[EM] SARA voting: easier-to-describe MAS

Tue Oct 25 23:33:21 PDT 2016

MAM is fine for polls, especially if experience shows that voting is
sincere.

But official elections need FBC. Especially for current conditions, but in
general I consider it a basic requirement for official elections.

Michael Ossipoff

On Tue, Oct 25, 2016 at 11:35 PM, Michael Ossipoff <email9648742 at gmail.com>
wrote:

> Right.
>
> Condorcet tries for something ambitious, at the cost of something basic.
>
> Michael Ossipoff
>
>
>
> On Tue, Oct 25, 2016 at 10:48 PM, C.Benham <cbenham at adam.com.au> wrote:
>
>> You mean "disqualified"  like all other Condorcet  methods?
>>
>> Chris Benham
>>
>>
>>
>> On 10/26/2016 9:05 AM, Michael Ossipoff wrote:
>>
>> Oops! Smith//Approval is disqualified by its FBC failure
>>
>> Michael Ossipoff
>>
>> On Tue, Oct 25, 2016 at 2:55 PM, Michael Ossipoff <email9648742 at gmail.com
>> > wrote:
>>
>>> But MMPO's Weak CD remains as an advantage, because the chicken dilemma
>>> can be a nuisance in Approval.
>>>
>>> So MMPO isn't completely ruled out.
>>>
>>> Michael Ossipoff
>>> On Oct 25, 2016 9:40 AM, "C.Benham" <cbenham at adam.com.au> wrote:
>>>
>>>> On 10/25/2016 4:47 AM, Michael Ossipoff wrote:
>>>>
>>>> When sincerely-voted Approval chooses differently from Condorcet, it's
>>>> choosing socially better.
>>>>
>>>> (Jameson wrote):
>>>>
>>>> But even if they do win under honesty, they will probably lose under
>>>> "semi-honest offensive strategy" (SHOS) in which the stronger wing
>>>> truncates the CW to equal-bottom.
>>>>
>>>> (endquote)
>>>>
>>>> In rank methods, we've been calling that offensive truncation.
>>>>
>>>> In Approval, I don't regard it as an offensive strategy at all. In
>>>> Approval, the middle CWs doesn't need support from both sides, as s/he does
>>>> in general pairwise-count methods.
>>>>
>>>> The larger wing isn't the one that needs the CWs, if you're after the
>>>> best particular candidate you can get. But you're talking about a strategy
>>>> problem that shouldn't concern voters in Approval.
>>>>
>>>>
>>>> Mike,
>>>>
>>>> Given my selection of quotes above, I find your negativity on
>>>> Smith//Approval  (very similar to Max Covered Approval) a bit inconsistent.
>>>>
>>>> A couple of somewhat relevant questions:
>>>>
>>>> (1)How often is a sincere Condorcet winner who is supported by the
>>>> smallest of three factions of voters the Approval winner?
>>>>
>>>> (2) How often is the Approval winner not in the Smith set?
>>>>
>>>> And so what is wrong with Condorcet//Approval?
>>>>
>>>> Jameson:-In Condorcet systems, the CW wins under honesty by definition.
>>>> But under SHOS, any CD-compliant method gets the wrong answer.
>>>>
>>>> Mike: No. In wv, a CWs isn't vulnerable to truncation. S/he still wins.
>>>> ...the right answer in such a method.
>>>>
>>>>
>>>>  But Winning Votes isn't a "CD-compliant method" .
>>>>
>>>> Jameson wrote:
>>>>
>>>> Support Accept Reject Abstain voting works as follows:
>>>>
>>>>
>>>>    - Voters can support, accept, reject, or abstain on each candidate.
>>>>    Default is abstain.
>>>>    - Call a candidate "acceptable" if they are rejected by 50% or less
>>>>    and supported or accepted by over 25%. If any candidates are acceptable,
>>>>    eliminate all who aren't.
>>>>    - Give remaining candidates 2 points for each "support", 1 point
>>>>    for each "accept", and half a point for each "abstain". Highest points wins.
>>>>
>>>>
>>>> I still hate default being anything other than bottom/"reject", and the
>>>> "25%" figure looks arbitrary.
>>>>
>>>> With the default rule as it is, it looks like the method fails
>>>> Mono-add-Plump.
>>>>
>>>> Say the winner X has a lower point score than some other candidate Y
>>>> that is barely rejected by over 50%. Then adding some ballots that do
>>>> nothing
