[EM] (6) To Kristofer and everyone: MJ best to ‘tolerate’
C.Benham
cbenham at adam.com.au
Fri Sep 16 21:42:20 PDT 2016
On 9/16/2016 4:22 AM, steve bosworth wrote:
> MJ simply asks each voter to grade each candidate when judged against
> each voter’s own criteria of what an EXCELLENT candidate would look
> like.Any candidate judged to be less than EXCELLENT must be graded
> either as VERRY GOOD, GOOD, ACCEPTABLE, POOR, or REJECTED.Balinski and
> Laraki refer to each voters own criteria for grading candidates as
> being ‘absolute’ (but this is only in the sense that these criteria
> should be independent of any one set of candidates that might be
> seeking election).
C: To begin with superficial aesthetics, the grades should have simple
neutral names (like A B C D E F) and the ballot "request" should be
something like:
"Give your favourite candidate or candidates an A and and your least
preferred candidate or candidates an F and any intermediate candidates
whatever
grade you see fit. Default rating is F."
As it is if in a given election A , by my "criteria that should be
independent of any one set of candidates that might be seeking election"
, such as those doing so in election A,
I rate my favourite candidate as being merely "Acceptable" I would
resent having to either (a) accept that my vote will have less
influence on the result than voters who rate
their favourite as "Excellent" or (b) "lie" and falsely indicate that I
rate my favourite as "Excellent".
MJ poses as being somewhat like a jury in a trial, or a panel that
judges say a competitive performance of Gymnastics or Diving.
But elections for powerful public political elections are very
different. In those cases the jurors/judges are more-or-less
"disinterested", i.e. it doesn't really make any
possible difference to their lives who wins the competition or whether
the accused is jailed or set free. In elections who wins the election
could have a big effect on the
lives of voters.
Also in those other cases there is usually general agreement what an
excellent sporting performance looks like and what a terrible sporting
performance looks like and
what constitutes clear proof of guilt or innocence. In elections voters
often have opposing ideologies, i.e. very different ideas of what
policies, priorities, political philosophy,
diplomatic/military strategies the election winner should have.
Another difference is that in those other cases the people on the jury
in a trial or the panel judging a sporting performance base their
decisions the same evidence. The jurors
all hear the same evidence and arguments and base their verdict on that.
Likewise the judging panel all closely watch the same performance and
give their scores based purely
on that.
But voters in public elections vary widely in terms of what information
they get, and the quality and quantity of that information. And of
course much of the "information" they
use might be false or misleading, generated by those with a big interest
in who wins the election.
Leaving aside the strategy incentive for voters to only use the very top
and very bottom grades, suppose that all the voters rate the candidates
as sincerely as they can
in the way MJ "invites" them to. Suppose that that there are only two
candidates with any hope of winning, A and B. Suppose I think that A is
clearly better than B
and you think the opposite. Suppose my rating of A is Good and B is
Poor, and your rating of B is Excellent and A is Rejected.
Your pairwise preference will have greater weight than mine. Is that
fair? According to the MJ philosophy your vote should have greater
weight because you are more
"enthusiastic" in your support for B over A. Does this greater
enthusiasm mean that your opinion that B is better than A is more likely
to be correct than my opposite
opinion?
> Also, MJ seems to offer less scope for manipulative voting than any
> other method.
C: As Kevin has pointed out, sincere voters are less likely to be at a
disadvantage than with Range (aka Average Ratings) but in both the
voter's best strategy is to only
use the two most extreme ratings. If all the voters do that the method
is just Approval.
What exactly is your definition of "manipulative"?
> I still favor MJ even though it is theoretically vulnerable to
> ‘Later-no-harm’ (LNH).
C: I don't particularly care about Later-no-Harm. It encourages the
expression of preferences that may be very weak, and to the extent that
they are decisive they
would tend to lower the "Social Utility" (SU) of the winner. And the
expressed preferences are also more likely to be the result of
unprincipled mutual back-scratching
deals between candidates.
I put a greater value on Later-no-Help (which MJ, along with MTA and
MCA meets). Ideally there should be weak zero-info truncation incentive.
But MJ has a very strong truncation incentive. It's compliance with
LNHelp is in practice useless if the voters should all truncate.
IRV meets both of Later-no-Help and Later-no-Harm, and in my opinion it
is the best of the methods that meet Later-no-Help.
Other methods I like fail both. That is better than only meeting LNHarm
and so having a random-fill incentive, or only meeting LNHelp and having
a very
strong truncation incentive.
For reasons I might give in another post, I don't much like MAM. A
simpler Condorcet method I like is Smith//Approval:
Voters ignore candidates they don't approve and rank the rest.
Equal-ranking allowed. Elect the most approved member of the Smith set.
The "Smith set" is the smallest set of candidate/s who all pairwise beat
all (if any) outside-the-set members. A single-member "Smith set" is the
Condorcet winner.
Compliance with both FBC and Condorcet is impossible. MJ meets FBC.
A MJ-like method that is simpler and in my view better is Majority Top
Approval (MTA).
It uses 3-slot ratings ballots. Default rating is Bottom. If any
candidate is rated above bottom on more than half the ballots, elect (if
there is more than one) the
one of those with the highest number of top ratings. Otherwise elect the
candidate with the highest number of above-bottom ratings.
The voters' best strategy is to normally use only the top and bottom
ratings slots, but the middle slot is handy if there is one or more
candidate the voter is
unsure how should rate on a 2-slot ratings ballot, or if the voter is
prepared to maybe take a small strategic risk for the sake of being more
expressive.
