[EM] Approval Voting and Long-term effects of voting systems

Michael Ossipoff email9648742 at gmail.com
Mon Dec 12 11:04:04 PST 2016


On Mon, Dec 12, 2016 at 12:52 AM, C.Benham <cbenham at adam.com.au> wrote:

> On 12/9/2016 10:05 AM, Michael Ossipoff wrote:
>
> The fact of it being better to equal-rank the set that is important to you
> instead of choosing among them is true with other rank methods too.
>
> In particular, it's true of Condorcet & Bucklin. It would be true of IRV
> too, if IRV allowed equal-ranking.
>
> I don't have proof that it's, in principle, a property of _all_
> ranking-methods, but I don't know of an exception.
>
>

Hi Chris--



>
> Mike,
>
> If  IRV allows equal-ranking, it should definitely be the "fractional"
> version (so that in every round each ballot gives a single vote or
> fractions of a vote
> that sum to 1).
>

The only reason why, some years ago, I suggested ER-IRV(whole) was because
I thought it met FBC. When Kevin pointed out that it doesn't, I no longer
have advocated that method.

Ordinary IRV, Benham & Woodall are fine, as-is.

I've discussed the fact that they have a problem, but that the problem has
mitigations. IRV's worst problem has been the dishonest promotion of it,
with false guarantees substituted for the disclosures and warning that it
needs.

IRV would be fine, if, before enacting it, people understood & accepted its
problem, and weren't going to favorite-bury,  or repeal it as soon as it
eliminates a CWv.

So, if, in some jurisdiction, IRV is the method that's popular as a
proposal, my message to its advocates would just be to promote it honestly,
and to not advocate or enact it unless they understand and accept how it
works, what it can do, its unique character & tradeoff.

Well, this is progressive partisanship, but one reason why i wouldn't want
IRV now is that it appears that, here, under current conditions, IRV's
problem, even if mitigated in general, would work against progressives if
it happened.
But I suspect that, with honest media, and well-informed voters, IRV's
problem's mitigations would make its problem a lot less important.

Benham & Woodall elect a CWv when there is one, and that's an improvement.
They're quite vulnerable to burial or truncation, but the worst that those
can accomplish is to give IRV results. IRV at worst, Condorcet at best.

But the trouble is that IRV has always been dishonestly promoted without
the necessary disclosure, which was why it was angrily repealed in
Burlington, by people rightfully angry about having been deceived by
promoters.
.
Also:  Though, with public ballot-imaging, _any_ voting-system is secure
against count-fraud, we don't currently have that (maybe never will) , and
any effort to catch or prevent count-fraud is doubtful, then it's important
to not make successful count-fraud any easier than it has to be.

That means not using a voting system that isn't precinct-summable. That's
the other big reason to not enact IRV or its derivatives, under current
conditions.

You wrote:

You wrote "I don't have proof that it's, in principle, a property of _all_
ranking-methods, but I don't know of an exception."

It's true of  Winning Votes and Bucklin and any of the proposed methods
that meet FBC, but I don't see how it is of  ER-IRV(fractional).

[endquote]

Maybe. I hadn't considered fractional IRV or Margins Condorcet when making
that statement. Admittedly I was only looking at a few kinds of methods,
and so my statement was too much of a sweeping-statement.

You wrote:

Or MinMax Margins or  ER-Benham(fractional)  or even  Smith//Approval
(implicit).

[endquote]

Smith//Approval?

What if there's member, X, of your strong top-set that is only in the voted
Smith-set because, if you equal-top-rank, it ties or beats a certain
member, Y, of the Smith set who is in your strong top-set.

But now you rank your strong top-set sincerely, and now Y beats X. Now X is
beaten by everyone in the voted Smith-set. X had been the winner, because
of its high approval-total, but now some other voted Smith-set winner, Z,
with next highest approval, wins, and Z is in your strong bottom-set.

So are you sure that equal-top-ranking all of your strong top-set isn't the
best strategy in Smith//Approval?

But I don't advocate Smith//Approval, because I feel that, if you're going
to use a ranking-method, it should meet FBC  & at least have a convenient
way to avoid chicken-dilemma.

(IRV is an exception, regarding FBC--Under the right conditions it could be
acceptable, but of course it should be selfishly opposed by people who'd be
on the wrong end of its problem).

You wrote:

In the latter case obviously the voter should truncate hir bottom-set, but
couldn't it be the case that if the voter strictly ranks hir top set then
one
of them will be the CW while the most approved candidate is in hir bottom
set but if the voter equal top-ranks hir top set there will be a top-cycle
that includes the most approved candidate?

[endquote]

True. Like all un-improved Condorcet methods, Smith//Approval fails FBC,
and equal top ranking your strong top-set could elect a member of your
strong bottom-set.

