Voting system R&D (Re: 2017 update to the SPI voting algorithm for Board elections)

Ian Jackson ijackson at chiark.greenend.org.uk
Thu Mar 2 19:18:06 UTC 2017


Barak A. Pearlmutter writes ("Re: Voting system R&D (Re: 2017 update to the SPI voting algorithm for Board elections)"):
> Ian and Joshua are dismissing these concerns, but have not given any
> technical grounds, either now or in the previous round of discussion.

I'm sorry that you feel that my many long messages in our private
email discussion in August did not contain "any technical grounds".
If that's what you think then you are unlikely to be satisfied by
anything I might say.

For the benefit of others I will go over the well-trodden ground
again.  (I will try to refrain from doing so more than once...)


You are advocating range voting.  I remain convinced that range voting
is a terrible voting system, because all but the most tactically aware
voters will cast hopelessly ineffective ballots.  This criticism
applies less to approval voting, but approval voting still involves a
lot of guesswork for voters.  Many people will cast ineffective
approval ballots.


But the key point, as discussed, is that SPI is poorly equipped to
analyse voting systems.  SPI is full of technologists.  We largely
lack political scientists, electoral officials, constitutional
engineers, and historians; we're probably even short of game
theoreticians.

(I have observed that technologists, particularly some computer
people, have acquired a kind of hubris that means they think they are
good at everything, and don't recognise the difficulty, complexity, or
value, of other fields of learning.  It's fine to be a polymath, but
that mostly means knowing how much there is you don't know.)

We should defer the question of voting systems to well-regarded civil
organisations for whom these questions are the primary focus, and who
are thereofore more competent: that means voting reform groups.
Almost uniformly, such groups recommend STV for multi-winner
elections.[0]

For the same reason, we should adopt a system which is widely used,
particularly by organisations whose governannce we expect to be
well-informed.  Again, that almost always means STV.

We should not be pioneering in this area.  We should make use of the
expertise of others, and follow their lead.  The Board appears to
agree with me, and I intend to proceed accordingly.


> At the very least, it would seem to me prudent to craft a resolution
> which includes (a) some flexibility, so that the voting system can be
> changed more easily should there be reason to; and (b) which mandates
> making the full list of cast ballots public, so that pathologies in
> the elections can be detected.

The choice of voting system should not be left to the Secretary.
Currently, the proposal is to have the Board select STV.  If a future
Board wats to change its mind and select something else in future,
then that is quite possible.[1]

The Secretary's current practice is to publish the tally sheets which
enable re-analysis.  Do we really need that to be Board-mandated ?  I
asked this question a few days ago, proposing a paragraph codifying
existing practce, and there seemed little enthusiasm for it.


As for your detailed criticisms of STV: these are mostly criticisms of
AV (in UK Electoral Reform Society terminology), which is the
single-winner system that STV is derived from.  It is true that AV is
not a particularly good system, and that it is worse than
Condorcet-based systems.

AV's virtue over Condorcet is that Condorcet is very hard to count in
a nontrivial election without using computers.  This means that
Condorcet is not suitable for high-stakes public elections.  (And it
explains why civil society orgnisations which care about public voting
reform don't advocate Condorcet-based systems.)

It is not surprising that AV produces somewhat different answers in
some close-run DPL elections.  I don't think this demonstrates a
fundamental weakness in AV, even though I prefer Condorcet.  (Of
course to say that AV's answers are wrong and Condorcet's are right,
is rather tendentious.)

It is also not surprising that a very widely adopted system like STV
would produce ocassional suboptimal results.  Although I don't accept
the specifics of your example (you are overstating what happened), I
don't find this cause for concern.  The analysis you pointed me to in
August, of the Burlington 2009 election, IMO is devoid of
understanding of the political context and makes serious errors in
trying to predict even what approval voting would have produced.


Going on to those references you provided in August.  They were to
people who advocate range voting for single-winner elections.  As I
said in private email, I find it difficult to take seriously anyone
who proposes range voting for single-winner elections.

As I say above, even approval voting requires a difficult tactical
analysis, in order to cast an effective ballot.  Voters need to know
where to put their cutoff.  Range voting poses the additional problem
that the most effective ballot ranks every candidate either 0 or 100%.
This is very counterintuitive for voters and few people will vote that
way.  I think this is a critical flaw in range voting.

All of the references you supplied used the term "IRV" for what I'm
calling AV.  This is a peculiarly American term.  I also observed that
many of the Wikipedia pages on voting systems have obviously been
written by range or approval voting advocates.

I don't understand why range voting (and for that matter approval
voting) have such a following in the US.  Outside the US, they are
hardly taken seriously as voting systems.  As I said in my email, I
think this may be some kind of fallout from the US's generally
dysfunctional polity.  (My most paranoid thought is that perhaps range
voting is being advocated to provide FUD about voting reform; the
range voting advocacy pages seem much more hostile towards AV than
they are to the real-world competitor, FPTP aka plurality.)

Ian.

[0] Sometimes people do advocate additional member systems or even
party lists, both of which are obviously unsuitable for SPI.

[1] Personally I think the voting system should be entrenched in the
bylaws but I have given up trying to persuade people that the Board
election system should be defended against the Board.

-- 
Ian Jackson <ijackson at chiark.greenend.org.uk>   These opinions are my own.

If I emailed you from an address @fyvzl.net or @evade.org.uk, that is
a private address which bypasses my fierce spamfilter.


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