[EM]

[Forest Simmons]

On Thu, 15 Mar 2001, MIKE OSSIPOFF wrote (in part):

> 
> WDSC says:
> 
> If a  majority of all the voters prefer Smith to Jones, then they
> should have a way of voting that will ensure that Jones won't win,
> without any member of that majority reversing a sincere pairwise
> preference ordering.
> 
> [end of definition]
> 

  (...)
> 
> I once proposed that Seeded Condorcet method to a meeting, in '86.
> They had to take a vote, and a few people were proposing voting systems
> different from the one that they usually used. They didn't accept my
> suggestion.
> 
> A better name might be Approval-seeded SP (Sequential Pairwise).
> 
> But that method doesn't ensure something important that Condorcet
> ensures:
> 
> With Condorcet, if a majority prefer the sincere CW to Jones, they
> can make Jones lose by merely voting sincerely, provided that no
> one falsifies a preference.
> 
> That isn't true with Approval-Seeded SP. And what if someone _does_
> falsify a preference? Then Approval-Seeded SP can fail WDSC.
> 
> Say there are 3 candidates, and your favorite comes in "middle" in
> the Approval count. Your favorite is B.
> 
> B is sincere CW--is preferred to both A & C by more voters than vice-versa. 
> A pairwise beats C.
> 

If B is the sincere CW under Condorcet, then she will win in Approval
Seeded SP, at least my version. Whether B starts in the middle or the
bottom of the seeded list, she will win every pairwise comparison all of
the way to the top. 

You must be thinking of something else.


> The Approval finishing order is
> A, B, C. Some A voters truncate in the BC election. So, even though
> B is sincere CW, B loses to C.
> 
> When C goes agains A, A wins.

In my version, A loses to B, so A stays at the bottom and is never
compared to C.

Again, I think you're talking about some other way of using the Approval
Seeded list.

> That's a violation of SFC. Anything
> that violates SFC is also violating GSFC, a generalization of SFC.
> 
> That can happen when everyone who prefers B to A votes sincerely.
> 
> If the A voters instead order-reverse against B in the BC vote,
> it can become necessary for members of the B>A majority to reverse
> a sincere preference in order to keep A from winning, and so WDSC
> is violated too.
> 
> Condorcetists & Approvalists have good reasons for advocating those
> methods.
> 
> Mike Ossipoff
> 


Forest