[EM] Anti-defection strategy device for IBIFA

[Michael Ossipoff]

Sure:

3-Slot Conditional Bucklin:

The ballot allows voters 3 rank positions in which to rank candidates.

The voter can use (rank someone at) as many or as few rank positions as
s/he wants to, but may not skip a rank and then use a rank below the
skipped rank.

A voter can rank any number of candidates at any of the 3 rank positions
that s/he uses.

The bottom, rank 3, is the default.

Additionallly, the ballot has a favorite-designation place, in which the
voter indicates hir favorite. (Or, if preferred, the rules could let the
voter indicate more than one favorite).
----------------------------------------------------------------------------
First, a description of the Bucklin count. Then the conditional-vote option
will be described.
----------------------------------------------------------------------------
Bucklin is just stepwise Approval, in which the Approval votes are given
one at a time, instead of all at once (and, as they're given we check for
any candidate acquiring a majority).

The Bucklin count consists of several rounds. In each successive round,
each ballot gives a vote to each candidate in the rank position where it
hasn't yet given votes.

In other words, in the 1st round, each ballot gives a vote to the
candidate(s) in its 1st rank position.

And in the 2nd round, each ballot gives a vote to the candidate in its 2nd
rank position.

...etc.

If, in any round, one or more candidates acquire a vote total greater than
half of the number of voters, the one with the highest vote-total wins.

If, after each ballot has given to all of it candidates, no one has a
majority, then the winner is the candidate who has the highest vote total
at that time.

Because this is 3-Slot Bucklin, there are 3 rank positions, and voters can
rank as many candidates as they want at any rank position (But of course
you can only rank a particular candidate at one rank position.).
-----------------------------------------------------------------------------------

The conditional-vote option:

A voter can designate any vote, to any candidate, at any rank-position, as
"conditional".


On any particular ballot, a conditional vote in the 1st round is given only
if the vote-receiving candidate is designated as "favorite" by more voters
than the candidate who is designated favorite on that ballot.

(If voters are allowed to designate more than one favorite, then for any
particular ballot, the conditional vote is given only if the vote-receiving
candidate is designated favorite on more ballots than is any of the
candidates designated as favorite on that ballot.)

In subsequent rounds, after the 1st round, a conditional vote is given b a
ballot only if the vote-receiving candidate has a higher vote-total (just
before that round) than any candidate who is designated favorite on that
ballot.

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

[end of method description]

People don't like complicated method-definitions. I'd probably save
conditional votes for a later refinement, and offer only ordinary,
non-conditional Bucklin first.

But Conditional Approval would be simpler and could maybe be offered as a
1st reform.

Michael Ossipoff








On Fri, Nov 4, 2016 at 11:27 AM, Jameson Quinn <jameson.quinn at gmail.com>
wrote:

