[EM] Some thoughts on Condorcet and Burial

[C.Benham]

Michael,

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

In the scenario I specified, there is a sincere CW. It is the candidate 
that is voted the CW (also the FPP winner).

Nearly everyone always assumes that (as long as the balloting rules 
allow voters to rank as many candidates as they wish and especially if 
the method
meets the Condorcet criterion) that a voted CW is always the sincere CW.

So the assumption of "a lot of Condorcet enthusiasts" I was referring to 
is that when there is no voted CW (because there is a voted top cycle) there
is very likely a "sincere CW" (and that that is a big deal).

So then they hypothesise about the voted top cycle being created by some 
"offensive strategy" (aimed at thwarting the election of this sincere CW
"rightful winner") that needs to be thwarted and/or deterred.

> M: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.
>
>
Obviously the individual voter would like to see their strongest 
pairwise preferences have as much effect as possible, more than their 
weaker ones.
Assuming that not all the voter's pairwise preferences have exactly the 
same strength, we can logically infer that the strongest ones are those 
for candidates they vote below no others
versus those they vote above no others.

The points and value of rank-balloting in general I would say: to 
minimise the number of involuntarily "wasted" votes, to elect the 
candidate that most likely maximises utility,
to minimise incentives for voters to falsify their preferences (or to 
conceal any of their serious preferences) and to minimise undesirable 
nomination incentives.

Chris













On 8/12/2023 4:12 pm, Michael Ossipoff wrote:
>
>
> 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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