[EM] [CES #8843] Re: MAV on electowiki
Abd ul-Rahman Lomax
abd at lomaxdesign.com
Wed Jun 19 10:32:32 PDT 2013
I don't want to continue carping about the article because I'm not
ready to write one myself. So this is just how it occurs to me, quickly.
Link to the article itself:
At 07:48 AM 6/19/2013, Jameson Quinn wrote:
>Here's the current version of the article. Note the new paragraph on
>strategy at the bottom.
>
>Majority Approval Voting (MAV) is a modern,
><http://wiki.electorama.com/wiki/Evaluative>evaluative version of
><http://wiki.electorama.com/wiki/Bucklin_voting>Bucklin voting.
Note that Bucklin was *partially evaluative.* That is, in original
Bucklin, the first and second ranks were *exclusive*. Drop the third
rank from the ballot, it was purely a ranked system. The third rank
allowed multiple approvals. So the full ballot can be seen as an
approval ballot, and approval is an evaluative system. The approved
candidates are then categorized.
The system described as MAV currently defines *four* approved
categories. "F" is described as an explicit category, when that,
itself, creates problems.
> Voters rate each candidate into one of a predefined set of ratings
> or grades, such as the letter grades "A", "B", "C", "D", and "F".
> As with any Bucklin system, first the top-grade ("A") votes for
> each candidate are counted as approvals.
It should be completely explicit that multiple candidates may be
categories in all categories, i.e., this is Bucklin-ER, basically.
>If one or more candidate has a majority, then the highest majority wins.
Arrghh. That is ordinary Bucklin.
Rather, "If, at a stage of counting, one and only one candidate has
obtained a majority (having approval from more than half of the
voters), that candidate wins."
Majority must be specified or someone might think it is "majority of
the votes," and there will normally be more votes than voters in
systems like this.
At some point it must be specified how "rank overvotes" are handled.
There are possible ways:
1. Ballot is voided. We don't like that!
2. Vote for candidate is voided. Also that is not great.
3. Highest rating marked counts. (This may have been traditional
Bucklin. The instructions said "don't do it.")
4. Lowest rating marked counts.
5. Top and bottom ratings are averaged. (So a rating of A and B would
give a rating that could be called A- or B+. GPA contribution 3.5.)
I like the fifth option because it actually would allow voters to
give an intermediate rating, thus providing some additional range
resolution with no additional ballot complexity, but some cost in
canvassing. That additional cost would be small, because most voters
would not use it, most voters not needing it.
In amalgamation, then, as to rank, 3.5 would be added in after A but before B.
This would convert a Range 4 ballot to Range 8, with the penultimate
bottom rating being missing, unless the bottom rating is explicit.
>If not, votes at next grade down ("B") are added to each candidate's
>approval scores. If there are one or more candidates with a
>majority, the winner is whichever of those had more votes at higher
>grades (the previous stage). If there were no majorities, then the
>next grade down ("C") is added and the process repeats; and so on.
>
>Note that if this process continues without a majority until the
>last grade ("F") is added, no new rules are needed.
This is technically correct, because the lowest grade amalgamation
*must* show 100%. This assumes an F default, so marking of F is
*irrelevant* except as a confirmation. If Fs are amalgamated with
blanks not being treated as F, then F becomes a vote for the
bottom-rating candidate. We don't want to create that confusion for a
moment, even.
For simplicity, dump the F rating entirely. It is assumed, an
unexpressed default rank.
MAV as a method should not specifically depend on the number of
ratings. MAV outside of a runoff system is a plurality method (as are
all voting systems that can complete without an *explicit* approval
of a majority of voters. In treating a midrange vote ("C", 2/4) as an
approval, we have already stretched *slightly* beyond that. Taking
this down more deeply into D/F waters is pretending a majority that
doesn't exist.
I can see more complex amalgamation rules that could use the D
ratings. The simplest rule, attempted here, doesn't cut it.
> Since by that point all grades will have been counted, all
> candidate tallies will reach 100%.
In other words, amalgamating the F ratings is *useless*. This treats
F as if it were a majority, it's a multiple majority, so
*unconditionally* the previous ratings will be used and the F
amalgamation will be ignored. So why do we even count it?
