[EM] Trying to have CD, protect strong top-set, and protect middle candidates too

[Michael Ossipoff]

For this method, MTRI, the procedural definition is more understandable
than the recursive definition (though the recursive definition's brevity
could be useful).

So this is what I understand MTRI's procedural definition to be:

1. Order the candidates by their top-count score, with higher scores at top.

2. Switch the lowest pair of adjacent candidates whose lower candidate
pair-beats the higher one.

Repeat till there are no more pairs to switch. The highest candidate in the
order at that time wins.

-----------------------------------------------

As a CD rank method, this method is a competitor of MDDTR. What are the
property differences between MTRI & MDDTR?

In particular, how does MTRI compare with MDDTR in regards to protection of
a CWs against truncation & burial?

Michael Ossipoff


On Thu, Nov 17, 2016 at 2:55 PM, Forest Simmons <fsimmons at pcc.edu> wrote:

> On Thu, Nov 17, 2016 at 10:54 AM, Michael Ossipoff <email9648742 at gmail.com
> > wrote:
>
>> But wouldn't Smith//Approval, with approval cutoffs in the rankings,
>> share MDDTR's burial-vullnerability?
>>
>> ...with, additionally, vulnerability to truncation, which MDDTR _doesn't_
>> have?
>>
>> And Smith//Approval trades MDDTR's FBC for Smith, which I consider an
>> unfavorable trade.
>>
>
> Perhaps make truncation the default approval cutoff, but let voters move
> it higher as an option:
>
> 45 C
> 30 A>B or A>>B
> 25 B
>
> Voting A>>B would be the chicken defense (where sincere is 25 B>A).
>
> Voting A>B would be the truncation defense (where sincere is 45 C>B).
>
> With this option, MDDA would be an FBC compliant method that is truncation
> and burial resistant as well as quasi CD compliant.
>
> Is there a way to modify MDDA to make it satisfy mono-add-plump?
>
> How about incorporating some form of power truncation.  When you plump X
> and reduce the majority victory of Y over Z to a sub-majority, it would
> revert to a majority if you counted the common truncation of Y and Z
> against each other as even half a point.
>
> Btw, in case you didn't see it, one of my new favorite non-FBC methods is
> Most Approved Immune(MAI):  Elect the most approved immune candidate.
>
> This means elect the most approved candidate X that is unbeaten pairwise
> by the candidate that would win (recursively) if the method were applied to
> the same ballot set with X disqualified or withdrawn.
>
> It is the simplest approval based rank method that confers immunity from
> second place complaints on its winners.
>
> It is quasi CD compliant if voters can specify their approval cutoffs
> above the truncation level when they want to.
>
> A top rank version of this method is fully CD compliant:
>
> Elect the Most Top Ranked Immune candidate. (MTRI)
>
> In other words elect the most top ranked candidate X that is unbeaten
> pairwise by the candidate that would win (recursively) if the method were
> applied to the same ballot set with X disqualified or withdrawn.
>
> Forest
>
>
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