[EM] Dual Dropping method and "Preference Approval" ballot ideas

Adam Tarr atarr at purdue.edu
Tue Sep 10 09:25:23 PDT 2002


Stephane Rouillon wrote:

> > B>D and D>C; 14-8 each
> > A>C and C>B; 13-9 each   ...and A>D; 13-9
> > B>A; 12-10.
>
>I do obtain the same results than you but not the same last conclusion:
>
>Ranked pair: B>A>D>C
>it overturns C>B (13-9)
>
>SSD: A>D>C>B
>it overturns B>A (12-10) ...but BD (14-8) too!
>Correct me if I am wrong.
>It is not fair to only count overturns related to the winner...

I don't see why I need to consider B>D to be overturned... A is already the 
Condorcet winner if we ignore B>A.  But if I ignore A and search for the 
new Condorcet winner with SSD, I'll overturn C>B just like ranked pairs 
does (not B>D).  After all, there's no difference between RP and SSD in the 
three candidate case.

I'm honestly unsure if the final ranking of the candidates other than the 
winners, and the defeats that need to be overturned to produce such a 
ranking, are at all relevant.  It seems like this is more of a multi-winner 
issue.

-Adam


----
For more information about this list (subscribe, unsubscribe, FAQ, etc), 
please see http://www.eskimo.com/~robla/em



More information about the Election-Methods mailing list