[EM] Some thoughts on Condorcet and Burial

[Michael Ossipoff]

On Thu, Dec 7, 2023 at 20:13 C.Benham <cbenham at adam.com.au> wrote:

>
> The way a lot of Condorcet enthusiasts see things is that voters naturally
> have a sincere full ranking of the candidates
> (or certainly those with any hope of making it in to the Smith set), that
> we should assume that all those implied pairwise
> preferences are equally strong, or if not they are all nonetheless equally
> important.
>
> Incorrect.

…or, if “a lot of Condorcet enthusiasts” believe that, then “a lot of
Condorcet enthusiasts” are mistaken.

The whole strength, value & point of Condorcet, & rank-balloting in
general, is that we don’t have to express preference-strength, & that
preference-strength is irrelevant to the method’s purpose & the voter’s
intent & interest.

So, no, there’s no reason to assume anything about preference-strength,
even if you & “a lot of Condorcet enthusiasts” do.


> And that "normally" if all the voters give these rankings there will be a
> "sincere CW",
>

“Normally” there is a “sincere CW”.  That’s  why “normally” there’s a
“voted CW”.

but if the used method (that meets
> the Condorcet criterion) fails to elect this candidate due to some of
> voters declining to give their full strict rankings creating a
> top cycle which the method resolves by electing someone else then there is
> some huge problem.
>

If the “used method” is MinMax(wv), CW,Implicit-Approval, or MDDA, then
truncation of the CW won’t prevent hir election.

(…but maybe, if there’s humongous indifference in which case it doesn’t
matter a whole hell of a lot).

But is there “some huge problem” if the “sincere CW” loses? Nah , not
unless voters care about their expressed pairwise preferences being counted
& contributing to the winner by the definition of pairwise-count.


>
> I reject all that.  I think a better way too start looking at things is to
> assume that we have three factions of voters (each with
> its own candidate) that strongly prefer their favourites to the other two
> candidates who they consider to be about equally
> bad (and/or uninteresting) and so they are not inclined to do anything
> except bullet vote (Later-no-Harm or not).
>

But your assumption was that there’s a “sincere CW”. So now you’re
contradicting yourself & saying that there isn’t, due to indifference?

If so, then we needn’t cry if a nonexistent “sincere CW” isn’t elected.



>
>
> That has two big advantages. One, that probably it is more realistic. We
> are looking to replace FPP and most voters would
> probably be happy to continue voting for just one candidate.
>

You don’t live here. Pretty much everyone you talk to here says that they
dislike having to vote for one, when that one is a despicable lesser-evil.

>
>
>
> And two, with this model there can be no controversy as to who should win.
> Every method has no choice other than to
> elect the candidate with the most votes.
>
That sounds like the definition of Vote-For-1 (VF1),  but of course it’s
meaningless in reference to other methods.



>
> I think one mistake that Blake Cretney made quite a while ago (stemming
> from the mind-set I described at the beginning)
> was to classify truncation as a variety of Burial strategy.
>

Then Blake Cretney was mistaken. Truncation (failure to express
felt-preferences below some rank-position) can be strategic, or lazy,
 careless, hurried, etc.

…&, if strategic, it could be offensive or defensive strategy.

>
> The voting method should be very happy to assume that presumed (or
> imaginary) strict "preferences" that the voter chooses not to
> express on the ballot for whatever reason (barring some over-strong
> truncation or compromise incentives) simply don't exist.
>

It isn’t the voting system’s job to assume things.

What’s Condorcet’s job?

It’s to count all of everyone’s voted-preferences & elect the winner that
they point to.

Maybe you aren’t aware of it, but opponents of Condorcet always reject it
because offensive strategy can defeat a “sincere CW”.

…& so it’s desirable to either elect a “sincere CW” despite offensive
strategy (…as does MinMax(wv) if there’s strategic, lazy or hurried
truncation of the “sincere CW”.

…or deter burial strategy, as do MinMax(wv), CW,Implicit-Approval, & MDDA.

…via defensive truncation.

…& as the autodeterrent methods (when the best ones are found) will do,
without any use of defensive strategy.

Maybe it must be explained to some people that the purpose of Condorcet is
to elect that candidate who is preferred to all the others by more voters
than prefer that other to hir.

That’s how we count & honor every pairwise preference voted by every voter.

That’s the 1-&-only defined-purpose of the pairwise-count Condorcet methods.

You could design the completion-method for that defined purpose, or you
could choose it to do something pretty under the assumption that there’s no
“sincere CW”. That’s nice.

Of course that’s entirely your choice. But if you say that choice other
than yours is wrong, then you’re wrong.

>
>
> On the other hand egregious failures of  Later-no-Help should be looked on
> as being "suspiciously convenient".
>
> I think it could be useful to have a version of Later-no-Help that has
> been weakened enough for it to be compatible with Condorcet.
>
> More later.
>
> Chris Benham
>
>
>
>
>
>
>
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