Just to make the system seem uniform all the way down?
As I've mentioned, the system should exist in two forms: plurality
result, or runoff feeder (which, then, is also in two forms:
conditional runoff and unconditional runoff. Unconditional runoff may
be better handled with a different system, an explicitly multiwinner
one, which has not yet been examined in detail.)
> The process above then naturally elects the candidate with the
> most approvals at the higher grades (D or above); that is,
> whichever has the fewest F's.
And I would say, fewest disapprovals, and disapproval includes D and
F. It also includes blanks.
> This is the best way to resolve such an election using only the
> information on the given ballots.
"Best" is a red flag word when it has not been clearly defined. You'd
never be allowed to say "best" on Wikipedia, without that, and maybe
even with it. That's called a "peacock word."
Why would MAV be any "better" than Bucklin? From the information on
the ballots, the plurality winner in the majority-finding stage is
arguably the "best winner." No, we support MAV because of the effect
on strategic voting. If we have a Bucklin system with greater ballot
resolution, MAV backup may be unnecessary. If voters are more
informed, it may be unnecessary.
I am not satisfied that we have adequately examined the issues, to,
yet, proclaim MAV as the "best" system up from pure Approval.
This point should be clearly made, though: MAV is Bucklin, with an
exception only appearing in the handling of multiple majorities.
Those will tend to be rare, because, more common, we can expect in
some kinds of elections, will be majority failure.
How majority failure is handled is a classic problem. Robert's Rules'
recommendation to organizations: Don't Do It! *Never* elect with a
mere plurality. The version of IRV that they described *requires* a
true majority (and even then, they point out the center squeeze problem.)
The backup concept, treating multiple majorities as possibly
indicating over-rapid addition of approvals, is interesting, but
looking at this is causing me to warm to a graduated median
method.... plus pushing toward finer resolution, which will reduce
the number of multiple majorities. *None of this is going to be fully
satisfactory, because making a decision with a mere plurality is
intrinsically problematic.*
What I *don't* like with MAV is that a large majority can be ignored
vs a bare majority, based on the votes at the higher rating.
Graduated median amalgamation can balance this. But I have not seen a
detailed examination of this issue, and it's important. The MAV
backup may be just a bit *too* simple. There is an alternative, as
well, that would pick the candidate with the highest GPA. That would
consider *all* the ratings. It's theoretically superior, because it
would be Range. The D ratings would count.
Another approach would use pairwise comparison. We *do* have explicit
approvals of a majority, if the median vote is C or higher. So, then
the ballots would be recanvassed to see how the majority-approved
candidates fare against each other. The collapsed approvals are
separate again. This would make the method Condorcet-compliant, if
I'm correct. And that would be a plus. I'm on board the concept that
the Condorcet criterion is not absolute, because of social utility,
but without explicit majority confirmation, I dislike finding
*against* the preference of a majority.
> However, in this and other cases of multiple majorities, a runoff,
> if feasible, would be a better way to ensure a clean majority win.
It's a *way*. Not simply a "better" one. The alternative presented
here is *not* a way to "ensure a clean majority win."
>This system was promoted and named due to the confusing array of
>Bucklin and Median proposals.
Premature. It has not been promoted. It has been *tentatively* named.
This, by the way, would be in a History section of an article, and it
only begins to tell the history.
> It is intended to be a relatively generic, simple Bucklin option
> with good resistance to the
> <http://wiki.electorama.com/wiki/Chicken_dilemma>chicken dilemma.
> It was named by a
> <http://lists.electorama.com/pipermail/election-methods-electorama.com/2013-June/031938.html>poll
> on the electorama mailing list in June 2013.
Geez, *recentism* to the 9s.
You know what I think about the "chicken dilemma." (Voting is not a
game of chicken, and "dilemma" is merely an ordinary problem in
strategy, which only afflicts a small segment of the population, the
rest will simply *vote.*) What MAV will do is to, I expect, *slightly
increase* the number of additional approvals, because they become
*safer*, i.e., less likely to cause the loss of the favorite to the
lower ranked candidate.
