[EM] Agenda Based Banks

[Richard, the VoteFair guy]

On 8/3/2021 3:29 PM, Susan Simmons (or Forest?) wrote:
 > ...
 > Why are people still talking IRV (and its tweaks), STAR, MJ, etc?
 >
 > Now we have a method ABB simpler than any of these somewhat popular
 > proposals, and equal (in criteria compliances) to any of the
 > academically respectable methods like CSSD, Ranked Pairs, River, etc ...
 > and far superior to classical methods like Copeland, Borda, Bucklin,
 > MinMax, Kemeny-Young, etc.
 >
 > Why can't we get off dead center and start moving forward instead of
 > backwards?
 > ...
 > But what can we do about it?

Please start by describing the method on Electowiki.

Speaking personally I need to see it described in order to evaluate how 
easy or hard it is to understand -- from the perspective of voters.

The next step would be to convey it to voters.  But keep in mind that a 
simple-to-explain-in-words method can be difficult to understand by 
people who are moved by feelings rather than words.

 > We know why ... zeal without knowledge, and big egos among movers and
 > shakers.

Indeed zeal and money are behind:

* The FairVote organization

* STAR voting

* Center for Election Science

Ironically those of us who promote Condorcet methods don't have money 
behind us.  The money is behind methods that dismiss Condorcet methods.

Sigh, ...