>>>> but "support" X could raise the 50% threshold enough so that now Y is
>>>> no longer eliminated and wins.
>>>>
>>>> Chris Benham
>>>>
>>>>
>>>>
>>>> On Oct 23, 2016 8:21 AM, "Jameson Quinn" <jameson.quinn at gmail.com>
>>>> wrote:
>>>> >
>>>> > Center squeeze occurs in 3-candidate election when the CW is the
>>>> plurality loser.
>>>>
>>>> So it refers to a special case of the problem of the defensive strategy
>>>> needed to protect the CWs's win.
>>>>
>>>> Certainly, in IRV, Benham, & Woodall, the main problem is when a middle
>>>> Cws has the smallest faction.
>>>>
>>>> And, in other pairwise-count methods, when I test for truncation or
>>>> burial vulnerability, I use such an example, because it seems more
>>>> favorable to finding vulnerability.
>>>>
>>>> But a CWs can lose without being smallest, and I don't make a
>>>> distinction about that except that it's part of the problem-examples in
>>>> IRV, Benham, and Woodall.
>>>>
>>>> You wrote:
>>>>
>>>> There are different levels of the problem, characterized by the level
>>>> of strategy necessary for the CW to win:
>>>>
>>>> (endquote)
>>>>
>>>> Sure. I was saying that with wv strategy, truncation from one side
>>>> can't take the win from the CWs. ...& that the CWs's voters can deter
>>>> burial by mere plumping.
>>>>
>>>> No need for the non-offensive wing to vote any less than sincerely in
>>>> methods with wv strategy.
>>>>
>>>> As you know, that isn't so with other Condorcet versions or general
>>>> pairwise-count methods.
>>>>
>>>> (You wrote):
>>>>
>>>> >
>>>> > -In systems like IRV or plurality, in order for the CW to win even
>>>> under honesty, the weaker of the two wings must betray their sincere
>>>> favorite.
>>>>
>>>> (endquote)
>>>>
>>>> Well, it isn't so much the size of the wing factions. It's more a
>>>> matter of which wing candidate is preferred by the CWs's voters.
>>>>
>>>> That's why I've been saying that IRV is fine for you if you're
>>>> majority-favored.
>>>>
>>>> If the CWs's voters transfer the other way, then you aren't in a
>>>> mutual-majority, and then, for you, IRV is then no better than Plurality.
>>>>
>>>> Many of us have been explaining that to Rob Richie for the past 30
>>>> years or so.
>>>>
>>>> > -In systems like approval and score, the CW may or may not win under
>>>> "honesty" (however defined). Arguably, if they do not, they should not.
>>>>
>>>> (endquote)
>>>>
>>>> Correct. When sincerely-voted Approval chooses differently from
>>>> Condorcet, it's choosing socially better.
>>>>
>>>> Sure, not choosing the CWs got IRV repealed in Burlington.
>>>>
>>>> Not electing the CWs results in a majority who'd prefer a different
>>>> result.
>>>>
>>>> But I think IRV was repealed for more than that:
>>>>
>>>> Approval let's people protect the CWs, without favorite-burial,  if
>>>> that were what they want to do.  ...and I suggest that it isn't, because
>>>> electing from your top-set is usually more important than electing the best
>>>> particular individual candidate you can.
>>>>
>>>> CWs protection is more for rank methods, which are about choosing
>>>> _among_ your top-set, to elect the best particular candidate you can.
>>>>
>>>> (But see my earlier post yesterday, about that.)
>>>>
>>>> If you have a top-set, then, by definition, electing from it is the
>>>> important thing.
>>>>
>>>> Approve (only) your top-set.
>>>>
>>>> (More about that in my post yesterday)
>>>>
>>>> But, if it turned out to be really important to avoid having a majority
>>>> who'd prefer a different result, then that  could be a reason for voters in
>>>> Approval to slightly modify their voting to avoid approving past the
>>>> expected CWs (CWse). ...though that would lower your Pt.
>>>>
>>>> When approving your top-set, you'd just stop short of approving past
>>>> the CWse.
>>>>
>>>> Yesterday, too, I spoke of the possibility of your wing-faction having