I prefer, Jameson, that the issue of the exact definition of MAV be
*left open* for the time being. Let "Majority Approval Voting"
actually be Supermajority Approval Voting," i.e, ultimately approved
by a supermajority of voting systems activists.
Not as the "ideal voting system," which it is not, but as the "ideal
next step beyond ordinary Approval, in a plurality context." It
introduces a ranked/rated ballot. It's simple to amalgamate and
understand. In most elections, the "tiebreaker" procedure is not
activated. Indeed, in most elections under some fairly common
conditions, there will be majority *failure*, not the multiple
majorities that the backup procedure handles.
>The grades or ranks for this system could be numbers instead of
>letter grades. Terms such as "graded MAV" or "rated MAV" can be used
>to distinguish these possibilities if necessary. In either case,
>descriptive labels for the ratings or grades are recommended. For
>instance, for the letter grades:
> * A: Unconditional support
> * B: Support if there are no other majorities above "C"
> * C: Support if there are no other majorities above "D"
> * D: Oppose unless there are no other majorities at all.
> * F: Unconditional opposition.
This treats D as an approval, so it divides the approved categories
into four rather than the three from Bucklin. We will need,
ultimately, a single, coherent, simple system to propose and try.
Notice that the definitions treat not-oppose as support. In my
analysis of the traditional Bucklin ballot, it's clear that the 3rd
rank was *minimum approval.* The ordinary meaning of a grade of "D"
is a kind of failure.
This is a *really complicated* explanation of the rating levels.
>As the above labels indicate, support at the middle grades or
>ratings is not partial, as in
><http://wiki.electorama.com/wiki/Score_voting>Score voting, but conditional.
That is correct. If the method terminates above the rating, it is not
used. That, by the way, is a flaw, from a social utility point of
view. I don't like that voters may be casting votes that are not
counted. I'm starting to think toward lines of using range
amalgamation in the "tiebreaker." And of suggesting that all votes be
counted, even if only for reporting. Incubator effect.
> That is, the typical ballot will still count fully for or against
> a given candidate.
Yeah. But I want to see a much more detailed analysis of this.
>The different grade levels are a way to help the voting system
>figure out how far to extend that support so that some candidate
>gets a majority.
Uh, really? It's more like "so that majority support is found if
possible from the votes." And a D vote is *not* "support." It might
be a weak stand-aside. "Okay, if the rest of you insist, this one is
better than that one." A strong stand-aside would be a C vote. In
consider C as neutral, as to preference strength. So-so. Not good,
not bad. "Passing," but barely. No honors. But ... might be serviceable.
>For a strategic voter, the most important ratings are the top ("A"),
>second-to-bottom ("D"), and bottom ("F").
"Most important" is, again, Peacock. Here, Jameson, you are giving
your own analysis, not the community's analysis. This is not a signed
article, even if your name is in the History. If you want to present
your own analysis, *attribute it.* Or attribute analysis to others. I
suggest not presenting your own opinions as if they were fact.
Sometimes in writing Wikipedia articles, I'd use "weasel words." This
is weak language, like, "Some say that ...." or "It could be claimed
that ...." or "According to some sources, ...." I really only did
that to find quick consensus, not to propose weasel language as
stable or desirable. It was typically replacing *strong language*
that did not actually reflect consensus.
>A typical zero-knowledge strategy would be to give the best 30% of
>candidates an "A", the next 25% a "D", and the bottom 45% an "F".
"Typical" according to what standard? What population? I would *not*
think this way *at all.* I would cast a Range ballot, period, using
the same strategy, i.e., considering what I know of the preferences
of others. With Bucklin, I can vote sincerely for my favorite under
almost all conditions, and the loss of voting power is miniscule. If
it's a zero-knowledge situation, I'd vote simple, normalized Range.
I'm really not worried about the multiple majority problem. My votes
will represent *true preference strength*. That only shifts with
knowledge of the electorate, where I will then vote Von Neumann -
Morgenstern utilities. I.e., to put it simply, which will powerfully
choose between realistic possibilities, reserving *some voting power*
for the expression of true preference, which is an independent value.
