Juho wrote: > What is good in all the common Condorcet methods is that their > vulnerabilities to strategies (and their differences in general) may very > well be so small in typical real elections (large, public, with independent > voter decision making, with changing opinions and less than perfect poll > information) that strategic voting will not be a problem. Also their > differences with sincere votes (e.g. spoiler related problems) are quite > small in real life elections. > > Here's one simple spoiler related example as a response to Kathy Dopp's > request. > > 35: A>B>C > 33: B>C>A > 32: C>A>B > > I this example there are three candidates in a top level cycle. If any of the > candidates would not run that would mean that there is a Condorcet winner, > and that winner would be different in each case. Let's say that the method we > use will pick A as the winner. If B would not run then the votes would be 35: > A>C, 33: C>A, 32: C>A and C would win. B is thus a spoiler from C's point of > view. > > I note however that these spoiler cases in Condorcet are not as common as in > many of the other methods. In practice it may be that there is no need to > worry about these cases. Maybe Kathy Dopp's comparisons will reveal something > about how problematic the spoiler effect is or is not in Condorcet. Not also > that in the example above B was not a minor party candidate (often term > spoiler refers to minor candidates) but a pretty strong candidate.
In that case it might be a good starting point to define "spoiler", so we know what we've found when we find it. What's an example of an IRV spoiler who's not a "pretty strong candidate"? ---- Election-Methods mailing list - see http://electorama.com/em for list info