But isn't it true that the voter ordinarily wouldn't know which strong-set
member s/he should strategically rank over the others?  ...which strong
top-set member shouldn't be moved to top?


But that wouldn't usually be unpredictable, and so wouldn't it still be
best toequal-top-rank.one's whole strong top-set?

Michael Ossipoff

Chris Benham


On 12/9/2016 10:05 AM, Michael Ossipoff wrote:

>
>
> When I used the example of MDDA & MDDAsc, to illustrate that it's better
> to equal-top-rank your strong top-set, rather than choosing among them by
> ranking them in order of preference--That wasn't intended as criticism of
> MDDA & MDDAsc
>
> The fact of it being better to equal-rank the set that is important to you
> instead of choosing among them is true with other rank methods too.
>
> In particular, it's true of Condorcet & Bucklin. It would be true of IRV
> too, if IRV allowed equal-ranking.
>
> I don't have proof that it's, in principle, a property of _all_
> ranking-methods, but I don't know of an exception.
>
> One fairly obvious thing that can be said for MDDA & MDDAsc is that your
> protection for your strong top-set, even when ranking them (and no one
> else) in order of preference, and approving them all (as is the default),
> is as good as your protection of them in Approval, when you approve only
> lthem.
>
> A majority doing so in approval will elect one of them.
>
> A majority doing so in MDDA or MDDAsc will give a
> majority-disqualification to everyone else. And if preferrers of one of
> your strong bottom-set try burial or truncation, and if they thereby manage
> to make everyone majority-disqualified, then someone in your strong set
> will win the Approval count.
>
> That suggests that MDDA & MDDAsc let you choose among your strong top-set,
> and still protect them from your strong bottom-set just as well as Approval
> would have let you. That's an improvement over Approval.
>
> Of course an additional improvement is that MDDA & MDDAsc give you an
> easy, convenient, & reliable way to avoid chicken-dilemma (by denying
> approval to the candidate of the distrusted faction.
>
> It's just that MDDA & MDDAsc allow you to further enhance the protection
> of your strong top-set, by top-ranking them all. If a majority do that,then
> it would be quite impossible for buriers or truncators to
> majority-disqualify them. Of course if any significant number of voters
> similar to you top-rank those candidates, that makes it much more
> difficult, or impossible, for buriers or triuncators to majority-disqualify
> them.
>
> If you use the chicken-dilemma defense of denying approval to the
> candidate of the distrusted faction, and that candidate is someone whom you
> top-rank, then you're still protecting hir from burial & truncation, for
> the reason described above.
>
> If the candidate to whom you deny approval is someone you rank below top,
> then that is no longer true. If the method is MDDA, that candidate still
> has the full truncation-proofness protection that any ranked candidate has.
> If the method is MDDAsc, that is no longer guaranteed. But, if
> Mono-Add-Plump is necessary for public acceptance, then the cutting-loose
> of that middle-ranked candidate of the distrusted faction is a regrettable
> but justifiable action resulting from reasons that that faction has given
> you for defection-deterrence.
>
> Likewise, though MDDA protects your middle-ranked candidates from
> truncation by eachother's factions, that protection isn't essential,
> because reliably choosing _among_ your strong top-set isn't the important
> thing.
>
> In MDDAsc, you're still fully protecting your top-ranked candidates
> against everyone else, and you're still fully protecting all of your
> rannked & approved candidates against your unranked, unapproved candidates.
> That's what's important.
>
> MDDA & MDDAsc are the rank methods that best deliver the benefits that are
> available from ranking-methods.
>
> Now, to resum my reply:
>
>
>>
>> I like to remind people that, very often, "Good enough is better than
>> best."  That is, a voting system (or a candidate) that is "good enough" may
>> very likely better than one that is "best".
>>
>
> Exactly. Eecting one that is good enough is much more important than
> reducing the probability of doing so, by trying to choose among the ones
> that are good enough.
>
> [Replying farther down] :
>
>
>>
>>
>>> 1. In this country, for the 99%, a progressive government would be
>>> incomparably better than a Republocrat government (like we've had for a
>>> long time, and still have).
>>>
>>> If you don't believe it, look at some progressive party platforms
>>> (Greens, etc.), and compare them to the things that people are saying that
>>> they want, or that they want changed.
>>>
>>> So, for the 99%, _any_ progressive would support better policies
>>> than_any_ republocrat.
>>>
>>> That means that, for the 99%, there's a strong top-set and a strong
>>> bottom-set.
>>>
>>> ...And, when there is, Approval voting is really simple:
>>>
>>> Approve (only) all of your strong top-set.
>>>
>>> 2. Suppose we're talking about a better world, in a better future, in
>>> which the 99% don't have a bottom-set. Or suppose we're talking about some
>>> other country, or some entirely different non-political
