[EM] SODA

[fsimmons at pcc.edu]

I thought that A was required to make her approvals consistent with her ordering, i.e. to approve 
everybody ranked above her cutoff.  Doesn't that mean she is required to approve herself?

Maybe I'm thinking of an older version of SODA.

I hope you are right that there is nothing to fix.


----- Original Message -----
From: Jameson Quinn 
Date: Tuesday, July 5, 2011 1:07 pm
Subject: Re: [EM] SODA
To: fsimmons at pcc.edu
Cc: election-methods at lists.electorama.com

> 2011/7/5 
> 
> > Jameson suggested that the SODA candidates make their approval 
> decisions> sequentially instead of
> > simultaneously.
> >
> > The problem with this is that if a winning candidate moves to 
> first place
> > in the sequence by an increase
> > in support, she may become a losing candidate:
> >
> > Assume sincere preferences are
> >
> > 35 A>B>C
> > 34 B>C>A
> > 31 C>A>B
> >
> > If approval decisions are made in descending order of faction 
> size A, B, C,
> > then B wins.
> >
> > If B gains more support so that the totals become
> >
> > 34 A>B>C
> > 35 B>C>A
> > 31 C>A>B,
> >
> > the sequential order becomes B, A, C, and the winner will be C.
> >
> 
> No. B still wins. If A feels that C is winning, then A can 
> delegate to B,
> and then B cannot lose. So C cannot be the winner. And therefore 
> B will
> delegate to C, to force A's hand. Whether or not C delegates 
> then is
> irrelevant.
> 
> Of course, if A actually prefers C to B, and has managed to keep 
> B ignorant
> of this fact, then C will win. But then, in such a case, A could 
> have gotten
> the same result by being honest from the start.
> 
> >
> >
> > How can we fix this?
> >
> >
> I don't think there's anything that needs fixing, though you may find
> another example to show I'm wrong.
> 
> 
> > How about allowing the largest faction (in this example 49 C) 
> to go second,
> > and making the second
> > largest faction (in this example 27 A>B) go first?
> >
> > That would also work in the example above. How bad would it 
> be in a worst
> > case example?
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> >
>