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

Thu Dec 8 15:35:30 PST 2016

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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