>>> voting-situation.in which you don't have strong top & bottom sets.
>>>
>>> There are various ways that you could vote.
>>>
>>> a) If you wanted to, and if any reliable predictive information is
>>> available, then you could use it for tactical voting. (We're talking about
>>> voting in Approval).
>>>
>>> b) If not, you could, if you wanted to, try to estimate where, in the
>>> candidate lineuup, your merit-expectation is, and approve down to there, as
>>> an expectation-maximizing strategy. Depending on what is known or felt
>>> about the relation between the distributions of voters & candidates, you
>>> could approve down to the mean, the mid-range, or the median, of the
>>> candidates' merits.
>>>
>>> Of course the median & midrange would be easiest: The midrange is the
>>> point halfway between the worst & the best. But easiest of all is the
>>> median. You'd approve the best half of the candidates. That could be
>>> regarded as a rough estimate for the other two central-tendency measures,
>>> when they're difficult to estimate.
>>>
>>
>> "Approve about half" is a good enough, easy to remember guideline.  It
>> would seem to maximize your impact as well.
>>
>
> Yes, you're voting between the maximum number of candidate-pairs.
>
> [Replying farther down] :
>
>
>
>
>>
>>
>> Whether "about half" is good enough does depend where the frontrunners
>> are in each voter's ordering of candidates, but given that the frontrunners
>> are likely to be close to the median across all voters anyway, then they
>> will likely be positioned near the median of most voters' ordering.
>>
>>
>>
>>> c) But you needn't bother with a) or b).
>>>
>>> Even without strong top & bottom-sets, you can still take a guess about
>>> which set you'd like to elect instead of the other candidates.
>>>
>>>
>>> Maybe, though you don't have strong top & bottom sets, you have
>>> _ordinary_ top & bottom sets, meaning that the merit difference between the
>>> sets is greater (even if not incomparably greater) than the merit
>>> differences within those 2 sets.
>>> If so, you likely will feel like approving (only) all of your (ordinary)
>>> top-set.
>>>
>>> Or maybe even that isn't so, and you don't have any kind of top & bottom
>>> sets. Maybe the merit gradation is uniform, without any gaps or natural
>>> dividing-lines. What then?
>>>
>>> Well, then you don't know where to make your approval cutoff. You don't
>>> have an obvious way to choose which set you want to approve over the other.
>>>
>>> No problem! If you don't know which set approve, then it doesn't matter!
>>>
>>> Just approve as you feel like. Maybe just guess. Maybe flip a coin, or
>>> draw a number from a bag. Or have the candidates' names in a bag, and draw
>>> one to choose which one to approve down to. If you don't know which set you
>>> want to approve, then it doesn't matter which set you approve.
>>>
>>> Any such set that you choose by guessing will include the best, and
>>> won't include the worst, and will be within the range that you feel that
>>> the approval cutoff should be in. That's good enough! Don't worry about it.
>>>
>>> Another thing: If, by guessing or drawing from a bag, you make a choice
>>> of what set to approve, but, when you start to actually do so, you don't
>>> feel good about it, then don't do it.
>>>
>>> Maybe you'll say to yourself, "This is _disgusting_ !"   Then of course
>>> don't do it. Don't approve down that far. Go by your feelings.
>>>
>>> People who assume, as a starting premise, that it's necessary to get the
>>> best candidate possible are making things unnecessarily difficult for
>>> themselves. Even the more elaborate methods, the ranking-methods, do do
>>> that as reliabliably automcatically as their advocates sometimes seem to
>>> believe.
>>>
>>> By approving (only) your strong top-set, or your ordinary top-set, or
>>> (absent either of those) a set that is a good guess, within the range where
>>> you feel that the approval cutoff should be--By approving that set, you're
>>> maximizing the probability of electing from that set.
>>>
>>> And that's good enough.
>>>
>>> My message to those who complain that Approval doesn't automatically
>>> elect the best candidate that you can get is: You worry too much.
>>>
>>
>> I'm not so worried about electing the best.  I would worry about electing
>> a much worse candidate in a surprising upset.
>>
>
> Then, in Approval, approve all of your strong top-set.
>
>
>
>> Elections really ought to be much more boring, but not enough to put us
>> to sleep.
>>
>
> With honest elections and honest media, elections wouldn't be boring,
> because you'd be choosing among various versions of the very best. The
> choice among them, the discussion regarding their different approaches to
> the best policies and directions, would be anything but boring.
>
> What's boring is when the media keep claiming your choice is between two
> criminallyi-corrupt, bought candidates, and when people believe it.
>
> Michael Ossipoff
>
>
>
>
>>
>>
>>>
>>> Michael Ossipoff
>>>
>>
>> I'm still planning to reply to a couple of your earlier messages with a
>> couple more comments.
>>
>>
>> --
>> Daniel LaLiberte
>> daniel.laliberte at gmail.com
>>
>
>
>
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