[EM] FairVote comment on Burlington dumping IRV

[Jameson Quinn]

2013/7/3 Abd ul-Rahman Lomax <abd at lomaxdesign.com>

> At 12:31 AM 7/3/2013, Jameson Quinn wrote:
>
>> Abd, I noticed something. I don't want to jump to any conclusions, so I'm
>> asking you directly.
>>
>> 2013/7/3 Abd ul-Rahman Lomax <<mailto:abd at lomaxdesign.com>a**
>> bd at lomaxdesign.com <abd at lomaxdesign.com>>
>>
>> ... Bucklin ...
>>
>>
>>  You said "Bucklin", not "EMAV". So, two questions and a comment:
>>
>> Q1. Why did you change?
>>
>
> EMAV is not a known method, it's brand new, I just announced it, and this
> is a general post, not about details about the specific method.
>
>
I find it encouraging that you make a distinction between which methods
you'd mention on a "general" and a "details" post. My current push with MAV
is intended for "general" posts; I'm not trying to suppress "details"
discussion.


>
>  Q2. Is there anything that would convince you to switch to saying "MAV"?
>>
>
> Not in that context, not yet.


You gave a qualified response, when I wanted an unqualified one. What would
it take in some other context, or later? A million dollars? BR data showing
it's better than EMAV for some voter model? Survey data showing voters love
it?


>
>
>  Comment: To me, "Bucklin" is not a system, but a class of systems; at a
>> minimum, it would include all different Progressive-era systems which were
>> called "Bucklin" at the time, but to me, it includes all
>> descending-approval-threshold-**until-majority systems (including for
>> instance MJ, GMJ, MCA, and MAV.)
>>
>
> My comments were referring to the class of systems, but also specifically
> to Bucklin -- which primarily means those early systems -- and FairVote
> propaganda was about "Bucklin."
>
> Of course I'd love to promote EMAV, but promotion is not my primary goal.
>
> The subject post was written to review Richie's response to the Burlington
> debacle, and traditional Bucklin -- say, three-rank, mandatory single votes
> in first and second rank, almost exactly the same as some of the old
> implementations -- would have fixed the Burlington problem easily. That
> does *not* mean that this would be ideal.
>
> As to MAV, I'd support it if the "regression" were *necessary.* I don't
> see it as that, and the fallback to higher preferences clearly moves away
> from maximizing expressed utilities.
>

1. MAV's "regression" is no more artificial than original-Bucklin's
"inclusion". For instance, any Bucklin method could be described using
antiapproval-style bottom-up vote summing, in which case original-Bucklin
would be the one with a "regression" and MAV would be a straightforward
count.

2. By the same token, it's also no further from maximizing expressed
utilities than original-Bucklin.

3. The purpose of the MAV rule is that it is strategically relatively
"safe" to add a second-to-bottom rating. The only way it could cause
preferred candidate to lose is if it caused a multiple majority AND the
other candidate had more higher ratings. This is both an unlikely
circumstance, as it would mean that the other candidate's supporters were
being significantly less strategic than your faction; and, in the rare
cases where it does occur, acceptable from a utilitarian point of view, as
in this case it's probably the other candidate who's the utility maximizer.
It's also perfectly clear from an expressive point of view; that is, in the
rare cases where doing so was strategically suboptimal, it will be easy to
"read" the likely result of a repeated election with strategic voters on
all sides, and to choose whether that is preferable than the weak
cooperation.

>
> I understand that it was frustrating for you that I appeared to support
> MAV, for a short time, but I think that we were pandering to some shallow
> arguments, that we don't need to avoid the "chicken dilemma," and that
> using the range ratings adequately addresses the concern.
>

What evidence would convince you that you are wrong about the chicken
dilemma? It's fine if you ask for evidence that you think doesn't exist,
but if you think your argument is unfalsifiable by any possible evidence,
something is wrong.

>
> I.e.:
>
> original Bucklin: with a multiple majority, all at or above the found
> majority rating are collapsed to approval. Same with majority failure. The
> result is that a lower preference may count *the same* as a higher one.
> It's the "approval problem"
>
> MAV: under the multiple majority at a lower preference rule, the system
> ignores the lower preference votes, using only higher-level approval
> information. It does count the lower preference votes, but not to
> distinguish between those candidates. I haven't done so, but I could show
> some problem scenarios. It solves the "approval problem," but at the cost
> of apparent expressed utility.
>

Here's some exactly symmetrical arguments for MAV:

MAV: with a multiple majority against, all at or below the found majority
rating are collapsed to antiapproval. Same with majority failure. The
result is that a higher preference may count *the same* as a lower one.
It's the "approval problem"

Original Bucklin: under the multiple majority at a higher preference rule,
the system ignores the higher antipreference votes, using only lower-level
antiapproval information. It does count the higher antipreference votes,
but not to distinguish between those candidates. I haven't done so, but I
could show some problem scenarios. It solves the "approval problem," but at
the cost of apparent expressed utility.



> EMAV: The system uses all the votes in the two cases (multiple majority
> and majority failure.) Thus lower preference votes do count, but only at
> deprecated value. The difference between full preference and minimal
> approval is 1/2 vote. The difference between full prefeence and the
> below-approval rank that is above maximum opposition is 3/4 vote. So EMAV
> is intermediate to original Bucklin and MAV.
>

No. GMJ or MJ are intermediate. EMAV throws the Bucklin principle out the
window, which means that in many or most elections, even if you have
perfect knowledge of other voters, no non-extreme ballot is strategically
optimal. Thus, EMAV will encourage many more voters to exaggerate than in
other rated Bucklin systems, including MJ, GMJ, MAV, MCA, Original Bucklin,
Bucklin//Condorcet, etc. The quality of the ballot information, and its
usefulness for analysis (be it score, Condorcet, or other) will be lower.

Jameson
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