[EM] MDDA(symmetric completion example)

[Forest Simmons]

I might be missing something but since C is ranked above bottom in the last
two factions, which add up to 54% of the electorate, candidate C would have
more implicit approval than candidate B.

On Tue, Nov 22, 2016 at 5:19 PM, Chris Benham <cbenhamau at yahoo.com.au>
wrote:

> On 11/23/2016 8:22 AM, Forest Simmons wrote:
>
> If the 44 buriers were more conservative in their burial by not approving
> C …
>
>
> 43: A
>
> 03: A>B
>
> 44: B>>C  (sincere is B or B>A)
>
> 10: C
>
>
>
> … then A would win without regard to the convention of the default
> approval cutoff.
>
>
> Forest,
>
> By my calculation B wins if the default approval cutoff is just above
> equal bottom. With the symmetric completion
> at the bottom all three candidates have majority-strength defeats (A>B
> 51-49, B>C 68.5-31.5, C>A 54-46) and the
> Approval scores are  B47 > A46 > C10.
>
> So as in Smith//Approval  B wins.  This is a good example of why Kevin
> Venzke wasn't in favour of allowing voters
> to rank among unapproved candidates (at least under Smith//Approval).
>
> It's also a good advertisement for Approval Sorted Margins, which easily
> elects A.
>
> And it leads me to think that in MDDA(SC) the default approval should only
> be for the top-voted candidates.
>
> Chris Benham
>
>
>
> On 11/23/2016 8:22 AM, Forest Simmons wrote:
>
> Chris,
>
>
>
> Here’s an example that you asked me to look at from last month.
>
>
>
> You wrote ….
>
>
>
> 43: A
>
> 03: A>B
>
> 44: B>C  (sincere is B or B>A)
>
> 10: C
>
>
>
> C>A  54-46,    A>B  46-44,   B>C 47-10.
>
>
>
> Here A is the sincere CW and supported by the largest of the three
>
> factions of voters, but Winning Votes rewards the buriers by electing B.
>
>
>
> Benham and  LV(erw)SME   easily elect  A.    Smith//Approval (equivalent
>
> here to Max Covered Approval) and Approval Sorted Margins elect C.
>
>
>
> [end quote]
>
>
>
> Let’s look at this example from the point of view MDDA(symmetric
> completion):
>
>
> With symmetric completion every candidate is 50% plus defeated, so nobody
> is disqualified, and the approval winner is elected.
>
>
> If the default is to approve only top, then A is elected.  If the default
> is to approve all ranked candidates, then C is elected.
>
>
> Neither case rewards the buriers.
>
>
> If the 44 buriers were more conservative in their burial by not approving
> C …
>
>
> 43: A
>
> 03: A>B
>
> 44: B>>C  (sincere is B or B>A)
>
> 10: C
>
>
>
> … then A would win without regard to the convention of the default
> approval cutoff.
>
>
> So far so good!
>
>
> Forest
>
>
> P.S.
>
>
> Monkey Puzzle,
>
>
> I'll write a definition and brief explanation of MDDA(symmetric
> completion) and its relation to MDDTR, ICA, and ICT tomorrow.  It looks
> like I won't have enough time today.
>
>
> But briefly it is a cross between ICA and ICT, where the voters can decide
> where the approval cutoff is on their ballot.  If they put it just under
> Top, then their ballot is counted as in ICT.  If they put it just above
> Bottom, then their ballot is counted as in ICA.
>
>
> MDDTR(pt/2) and ICT are the same.
>
>
> Gotta go!
>
>
> Forest
>
>
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>
>
>
>
>
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