On Sun, 2007-02-11 at 12:14 -0500, Warren Smith wrote: > >Ritchie: > Strategy in Condorcet... order reversal? > > --WDS: > There seems to be the idea in either Ritchie's or other minds > that, if you allow equalities in rankings in a Condorcet voting systems > (and/or, handle them via "winning votes") > then "order reversal" will not be required of a strategic voter. > > I believe that idea is false. I suspect that in every Condorcet system, > whether > rank-equalities are allowed or not, and whether "winning-votes" are used or > not, > there are election situations where you (a voter or co-feeling small bloc > of voters) must cast a vote which > is fully-dishonest about one or more orderings, i.e in which you say A>B > when you honestly feel B>A. If you do not do this in your vote, > then you get a worse election winner. > > One way to set up such a situation (which should work against most of > the Condorcet systems discussed on EM) is this. > You honestly feel A>C>the other candidates. > If you do nothing or vote honestly, then C will be the Condorcet winner. > If you vote A>the others>C then C will no longer be > the Condorcet winner allowing A to win. > If you rank the others EQUAL to C then C will still be the Condorcet winner. > Huh? I didn't write that.
Anyway, exactly because order reversal IS the strategy to use under Condorcet, people are less likely to do it. It's visibly risky - you're reversing your preferences and going for broke on your top choice. You need some important information to do this - namely that C will be the Condorcet winner. All that makes it "harder" to vote strategically in Condorcet. Thanks, Scott Ritchie ---- election-methods mailing list - see http://electorama.com/em for list info
