fsimmons at pcc.edu fsimmons at pcc.edu
Tue Jan 10 15:46:08 PST 2012


Here's why I think that the CLD part is not necessary when we limit MMPO to three slots:

The most likely situation where the CL wins is the case in which there is a clone cycle of three 
candidates that generate a lot of opposition among themselves, more opposition than any of them 
generate against the CL.

When we limit to two slots of approval (and two or fewer slots of disapproval) then there can be no clone 
cycle, assuming that clones are mostly approved together or disapproved together.

So that basically takes care of the CL problem.

AS for Kevin's bad example, I have suggested including the disapprovals as oppositions as well as 
symmetric completion at the bottom.  Either of these by itself will solve the problem, but I think that the 
disapproval idea is easier to sell than explaining why we want symmetric completion at the bottom . but 
not at the top.

49 C
03 A
24 A>B
24 B (>A?)

With the disapprovals included (along the diagonal) with the other pairwise oppositions we get

Oppositions to A are  [ 73, 24, 49]
Oppositions to B are  [ 27, 52, 49]
Oppositions to C are  [ 27, 48, 51],

so C wins.  But if the B supporters give as much support to A as the A supporters have given to B, then 
the 73 disapproval opposition reduces to 49 and A wins with room to spare (a one percent margin).

It also solves the other Kevin bad example

49 A
01 A=C
01 B=C
49 B

The disapproval opposition to C is 98, which makes C the MMPO loser when we include disapproval as 
an opposition, i.s. as the opposition of the "approval cutoff" ideal candidate/level of acceptance.

What do you think?


> To: 
> Subject: [EM] CLDMMPO
> Forest--
> You wrote:
> I wonder if it is possible for a CL to win three slot MMPO when 
> the number of ballots on which X appears 
> in the bottom slot is counted as an oppsitions to X.
> In other words, I wonder if the CL disqualification is redudant 
> in that context.
> Also, how does the CLD rule affect the FBC in general?
> [endquote]
> I too have been concerned that FBC compliance could be affected 
> by CLD, or the other
> disqualification and completion proposals that I've 
> speculatively suggested.
> I suggest that when one method is completed by another, or when 
> there are 
> disqualifications, the "," relation should be used instead of 
> the "//" relation. 
> So, when applying the 2nd method--the completion method, or the 
> method used after
> the disqualifications--the entire initial set of candidates 
> would be used in 
> calculating the scores for the completion or post-
> disqualification method, even
> though that method is applied only to the post-disqualification 
> candidates.
> Doesn't that do a lot to protect FBC compliance.
> I found that CLDMMPO wouldn't avoid Kevin's MMPO bad-example (I 
> mentioned that in
> my other post today). But, as Ted suggested, maybe 3-slot 
> methods can avoid many
> of the problems that can happen with unlimited-ranking methods. 
> So that's another
> thing to investigate. Might 3-slot MMPO be easier to protect 
> from Kevin's 
> bad-example? Is there some easy way to achieve that?
> Mike Ossipoff

More information about the Election-Methods mailing list