>>>> a social agreement to that effect.
>>>>
>>>> What you're saying doesn't contract what I've been saying.
>>>>
>>>> (You wrote):
>>>>
>>>> But even if they do win under honesty, they will probably lose under
>>>> "semi-honest offensive strategy" (SHOS) in which the stronger wing
>>>> truncates the CW to equal-bottom.
>>>>
>>>> (endquote)
>>>>
>>>> In rank methods, we've been calling that offensive truncation.
>>>>
>>>> In Approval, I don't regard it as an offensive strategy at all. In
>>>> Approval, the middle CWs doesn't need support from both sides, as s/he does
>>>> in general pairwise-count methods.
>>>>
>>>> The larger wing isn't the one that needs the CWs, if you're after the
>>>> best particular candidate you can get. But you're talking about a strategy
>>>> problem that shouldn't concern voters in Approval.
>>>>
>>>> (You wrote):
>>>>
>>>> The defensive strategies that work are for the weaker wing to give the
>>>> CW near-top score, and/or the CW faction to give the stronger wing
>>>> near-bottom score.
>>>>
>>>> (endquote)
>>>>
>>>> Both, if people are trying for the best candidate they can get. Then
>>>> obviously the smaller wing should support the CWs, and the CWs's voters
>>>> should plump.
>>>>
>>>> But I don't suggest that goal for Approval, for the reasons stated
>>>> above, & in earlier posts.
>>>>
>>>> > -In Condorcet systems, the CW wins under honesty by definition. But
>>>> under SHOS, any CD-compliant method gets the wrong answer.
>>>>
>>>> No. In wv, a CWs isn't vulnerable to truncation. S/he still wins.
>>>> ...the right answer in such a method.
>>>>
>>>> With burial, a potentially  successful buial can succeed or fail,
>>>> depending on whether the CWs's voters plump. Either way, the CWs doesn't
>>>> win.
>>>>
>>>> (You wrote):
>>>>
>>>> ; the strategy is effective if the CW faction plumps, and backfires if
>>>> the CW faction cooperates with the weaker wing. Note that even a strategy
>>>> backfire here is not in my opinion a "good" result; because the strategy
>>>> has some chance of winning, it will be sometimes attempted. Strategic
>>>> backfire is a good thing if it discourages the strategy, but a bad thing if
>>>> it actually occurs.
>>>>
>>>> Yes, that's what makes Condorcet at least a bit questionable.
>>>> ...especially with the possibility of the perpetual burial fiasco.
>>>>
>>>> But it can probably be argued that, with rank methods' goal of getting
>>>> the best individual candidate you can get, wv strategy improves on Bucklin,
>>>> because, even if people misjudge who the CWs is, and so hir voters don't
>>>> plump, the mere threat of plumping could be enough to deter burial, because
>>>> the would-be buriers don't have better information than the defenders have.
>>>>
>>>> > -In most basic Bucklin systems, the CW faction must defensively plump
>>>> to counteract SHOS.
>>>>
>>>> Yes, in Bucklin, if you aren't majority-favored, and if you rank
>>>> sincerely, and if the CWs's voters don't plump, then that can result in the
>>>> election of someone in your bottom-set.
>>>>
>>>> (You wrote):
>>>>
>>>> > -In a system like SARA, in most cases, even if the CW does not
>>>> defensively plump, the weaker wing can give enough support to the CW to
>>>> protect them from SHOS, without having to rate them equal-top. (If the CW
>>>> is only barely a CW, the weak wing may have to rate equal-top for a
>>>> successful defense in this case. However, I think that very
>>>> tightly-balanced situations like this are not a large concern.)
>>>>
>>>> (endquote)
>>>>
>>>> That makes me sit up & take notice, because such an improvement on
>>>> Bucklin strategy, while keeping FBC, would be major, & could outweigh the
>>>> lack of CD enough to compete with the best methods.
>>>>
>>>> Michael Ossipoff
>>>>
>>>>
>>>>
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