--- Juho <juho4880@yaho...> a écrit :
> >> Do you have a verbal (natural language) explanation why D is better
> >> than A and C. This scenario could be an election in a school. One
> >> class has voted A>B (A and B are pupils of that class), another class
> >> has voted C>D, the teacher has voted D>B. What should the teacher
> >> tell the C>D voting class when they ask "didn't you count our votes"?
> >> Maybe this is clear to you. Unfortunately not as clear to me. The
> >> teacher vote seemed to be heavier than the pupils votes :-).
> > The question doesn't make any sense from them, unless first>second
> > preferences are really worth so much more than other preferences.
> > The C>D
> > class didn't just vote C>D, they also voted D>A and D>B. They can
> > make the
> > same complaint just as easily as long as anybody wins except for C.
> > And in this scenario you don't get a C win by "counting" C>D.
> Correct, C>D voters want C to win the others. I didn't understand
> your last sentence (in winning votes?).
My whole point is that C>D voters aren't going to complain about random
things unless they perceive they were harmed somehow. And it isn't at all
clear that C>D voters are *harmed* by the election of their second choice,
unless there was some way that they could have gotten their first
choice (that doesn't involve flipping a coin between him and a candidate
not liked at all).
> >>> You are saying that the election method should respect the C>D
> >>> voters'
> >>> nearly unanimous belief that C is better than D. If this is not for
> >>> the benefit of the C>D voters then for whose benefit is it?
> >> Yes, but this has nothing to do with the (IRV like or some other
> > Even if so I still ask this question.
> Ok, this was for the benefit of the C>D voters. Were there some
Yes, there would be consequences if somehow it were to the benefit of the
C>D voters to wonder why D was allowed to win. We would need to be able
to answer them. And we could go on to examine what negative strategic
incentives are created by causing the C>D voters to worry about this.
> >>>> What's the "not catastrophic = OK" doctrine? What is considered
> >>>> noise?
> >>> "Not catastrophic = OK" is the attitude you seem to present in
> >>> particular
> >>> in response to A winning given 7 A>B, 5 B, 8 C. Basically when a
> >>> candidate
> >>> loses an intuitively important pairwise contest only by a little,
> >>> it is
> >>> OK for that candidate to win anyway.
> >> I'd say this is a close race.
> > I know you would. I don't feel this is a good excuse.
> Excuse to what?
An excuse to say it doesn't really matter who wins.
To my mind this is the main problem. Margins thinks a contest is less
important the closer the match is. But that's not how people generally
determine which contests are the important ones.
> >> A wins in margins since it is only two
> >> votes short of being a Condorcet winner. That is one possible very
> >> sincere measure of who should win an election where the opinions are
> >> cyclic. The election of A may leave someone wondering if some
> >> strategic insincere moves could have changed (falsified) the outcome,
> >> but despite of this it is easy to claim that the algorithm picked the
> >> best winner.
> > As long as you have a "possible measure" then it's easy to claim that
> > someone is the best winner. In this scenario I don't think this is
> > very
> > convincing logic; I think many or most people would immediately see an
> > issue with A winning.
> Would that be an issue if the votes would have been interpreted to be
Yes. It makes no sense to me for A to win when C is in this election.
It takes a very obscure explanation to try to argue that the situation
of candidate B makes A a better winner than C.
> My current understanding is that with sincere votes your ideal
> winning candidate is the one that winning votes elect (or something
> close to that). My ideal selection is closer to margins. Ok to have
> different opinions here (and maybe different functions for different
Well I'm trying to do a little better than just state my opinion
about which is better.
> >> (1000 A>B, 1000 C>D, 1 D>B)
> >>> If you agree that C>D voters want D to beat the other candidates,
> >>> then
> >>> they should be allowed to elect D. From *their* perspective it
> >>> makes no
> >>> sense to require that D must have some support against C to beat
> >>> other
> >>> candidates.
> >> Yes, the C>D voters want D to beat A and B. They would be happy if D
> >> would be elected instead of A or B (unconditionally without
> >> considering how people voted between D and C). But their next
> >> question after there is an agreement that D beats A and B would be if
> >> they could go even further and elect C instead of D. Their feelings
> >> are quite strong/unanimous here.