Richard Fobes
The VoteFair guy


On 8/3/2021 3:29 PM, Susan Simmons wrote:
> Actually, in the burial example below, ABB performs strictly better than
> DMC because under DMC, the burial of C by A either rewards A with a win,
> or leaves intact A's sincere 2nd choice as winner ... a zero risk gambit.
>
> By way of contrast, if A's gambit fails under ABB, then A's least
> preferred, B, wins ... a big risk, because A's raising of B enough to
> introduce the necessary cycle might also be enough to move B to the
> necessary agenda level (if it was not already there).
>
> In summary, ABB has both the best burial resistance and the best chicken
> attack resistance of any agenda based Condorcet method that we know of
> (and we know of oodles!).
>
> It seems doubtful that any simpler, monotone, clone free, ISDA, burial
> and chicken resistant method exists ... except perhaps Asset Voting,
> which is too far ahead of its time (and our time ...first promoted only
> 150 years ago by Charles L Dodgson) even for Steven J Brams the great
> academic promoter of Approval, another simple method too far ahead of
> its time.
>
> Have I over-looked something?
>
> Why are people still talking IRV (and its tweaks), STAR, MJ, etc?
>
> Now we have a method ABB simpler than any of these somewhat popular
> proposals, and equal (in criteria compliances) to any of the
> academically respectable methods like CSSD, Ranked Pairs, River, etc ...
> and far superior to classical methods like Copeland, Borda, Bucklin,
> MinMax, Kemeny-Young, etc.
>
> Why can't we get off dead center and start moving forward instead of
> backwards?
>
> We know why ... zeal without knowledge, and big egos among movers and
> shakers.
>
> But what can we do about it?
>
> Sent from my MetroPCS 4G LTE Android Device
>
>
> -------- Mensaje original --------
> De: Susan Simmons <suzerainsimmons at outlook.com>
> Fecha: 3/8/21 12:08 p. m. (GMT-08:00)
> A: Kristofer Munsterhjelm <km_elmet at t-online.de>,
> election-methods at lists.electorama.com
> Asunto: Re: [EM] Agenda Based Banks
>
> Suppose that A has high approval or high first place support ....
> whatever is likely to put him at the good end of the agenda ... but
> knows that C has the broad & deep support necessary to be the sincere
> CW... in particular beating A pairwise.. and that there is some
> candidate B that A beats pairwise ... and the sincere preference order
> of the A faction is (mostly) A>C>B, (among these 3 major candidates)
>
> Then A (emboldened by his presumed favorable agenda standing) gets the
> bright idea of convincing his supporters to bury C under B to create an
> artificial Condorcet cycle A>B>C>A.
>
> Without this artificial cycle C would win no matter the agenda order ...
> but now A, at the top of the agenda has a good chance. In fact, the
> three members of this Smith set are the only possible winners under ISDA
> (Independence from Smith Dominated Alternatives).
>
> When Smith has only three candidates, some agenda based methods, like
> SPE and ABL always elect the cycle member with the best agenda
> position... in this case A.
>
> Another method DMC (Definite Majority Choice), elects the item in the
> worst agenda position that pairwise beats every item in a higher
> position ... which in this case is A if the agenda order of favor is (1)
> C<B<A, but is C if the order is (2) B<C<A.
>
> How about ABB?
>
> In case (1) C is the first bank deposit, and B is the last, hence the
> winner.
>
> In case (2) B is the first deposit and A is the last, hence winner.
>
> Both DMC and ABB make A's gambit somewhat risky, and if C's supporters
> take the standard CW precaution of truncating below C, then A's agenda
> status becomes least favorable of the three, in which case A loses by
> any reasonable agenda based method.
>
> How do DMC and ABB compare under Chicken attack?
>
> 49 B
> 26 C>A
> 25 A (sincere is A>B)
>
> Given implicit approval as the agenda setting criterion, A has the
> favored agenda spot, which makes A win under SPE and ABL.
>
> Candidate C has the worst agenda position, so the agenda order is C<B<A,
> which makes Chicken attacker A win under DMC.
>
> So our last hope is ABB. It comes through by electing B... fortunately
> NOT electing the most favored Banks agenda item!
>
> [When Smith is a triple, Banks = Smith]
>
> The very thing that turned me off about ABB years ago (when it was just
> TACC) made it impervious to Chicken!
>
> ABB (Agenda Based Banks) looks Better and Better Actually (BBA).
>
> ... Forest (sharing Sue's phone)
>
>
>
>
>
>
> Sent from my MetroPCS 4G LTE Android Device
> -------- Mensaje original --------
> De: Kristofer Munsterhjelm <km_elmet at t-online.de>
> Fecha: 2/8/21 2:13 p. m. (GMT-08:00)
> A: Susan Simmons <suzerainsimmons at outlook.com>,
> election-methods at lists.electorama.com
> Asunto: Re: [EM] Agenda Based Banks
>
> On 02.08.2021 21:31, Susan Simmons wrote:
>> It turns out that this method as it stands is not monotonic, but if you
>> omit the downward part, then the remaining simpler version is monotonic:
>>
>> First initialize a set named "TheBank" with the most promising agenda item.
>>
>> Then, as long as even one agenda item pairwise beats every member
>> ofTheBank, deposit the least promising of these into TheBank.
>>
>> Elect the final deposit.
>>
>> This simple Banks compliant method is a generalization of TACC (Total
>> Approval Chain Climbing).
>>
>> The only thing I don't like about it is that even when the most
>> promising agenda item is in the Banks set, as likely as not it will
>> elect a different member of that set. My tweak was designed to overcome
>> that "defect" while preserving Banks efficiency. But it's not worth the
>> loss of monotonicity.
>>
>> Furthermore, it may turn out that the supposed "defect" actually confers
>> burial resistance ... for example ...
>>
>> 45 A>B (sincere A>C)
>> 25 B>C
>> 30 C>A
>>
>> Ballot pairwise beat cycle: A>B>C>A
>>
>> Agenda: C<B<A
>> (based on implicit approval, for example)
>
> That feels like it's a general feature. Consider e.g. Benham with a
> preset ordering as an agenda method (remove the loser until there's a CW
> among the remaining candidates). Then raising W puts more candidates
> between W and the end of the list, which means that in the worst case,
> more candidates have to be eliminated before W wins.
>
> It seems like there's some kind of tension where, on the one hand, being
> ranked more highly should be advantageous (which it is if the pairwise
> preferences don't change, because it saves W from early elimination),
> but on the other hand, being ranked more highly with pairwise
> preferences changing has a higher chance of being detrimental (because
> more candidates have to be eliminated before W becomes a CW).
>
> -km
>
>
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