[EM] more Condorcet mythology and other information

[Scott Ritchie]

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