> > And I have said repeatedly that in this scenario, you can't get a C
> > win
> > out of this. Would the C>D voters prefer an A-C coin toss to getting
> > their second choice? I doubt it. We can't know for sure. Neither can
> > they; the info isn't on the ballot. This is hardly a basis for a
> > complaint.
> In winning votes D won while margins tossed a coin between A and C.
> In wv the last voter could pick any of the candidates. The C>D
> voters' coin toss preference depends on their utilities (that are not
> known) as you say. Tossing a coin between all the candidates (the
> last voter picking any candidate is about a coin toss) would most
> probably give lower average utility sum than picking the winner among
> A and B.
I don't really agree with such arguments, since if we make decisions this
way then voters are better off ranking their most viable choices relatively
higher so that the utility looks better.
Also, this part of the discussion was about some faction of the voters
having a complaint. This utility argument seems separate.
> >>>> In this election I don't thing there were candidates that could be
> >>>> called "good compromise candidates" since all voters except one
> >>>> gave
> >>>> support to the candidates of their own party and left all the
> >>>> others
> >>>> tied at the last position.
> >>> If an election is tied, isn't it okay for one more voter to break
> >>> the
> >>> tie?
> >> Yes, but in this example it feels more natural to me to think that A
> >> and C were tied and consider B and D to be less preferred than the
> >> other two.
> > Again I wonder what the point of second preferences is supposed to be
> > if the win should be limited to factions' first preferences.
> > In response to that you may say it isn't about first preferences, that
> > it's about the matrix. But here we're looking at an actual scenario
> > and
> > asking what voters were thinking when they voted and how they feel
> > afterwards.
> Ok, talking about the feelings, not about the algorithm. I don't know
> how we should interpret first and other preferences in the sincere
> votes/utilities. Do you maybe think that people generally have a
> bigger utility difference between the first and second preferences
> than between second and third, or what? If we want to discuss these
> things we should probably concretely present the sincere opinions as
> utility values to set a solid basis for the discussions (=> e.g.
> A=100, B=80, C=70 instead of A>B>C) (I note that you used "B>>>C>A"
> notation later).
No, I don't think we should interpret there to be utility gaps in the
rankings. I am saying *you* seem to think this.
> >> (20 A, 15 A>B>C, 10 A>C>B, 35 B>C, 20 C>B)
> >>>> Someone called this a game of chicken. Not a nice feature of a
> >>>> voting
> >>>> system. If the newspapers publish the results of the poll and tell
> >>>> that C>B voters have the option to vote strategically C>A>B, what
> >>>> should the B>C voters do? Should they truncate in order to
> >>>> eliminate
> >>>> the risks? Those C>B voters that want C to win more that they
> >>>> fear A
> >>>> to win (utilities e.g. C=100, B=50, A=40) may vote strategically
> >>>> even
> >>>> if there would be a risk of some B>C voters using the counter
> >>>> strategy.
> >>> The same newspapers would say that B>C voters should truncate. And
> >>> then
> >>> it doesn't work. (This is assuming not just that B voters do plan
> >>> to give
> >>> that many votes to C, but that C voters trust that they will.)
> >> Do you recommend the "B>C" voters to betary C and vote "B"? Note that
> >> according to the poll "C>B" voters were not planning to vote
> >> strategically (not yet at least, although they might decide to do so
> >> after they hear about this possibility).
> > I believe a fair number of B>C voters would believe it is a good
> > idea to
> > betray C; I don't think they would think of it as "betrayal."
> What then, "justified precaution" or "necessary precaution" or "just
> regular voting behaviour with this method"?
Just "I don't need to vote for that candidate, so why would I." Note that
this is only for supporters of the better-established or more viable of B
> > I think C>B voters retaliating against this possibility would be quite
> > stupid. I don't think there is enough ability to gauge what B>C voters
> > will actually do, since truncation doesn't require much conscious
> > strategy.
