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

Wed Dec 7 19:18:06 PST 2016

Daniel--

You wrote:

>
> The popular assumption is that it's essential to try to elect the best
>> individual candidate that you can get. Contrary to popular belief, that's
>> only an assumption, an unsupported one.
>>
>
> I think it is reasonable to expect that everyone should try to elect the
> best candidate, but it is not reasonable to expect that everyone can be
> satisfied, and I don't think anyone has that assumption.
>

Sure, not everyone can be satisfied by the election-result.

But I wouldn't say that everyone should try to elect the best individual
candidate that they can get. What if trying to elect the best candidate
that you can get, choosing among your strong top-set, increases the
probability of electing from your strong bottom-set. Is that good?

By the definition of the strong top *& bottom sets, electing from the
strong top-set instead of from the strong bottom-set, is incomparably more
important than the matter of _which_ strong top-set candidate you elect.

Instead of electing a progressive candidate who is honest, and wants the
same improvements that you (& the rest of the 99%) want, you elect a
corrupt, bought sociopathic Republocrat?  Increase the probability of that
in order to choose among the progressives (instead of just supporting them
all, to make it more likely that one of them will win?

MDDA & MDDAsc protect your ranked & approved candidates as well as Approval
does, while also choosing among them (by influencing majority pairwise
defeats among them). So it seems you aren't losing anything in that regard
with MDDA & MDDAsc, compared to Approval.

But, when you're voting in MDDA or MDDAsc, you can improve Pt, the
probability of electing from your strong top-set (which we can assume are
your ranked & approved candidates): You can rank them all at top.

If you have a majority who prefer your strong top-set to the others, but
some voters similar you approve lower than you do, resulting in some of the
worse candidates having maybe more approvals than your strong top-set do,
the preferrers of those worse candidates couldduse truncation or burial to
make everyone majority beaten, and then win because of their higher
approval total.

But if you've ranked your entire top-set at top (and maybe a few similar
voters do), then you have the best chance of preventing the truncation or
burial to make everyone majority-beaten. If lots of people rank someone at
top, how can any smaller-than-majority group make them majority-beaten? You
& lots of other people aren't ranking anyone over that person.

So, by equal top-ranking all of your strong top-set, instead of ranking
them in order of preference, you're lowering the probability of electing
from your strong bottom-set.

So often that's the choice: Choose among your strong top-set instead of
maximally supporting them all, and you thereby increase the probability of
electing from your strong bottom-set.

> How much we care about trying to get the best candidate also depends on
> how critical it is that we get a half-way descent candidate.  When most of
> the candidates are reasonably good, and one of them is likely to win, then
> it doesn't matter much.
>

Of course. Then you don't have a winnable strong bottom-set.

You can try to maximize your expectation, among those all-good candidates,
in any of various ways.

> When there is a large range of quality and a freakishly high number of bad
> candidates, then we need to be concerned
>

...and that's how it is now.

> , but then the difference is also fairly clear, and Approval Voting will
> work very well in that case too.
>

That's when Approval voting is at its easiest. You definitely have a strong
bottom-set. Approve (only) all of your strong top-set.

More next time.

Michael Ossipoff

(all replies in this message are above this point)

>
> 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".
>
>
>
>> 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.
>
> 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.  Elections really ought to be
> much more boring, but not enough to put us to sleep.
>
>
>>
>> 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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