[EM] Hare (aka IRV) versus STAR
robert bristow-johnson
rbj at audioimagination.com
Thu Apr 11 05:32:52 PDT 2024
I guess this is evidence that Michael has plonked me.Powered by Cricket Wireless------ Original message------From: Michael OssipoffDate: Wed, Apr 10, 2024 21:42To: Chris Benham;Cc: Forest Simmons;Greg Dennis;James Gilmour;Kevin Venzke;Kristofer Munsterhjelm;Toby Pereira;election-methods at lists.electorama.com;robert bristow-johnson;Subject:Re: Hare (aka IRV) versus STAROr is the problem of that an acceptable runoff-loser knocking the acceptable runoff-winner out of the runoff there in STAR too? That hadn’t occurred to me. If it’s so, it’s another pitfall of STAR’s runoff.On Wed, Apr 10, 2024 at 18:26 Michael Ossipoff <email9648742 at gmail.com> wrote:On Wed, Apr 10, 2024 at 18:04 Chris Benham <cbenhamau at yahoo.com.au> wrote:
Michael wrote:
But STAR is better than Hare because:
It retains some amount Score’s merit.
No it doesn't. Score meets Favorite Betrayal and Participation.
STAR trashes those just for Condorcet Loser. I said “some”, not “all”.e.g. If there are unacceptable candidates, then just give max to the acceptables, & zero to the unacceptables.IRV? Try to rank the acceptables in order of winnability. …trying & hoping to match the ranking-order of the other preferrers of some of your acceptables.Questionable guesswork. An intractable strategic morass.
I could even make up a new criterion just to encapsulate the
horror of STAR.
The Favourite Ultra-Betrayal Criterion:
*Voters should never have any strategic incentive to vote their
sincere favourite as low as possible*.
Yes,, & isn’t that true with *any* runoff? It occurred to me too, I don’t like it. I much prefer Score to STAR. … completely reject runoff with Approval. …unless a jurisdiction insists on it.I much prefer Approval to Score, for minimalness & unarbitrariness.
Hare should be much easier to sell to anyone with any intelligence
or common sense because STAR is obviously
so silly and arbitrary.See above.
Where as Hare just seeks to replace the Single Non-Transferable
Vote with the Single Transferable Vote, keeping compliance
with Plurality, Dominant Candidate, Clone-Loser, Later-no-Harm and
Later-no-Help but losing Participation and Mono-Raise to gain
Dominant Coalition (and therefore Majority for Solid Coalitions)
and Dominant Mutual Third and Clone-Winner.
It has what Woodall referred to as a "maximal set of properties".
It's ok not to like it if you are a fundamentalist about some
criterion
compliance it doesn't have (like Condorcet or FBC) but not to
suggest that complete garbage like STAR is in some way preferable.
Chris Benham
On 11/04/2024 5:04 am, Michael Ossipoff
wrote:
On Tue, Apr 9, 2024 at 17:31
Chris Benham <cbenhamau at yahoo.com.au>
wrote:
[quote]
Score is Approval with a "I
wish to weaken the effect of my vote for the sake of being
more sincere/expressive" box/button.
[/quote]
If that’s how you want to
vote in Score, then suit yourself.
The right use of Score:
Use only min & max
ratings. i.e. Use Score as Approval.
…with the difference that,
when it’s uncertain whether or not a candidate deserves
approval, you can give hir partial approval, by an
intermediate point-rating.
Nice, sometimes convenient,
because, otherwise, the only way to give someone partial
approval would be probabilistically.
But Score loses Approval’s
absolute minimalness, & unique unarbitrariness.
Much better to let the
voters deal with such things for themselves with the
absolutely minimal handtool, than to use some arbitrary
& (somewhat or greatly) complicated definition, rule
& count. …with the consequent expense & count-fraud
vulnerability.
So it is strategically equivalent to
Approval while being more complicated and less fair.
More complicated, yes.
I strongly oppose a runoff for Approval, but
some jurisdictions might insist on one.
…likewise Score.
It’s true that it somewhat increases
Condorcet-efficiency & Social-Utility (SU), but it
brings great strategy-complication, including the loss of
FBC compliance.
But STAR is better than Hare because:
It retains some amount Score’s merit.
It’s much, much simpler than Hare, resulting
in much better count-fraud security.
It’s much less expensive to administer &
implement than Hare.
It’s much simpler to describe its workings
when proposing it.
