[EM] New criterion: The Co-operation/Defection Criterion

[Kevin Venzke]

Hi Mike,

--- En date de : Lun 24.10.11, MIKE OSSIPOFF <nkklrp at hotmail.com> a écrit :
> Co-operation/Defection Criterion (CD): 
>  
> Premise:
>  
> A majority prefer A and B to everyone else, and the rest of
> the voters all prefer everyone else to A and B.
>  
> Candidate A is the Condorcet candidate
>  
> Voting is sincere except that the B voters (voters
> preferring B to everyone) else refuse to vote A over anyone.
> 
>  
> Requirement:
>  
> The Condorcet candidate wins.
>  
> [end of CD definition]
>  
> I’m only aware of one method that meets CD:  MMPO.

When I simplify this scenario in my head it seems like a combination
of SDSC and SFC. Basically A will have a majority over B, and B will
have a majority over third candidate C (if there are only three), and
A will not have a voted majority over C. A might even lose to C (unless
"Condorcet candidate" is defined on cast votes), but it won't be by a
majority.

In this scenario, SDSC prevents C from winning and SFC prevents B from
winning.

I'm assuming cast ballots look something like this:

48 C>A
~26 A>B
~26 B (sincere is B>A)

Is this wrong?

Kevin