(And where partisan elections are involved, that has a long-term
effect. I am not just concerned about the *present election.*)
Some voting systems activists seem to think that voters are obsessed
with "winning," but that all that "winning" means to them is getting
their favorite elected. No, many voters consider it a "win" if the
winner has broad support, *even if they were personally opposed.*
>If the typical "honest" voter roughly calibrates their grades to an
>academic curve, with a median vote at "B" or "C", then strategic and
>honest votes will mesh well.
Perhaps. All this is vague, ungrounded argument. We don't have the
simulations yet.
>For instance, if candidates can differ on two dimensions, ideology
>and quality, and voters are normally distributed along the one
>dimension of ideology (with all voters preferring highest quality),
>then this system will tend to elect the candidate preferred by the
>median voter, that is, the one with the smallest sum of quality
>deficit plus ideological skew; and this tendency will hold for any
>unbiased combination of "honest" and "strategic" voters as defined above.
Jameson, you are presenting as if it were fact, your "back of the
envelope" conclusions. Please don't do that!
>The assertions in the strategic paragraph are based on some
>back-of-the-envelope diagrams; that is, I consider them likely to be
>true, but I have not run simulations to prove them. I think it would
>be interesting to do so. Would others be as interested as I would in
>such results; that is,
"In the opinion of Jameson Quinn ...."
Or, "As shown in a poll conduced by the Center for Election Science....."
>1. Finding an equilibrium zero-knowledge strategy (percentile-grade
>correspondence) in impartial culture. (I think this would be an
>exciting new direction for simulation research.)
I want to see Bucklin applied again, because the ballots will be
collecting Range data, not only for its value as a voting system.
The true revolutionary system is Asset, of course. It sweeps all
these concerns aside, makes them moot.
>2. Finding how broad the strategic conditions are (testing different
>"honest" grade distributions, unbiased strat/hon mixes, and
>strategic biases) in which MAV elects the median voter's favorite in
>the 2D/1D model sketched above? If my intuition is right, this model
>(unlike sparse or impartial models as criticized by Regenwetter)
>will allow good systems to show near-optimal BR; so MAV and Score
>will be have nearly the same (and nearly 0) honest BR, and the
>differences will be in that BR's robustness to different strategic profiles.
I'm suspecting that a different tiebreaker rule can do better. A
Range rule would *explicitly* maximize BR, as to what was expressed.
Runoff systems, of course, are known to take us beyond single-ballot
Range as to BR optimization with realistic votes.
>Jameson
>
>2013/6/18 Jameson Quinn
><<mailto:jameson.quinn at gmail.com>jameson.quinn at gmail.com>
>I've reworked the description. See what you think.
>
>
>2013/6/18 Abd ul-Rahman Lomax
><<mailto:abd at lomaxdesign.com>abd at lomaxdesign.com>
>At 04:25 PM 6/18/2013, Juho Laatu wrote:
>I quickly read the article. Here are some observations.
>
>- Term "Bucklin system" has not been defined. I can guess that it
>probably refers to Bucklin style stepwise addition of new approvals,
>but that may not be as obvious to all readers. If there is no
>definition of "Bucklin system", maybe one could say "As in Bucklin"
>instead of "As with any Bucklin system".
>
>
>There is a link to Bucklin voting in the article.
>
>
>- Sentence "if there are more than one with a majority, the "B"
>votes are removed and the highest sub-majority wins" is ambigious in
>the sense that it is not clear if "highest sub-majority" refers to
>all candidates or to candidates that had majority after adding the "B" votes.
>
>
>It's poorly worded, all right. Minor point: "There are more than
>one" grates. (I find the use of the singular or plural with "more"
>to be ambiguous. I'd avoid it.)
>
>An example is given when the principle has not been stated.
>
>The method does not make sense as stated. The "back-up" is a
>tie-breaker, considering multiple majorities as if they were ties.
>They *are* ties in median vote. The tie-breaker only selects a
>member of the tied set.
>
>Something went south. What was proposed was a Bucklin system.
>Bucklin does use, I've suggested, a range ballot, but the way that
>it does this is with a ranked structure. I ran into this when trying
>to design a set of votes to show a problem that I have not seen examined.
>
>The description on the wiki page makes the system seem more complex
>than it is.