And Approval has a quite good reputation here because
it meets Favorite Betrayal (aka FBC) and compared
with FPP the winner
will strongly tend to have higher social utility and
be much more likely a sincere Condorcet winner.
Also, and not unrelatedly,
it has a bias toward centrists that some people think
is wonderful.
But some people seem to think that adding a Top-Two
Runoff (automated in the case of STAR) to Score (to
make STAR) is just
a harmless little gimmick that just makes the method
"a bit more accurate", brings it into compliance with
Condorcet Loser
and so must make it more "Condorcet efficient".
("Sky-high" according to CLC here).
But actually it makes the method profoundly different
and very bad. It seems to me that the inventors of
STAR must have been
motivated by three priorities:
(1) the method isn't Hare,
(2) the method, in a purely technical and completely
useless way, apparently meets Mono-raise (aka
Monotonicity).
(3) subject to being saleable to and understood by
not-so-deep thinkers, the method be as bad as
possible.
From the "equal-vote" website: https://www.equal.vote/
Ranked
Choice Voting, where voters rank candidates in order
of preference has been lauded as a solution, but in
elections where the third candidate is actually
competitive, vote-splitting
remains a serious issue and
RCV only offers a marginal improvement compared to a
primary and general election with Choose-One
Plurality voting.
Luckily,
many voting methods are can effectively prevent
vote-splitting. As it turns out, when voters can
weigh in on each candidate individually, when all
ballot data is counted, and when voters are able to
show equal preference, vote-splitting can be
eliminated. All voting methods which do this pass
the Equal Vote
Criterion,
including STAR Voting,...
The "Equal Vote Criterion" is just propaganda
nonsense: https://electowiki.org/wiki/Equal_Vote_Criterion
The
Equal Vote Criterion or Equality
Criterion is a voting method
criterion which
requires that a voting method ensure that every
voter may cast a vote which is as powerful as a vote
cast by any other voter. Voting methods which pass
the Equal Vote Criterion do not exhibit vote-splitting or the
"Spoiler Effect," ensuring that every vote can cast
an equally
weighted vote.
Choose-One
Plurality Voting (First Past the Post) and Instant
Runoff Voting (often referred to as Ranked Choice
Voting) do not satisfy the Equal Vote Criterion.
This is just dishonest blather. If anything meets this
very vague and confused "criterion" IRV (aka Hare)
certainly does.
The classic scenario that motivated some people get
negative about Hare (and also methods like Min-Max
Margins):
49 Bush
24 Gore
27 Nader>Gore
Gore>Bush 51-49, Bush>Nader 49-27,
Nader>Gore 27-24.
Hare eliminates Gore and elects Bush, so the Nader
voters whose Gore> Bush preference was strong had
incentive to use the Compromise
strategy and vote Gore>Nader ("betraying" their
sincere favourite). If the method was Approval they
could have approved both Nader and
Gore, preventing the election of Bush without having
to vote their sincere favorite below equal-top.
But in this type of scenario STAR does no better than
Hare. The Nader voters would have incentive to give
Nader zero points.
"Traditionally" Hare's vulnerability to Push-over
strategy has said to be a result of it's failure of
Mono-raise. But STAR is much more vulnerable
to Push-over.
Say you are sure that your favourite will make the
final two. In that case then you have incentive to
give every candidate that you are sure your
favourite can beat 4 or 5 stars. If 5 stars then you
are relying on you favourite winning the runoff
without your help, but if 4 stars then you might
fail to get one of the predicted sure-loser turkeys
into the final.
In a Hare Push-over strategy scenario, the strategists
rely on their favourite winning the runoff against
their own votes, i.e. with their votes supporting
the turkey against their favourite. This makes it much
more risky (more likely to backfire) and difficult to
coordinate than is the case with STAR.
The equal-vote site has a link to a quite ok video on
the Favorite Betrayal Criterion. I find that weird
and misleading, because STAR badly fails FBC.
https://www.youtube.com/watch?v=JtKAScORevQ
From https://www.starvoting.org/
Why
STAR Voting?
Voting
reform is the keystone. A single cause with the
potential to empower us to be more effective on
every other issue we care about.
Honesty
is the best strategy. Strategic voting is not
incentivized.
Even if
your favorite can’t win, your vote helps
prevent your worst case scenario.
Highly
accurate, no matter how many
candidates/parties are in the race.
I'm not sure exactly what "accurate" is supposed to
mean, but I refute the suggestion that these claims are
more true of STAR than they are of Hare.
In the poll I will vote STAR below Hare and Approval and
all the Condorcet methods.
Chris
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