> Could you state Conditional 3-slot Bucklin as you would define it for
> somebody who didn't know what "Bucklin" was?
>
> 2016-11-04 11:15 GMT-04:00 Michael Ossipoff <email9648742 at gmail.com>:
>
>> I'd said that, like 3-Slot ICT, Conditional Bucklin doesn't let you give
>> full protection to the distrusted voters candidate, or to any candidate
>> that you merely approve, because you aren't helping hir get a majority.
>>
>> But then, in a later posting, i said that the favorite-designation
>> shouldn't give anything in the points-count, because that would create a
>> strategic need to give that favorite designation to a compromise, or to the
>> distrusted voters' candidate.
>>
>> So the favorite designation would be distinct from the ratings that give
>> points, such as an Approval ballot, or the 1st rank of a Bucklin ballot.
>>
>> Well, my 2nd comment fixes the problem that I mentioned in my 1st comment.
>>
>> Have a favorite-designation that doesn't count for points in any way, and
>> whose only use is for determining whether the conditional approval should
>> be given.
>>
>> Below that is the Approval ballot, or the Bucklin ballot, starting with
>> its 1st rank position.
>>
>> Then, the method is Conditional Approval, or Conditional Bucklin, with a
>> favorite-designation used only for determining whether the conditional
>> approval will be given.
>>
>> In Conditional Buckllin,  every vote given by a ballot, at every stage of
>> the count (or every vote other than the the one given in the 1st round),
>> can be conditional, if the voter so marks it.
>>
>> A special case of that would be 3-Slot Conditional Bucklin, in which, in
>> addition to the favorite-designation, the ballot has a 3-Slot Bucklin ballot
>>
>> As I said last night, at any particular round of Conditional Bucklin, the
>> conditional vote would be given if the vote-receiver's vote total, just
>> before that round is greater than that of the giving ballot's designated
>> favorite with the highest vote total at that time.
>>
>> But maybe it would be better to only allow a ballot to designate one
>> favorite, partly to simplify the count rule, shortening the definition,
>> making it easier to propose.
>>
>> So: Conditional Approval, or Conditional Bucklin--which would include
>> Conditional 3-Slot Bucklin.
>>
>> As I said, no doubt Chris's improved interpretation of majority is indeed
>> an improvement, but it's too complicated for a first reform from Plurality.
>> It would be a good refinement for later.
>>
>> When there are two or more candidates getting a majority in a round, or
>> when there are no majorities at the end of the count, I prefer declaring
>> the winner based on vote-total, rather than top-count.
>>
>> For one thing it results in a briefer definition.
>>
>> And it makes the votes given at the various non-top stages of the count
>> more effective, which seems more in keeping with Bucklin's purpose..
>>
>> And it chose D in Forest's example that I was discussing last week.
>>
>> I understand that using the top-count instead of the vote-total helps the
>> chicken dilemma situation some, but it doesn't eliminate the chicken
>> dilemma..That's especially ok if the chicken dilemma problem is eliminated
>> by Chris's conditional vote option.
>>
>> Michael Ossipoff
>>
>>
>> On Thu, Nov 3, 2016 at 8:53 AM, C.Benham <cbenham at adam.com.au> wrote:
>>
>>> I normally don't like explicit strategy devices, and (beyond considering
>>> it desirable to elect from the
>>> voted Smith set) don't care very much about the "center squeeze" effect.
>>>
>>> (I like truncation resistance, so I'm happy with some of the methods
>>> that meet the Chicken Dilemma criterion.)
>>>
>>> Nonetheless here is  version of  IBIFA with a device aimed at addressing
>>> the Chicken Dilemma scenario.
>>>
>>> * Voters mark each candidate as one of  Top-Rated, Approved,
>>> Conditionally Approved, Bottom-Rated. Default is Bottom-Rated.
>>>
>>> A candidate marked "Conditionally Approved" on a ballot is approved if
>>> hir Top Ratings score is higher than the highest
>>> Top Ratings score of any candidate that is Top-Rated on that ballot.
>>>
>>> Based on the thus modified ballots, elect the 3-slot IBIFA winner.*
>>>
>>> ("Top-Rated"  could be called 'Most Preferred' and "Bottom-Rated" could
>>> be called 'Unapproved' or 'Rejected').
>>>
>>> To refresh memories, IBIFA stands for "Irrelevant-Ballot Independent
>>> Fall-back Approval", and the 3-slot version goes thus:
>>>
>>> *Voters rate candidates as one of  Top, Middle or Bottom. Default is
>>> Bottom.  Top and Middle is interpreted as approval.
>>>
>>> If any candidate X  is rated Top on more ballots than any non-X is
>>> approved on ballots that don't top-rate X, then the X
>>> with the highest Top-Ratings score wins.
>>>
>>> Otherwise the most approved candidate wins.*
>>>
>>> http://wiki.electorama.com/wiki/IBIFA
>>>
>>> 35: C
>>> 33: A>B
>>> 32: B (sincere might be B>A)
>>>
>>> In the scenario addressed by the Chicken Dilemma criterion, if all  (and
>>> sometimes less than all) of A's supporters only "conditionally"
>>> approve B then the method meets the CD criterion.  Otherwise it meets
>>> the Minimal Defense criterion.
>>>
>>> http://wiki.electorama.com/wiki/Chicken_Dilemma_Criterion
>>>
>>> http://wiki.electorama.com/wiki/Minimal_Defense_criterion
>>>
>>> Of course it meets the Plurality criterion and doesn't have any
>>> random-fill incentive.
>>>
>>> The downside is that the use of  Conditional Approval can cause a
>>> vulnerability to Push-over strategy.
>>>
>>> 48: C
>>> 27: B
>>> 25: A>>B
>>>
>>> The A supporters are all only conditionally approving B, but that has
>>> the same effect as normal approval because B has a higher Top Ratings score
>>> than A.  But now if 3 to 22 of the C voters change to C=A  then A's  Top
>>> Ratings score rises above B's so the "conditional" approval is switched off
>>> and then C wins.
>>>
>>> I dislike this "at the same time"-no-help failure, but the new result
>>> doesn't look terrible and of course if the B voters really prefer A to C
>>> then
>>> they were foolish not to conditionally approve A. If they'd done that
>>> then the attempted Push-over would have just elected A.
>>>
>>> (It crossed my mind to try to make Push-over strategising  more
>>> difficult and riskier with the same mechanism I suggested a while ago for
>>> IRV
>>> or Benham that allows above-bottom equal-ranking, but that would have
>>> broken compliance with FBC.)
>>>
>>> Chris Benham
>>>
>>>
>>
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>
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