[EM] alternative Smith?

[Chris Benham]

James,

Kevin Venzke has shown that we can't have all three of  Minimal Defense, 
Plurality, Later-no-Harm.

I  like these properties, so for a while one of my standards has been 
that a s-w voting method must
meet two of those three.  This standard is met by IRV,  Bucklin,  
WinningVotes  but is failed by
Smith,IRV  and  Margins.

Probably a good  Condorcet method is "MDD,Smith,IRV".

"Unless all the candidates have majority-strength defeats, disqualify 
from winning all those that do.
Also disqualify from winning candidates who are not members of the Smith 
set.
Elect the undisqualified candidate that is highest-ordered by  IRV on 
the original ballots."

The one disadvantage that I can see that this has versus plain 
Smith,IRV  is  that (like  Bucklin and
CDTT methods)  it  fails my  "Irrelevant Ballots" criterion. 

This means that the result can be changed just by a handful of voters 
turning up and doing nothing but
bullet-voting for themselves as write-ins, by  increasing the total 
number of valid ballots and so raising
the majority threshold.

The  advantage gained is  that it meets  MD  and  the  "Strategy-Free 
Criterion" (SFC).

MDD,Smith,IRV  has the same motivation as the  "Smith//MDD//IRV" method  
you suggested  last
December.
http://lists.electorama.com/pipermail/election-methods-electorama.com/2004-December/014275.html

Chris  Benham



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