>
>It's been designed to be five-rank, with explicit F. That's a fish
>bicycle. "No support" means merely "no support." No vote.
>Introducing the D vote is a later possible reform, it is an
>unapproved category. It makes the ballot considerably more complex,
>and the explanation is more complex.
>
>*D: Oppose unless there are no other majorities at all.
>
>
>Is that clear? I don't think so. Bucklin as Approval Voting doesn't
>have a "disapproved rank." All blanks are disapproved.
>
>
>- It is not quite clear what happens and if it is possible that
>there is no majority after the "F" votes have been counted.
>
>
>The F votes are never counted, first of all. Listing them is a
>mistake. (If the F votes continued the amalgamation, then someone
>would be voting *for* a candidate rated F. That was the intention
>for the D rating.
>
>It is far better, however, to introduce a D rating in combination
>with a runoff system, where the D rating could improve runoff
>candidate selection.
>
>When a voter rates a candidate as "D", they are opposing the
>election of that candidate.
>
>The Bucklin system required amalgamating three ranks. It's looking
>like MAV requires five, but that could be reduced to four, but the
>whole idea here was to have a *simple* next step beyond basic
>Approval Voting, and, as well, a clear similar method for use in a
>runoff system.
>
>(We basically need a step up from approval as a plurality method,
>and from approval as a primary method in a runoff system.)
>
>
>- The grades could be letters or numbers, but they could also be
>e.g. columns without any letter or number. This part of text
>discusses what the ballots might look like. I'm not sure if ballot
>different ballot formats should be seen as an essential part of the
>method definition, or if the method should be defined abstractly
>without referring to what the actual ballots might look like. I tend
>to define the methods abstractly without assuming anything on the
>ballots, and then discuss possible ballot formats as a separate
>topic, but I'm not saying that's the only and best approach. The
>current text is thus ok. I just first read the grades of the
>definition as abstract grades, not as definitions on what would be
>written in the ballots.
>
>
>*Something* should be on the ballot that expresses the *function* of
>a vote. Jameson took this concept from me. A voter should be able to
>see the ballot and have a reasonably clear idea, just from it, what
>the vote *means* ... and the meaning is the *effect* that the vote causes.
>
>The original Bucklin ballot, however, simply instructed voters to
>mark "1st choice," "2nd choice," or '3rd choice." The googlebooks
>copy is unclear,
><http://books.google.com/books?id=QcIqAAAAYAAJ&pg=RA1-PA757&dq=The+Grand+Junction+plan+of+city+government+and+its+results&hl=en&ei=uOTdS7aFKMKclgfq9739Cg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CDsQ6AEwAg#v=onepage&q=The%20Grand%20Junction%20plan%20of%20city%20government%20and%20its%20results&f=false>http://books.google.com/books?id=QcIqAAAAYAAJ&pg=RA1-PA757&dq=The+Grand+Junction+plan+of+city+government+and+its+results&hl=en&ei=uOTdS7aFKMKclgfq9739Cg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CDsQ6AEwAg#v=onepage&q=The%20Grand%20Junction%20plan%20of%20city%20government%20and%20its%20results&f=false
>
>Page 95. It looks like they actually instructed people to vote for
>all but one. But that part is quite unclear. In the first set of
>instructions, at the top of the ballot, they did suggest not voting
>for one candidate. There may be another copy of this ballot
>somewhere. Bucklin was widely covered.
>
>MAV *assumes that voters err if they approve two candidates by a
>majority.* That's why it backs up. But what, indeed, if it backs up
>and the multiple majority candidates are not the plurality winner in
>the previous round? What if there are *no* votes for those
>candidates in that round, or the vote is small.
>
>
>It said: "
>
>
>- The linked definition of "evaluatve" says that ranked systems can
>not give same ratings to two candidates. I think that's confusing and wrong.
>
>Juho
>
>
>Well, that's a common assumption of "ranked systems." It's
>essentially a definition, which is why we have said that Bucklin is
>*not* a ranked system. But, really, it's a ranked system that allows
>equal ranking. (Original Bucklin allowed equal ranking in the third
>rank only. We have simple expanded the approval principle to all
>ranks. *That is a convenience to voters.*)
>
>
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>
>
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