But a more complex method I much prefer is IBIFA.
http://wiki.electorama.com/wiki/IBIFA
Chris Benham
> ________________________________________
>
> From: Kristofer Munsterhjelm <km_elmet at t-online.de>
>
> Sent: Wednesday, June 1, 2016 9:14 PM
>
> To: steve bosworth; election-methods at lists.electorama.com
>
> Subject: Re: [EM](6) To Kristofer and everyone: MJ best to ‘tolerate’
>
> ___________________________________________
>
> To Kristofer and everyone:
>
> Kristofer, while our most recent exchange was on June 31^st , I want
> to thank you for forcing me to think more carefully and completely.As
> a result of the clarifications you offered me, when combined with my
> recent EM discussions with Kevin and Jameson, I am currently favoring
> MJ over all other methods for electing a president.
>
> MJ simply asks each voter to grade each candidate when judged against
> each voter’s own criteria of what an EXCELLENT candidate would look
> like.Any candidate judged to be less than EXCELLENT must be graded
> either as VERRY GOOD, GOOD, ACCEPTABLE, POOR, or REJECTED.Balinski and
> Laraki refer to each voters own criteria for grading candidates as
> being ‘absolute’ (but this is only in the sense that these criteria
> should be independent of any one set of candidates that might be
> seeking election).These criteria are not rankings but they can be used
> to make rankings.MJ’s winner is the candidate whose majority
> ‘median-grade’ is higher than any other candidate.
>
> For example, I see MJ as both better than IRV and MJ because:
>
> 1.
>
> I believe that ordinary citizens would more easily understand both
> how to mark MJ’s ballot and how the winner is discovered using its
> count.They would find it even more difficulty in understanding how
> MAM’s ballots are counted.
>
> 2.
>
> At the same time, both MJ and MAM have the following similar
> advantage over IRV:All MAM voters’ ‘rankings’ and MJ voters’
> ‘gradings’ of all candidates continue to count until their
> respective winners are discovered.Some of the IRV voters’
> ‘rankings’ are not counted after any of its candidates are
> eliminated and before IRV’s winner is discovered.
>
> 3.
>
> However, MJ has another advantage over MAM: because ‘grades’ are
> more evaluatively clear than are ‘ranks’, MJ’s ‘‘majorities of
> grades are … considerably more discerning decisions than are
> [MAM’s] majorities of preferences’ (Belinski & Laraki, Majority
> Judgment, p.283)?
>
> 4.
>
> Moreover, unlike the different intensities of each MJ voter’s
> ‘grades’ (evaluations) for each candidate, the different
> intensities of each MAM voter’s ‘rankings’ recorded on her ballot
> are not directly counted.For example, an MAM voter’s different
> intensities of preference for A over B and A over G in the
> following list of preferences are not differently
> counted:A>B>C>D>E>F>G.In contrast, all the ‘grades’ given to all
> candidates by all MJ voters continue fully to count until the
> highest ‘majority-grade’ winner is discovered. Thus, I see MJ as
> the most democratic method because it both wastes no citizen’s
> vote and is most likely to elect the candidate who is supported as
> enthusiastically as possible by the larges majority of citizens.
>
> 5.
>
> Also, MJ seems to offer less scope for manipulative voting than
> any other method.B&L argue that MJ is entirely strategy-proof with
> regard to grades.At the same time, if B&L’s mathematical proofs
> are correct, even when and if voters might instead use MJ’s
> ‘gradings’ as ‘rankings’, MJ structurally cuts by almost ‘half’all
> the opportunities for all the manipulative strategies that are
> offered by all the methods other than MJ (Belinski & Laraki,
> Majority Judgment, pp.14, 15, 189-198, 212, 245, 282-292). (I
> assume that your mathematical knowledge is currently much superior
> to mine.Consequently, I’m hoping that you will be able to tell me
> whether the above B&L claim of ‘almost half’ is fully justified by
> B&L’s mathematical proofs.)
>
> If it is fully justified, MJ would have this advantage over IRV
> and MAM.I say this even though it still seems to me that, in any
> case, it would also be extremely unlikely that strategic voting
> would be successful when using IRV or MAM to elect one winner by
> millions of voters.
>
> 6.
>
> I still favor MJ even though it is theoretically vulnerable to
> ‘Later-no-harm’ (LNH).I am currently persuaded by B&L that this
> could occur in practice only in an election composed of voters and
> candidates whose numbers could be counted on one person’s hands.
> This is confirmed by Jameson in his 1st informative and recent EM
> posts: 1): ‘there is the failure of the later-no-harm (LNH)
> criterion. But note: MJ actually does pass a weaker version of
> LNH: rating additional candidates at above bottom will not harm
> the winner as long as those candidates are ranked below the
> winning median. My claim is that over time, the winning median
> grade will mostly fall in a given band of grades; for instance,
> using letter grades, between B- and D+. In that case, making
> distinctions between A and B at the top or D and F at the bottom
> are strategically safe.’
>
> 7.
>
> Similarly, I am aware that MJ fails the strong Independence of
> Irrelevant Alternative (IIA) candidates test. However,B&L explain
> how MJ does at least pass a weaker IIA test.As Jameson put in his
> 2^nd recent and informative EM contribution: ‘Note that this
> strategy will almost certainly not affect the medians, and thus
> will not change the winner. Though technically it breaks IIA, it
> only does so in bizarre cases where both voter and candidate
> distributions differ severely from historical norms.’
>
> S: I would very much appreciate anyone explaining why you think any of
> the above views are mistaken.Please try to correct any mistakes you
> have noticed in the above.
>
> I look forward to hearing from you,
>
> Steve
>
>
>
>
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