> > I don't think the C>B voters' "counterthreat" to truncate would
> > have an
> > effect on the B voters. Mostly because the C>B voters are fighting
> > over
> > nothing but principle. They would be threatening to spoil the race
> > just
> > to get B voters to express their true second preference (which they
> > assume to be C).
> Ok, you assume wide use of strategic voting (= not ranking /
> betraying C).
If you call that "strategic voting" then sure.
> >>>> - I can't really comment the strategies if I don't know what the
> >>>> sincere opinions of the voters were. Could you give some set of
> >>>> sincere opinions that led to these strategic votes.
> >>> I did this already. What did you not like? That I didn't clearly
> >>> specify
> >>> the division of the 24 B voters between B>A sincere and B>C sincere?
> >> I think you didn't do that fully yet. Based on your comment I assume
> >> that the sincere opinions could be e.g. 12: B>A and 12: B>C. I assume
> >> that B is a centrist candidate and therefore most C supporters might
> >> vote C>B (like you said). But this does not explain yet why A voters
> >> would (in real life) all be of (sincere) opinion A>B=C. Am I correct
> >> to assume that the majority of the A supporters actually feel A>B>C
> >> (or is there some explanation why this is not the case).
> > Yes, you may assume that the A voters' sincere preference order is
> > A>B>C.
> > However, I do not see B as a "centrist" candidate. B is the major
> > party
> > opposition to A.
> I proposed one set of sincere opinions below. If they are not what
> you thought the sincere votes are, please propose an alternative set
> (this is your scenario after all, so you take the lead).
I want to reiterate that I don't find the sincere votes to be important
here. This is because I'm not aware of any set of sincere preferences,
polling information, or resulting strategic voting where the result of
the 49 24 27 scenario seems acceptable.
When you adjusted the scenario to something more "realistic" in your
opinion, you were able to get the same situation. So the question of
realism is no longer important in my mind.
> >> It would be really helpful to have the sincere opinions, and possibly
> >> also recommended strategic voting patterns stable and clearly listed.
> >> It is hard to discuss the possibilities if one has only the final
> >> outcome of the election available (that is expected to contain
> >> strategic votes).
> > I assume you recall the polling information I suggested.
> > sincere A>B>C: recommended to truncate
> > sincere B>A>C: recommended to truncate
> > sincere B>C>A: recommended to truncate at least if B>C preference
> > gap is
> > large
> > sincere C>B>A: recommended to vote C>B>A
> > The point of the scenario is probably clearer if sincere B>C>A voters
> > are thought to be B>>>C>A voters. C is supposed to be truly
> > unlikely to
> > win.
> >>> I don't know why you ask this. Information isn't perfect; your
> >>> modification
> >>> of my scenario to make it "more realistic" seemed to primarily
> >>> have as
> >>> its goal, to make the point that the results of the election are not
> >>> very certain.
> >> Correct. That is why I keep asking. I don't expect the sincere
> >> opinions of the voters to be as in the votes in the example (they are
> >> too extreme), and you seem to agree with this. The sincere opinions
> >> are expected to be more balanced in large elections. And that has an
> >> impact on the vulnerability and strategic opportunities in the
> >> election. My target is to study how high the risks are in real life.
> >> That is why I put more weight on scenarios that can be from real
> >> life.
> > But again, you managed to create the same situation using "more
> > balanced"
> > opinions.
> Yes, the basic relations are the same, but the strengths are
> different, and in real life there are many kind of voters with many
> kind of opinions, and the probability of some (extreme) scenarios
> appearing may be low.
strengths are different: But this didn't make any difference.
there are more types of voters: Didn't make any difference.
probability of the scenario may be low: In my opinion, if the probability
of this scenario is low *under margins* it's mainly because candidates
like C realize they shouldn't enter the race because their own supporters
are not likely to risk giving them a pairwise win over a more centrist
If we see scenarios like this I'd say we're lucky. But we shouldn't expect
to see them if people see that they won't be handled well.
> >> It looks like the
> >> recommended general voting strategy is close to:
> >> - If you support the strongest candidate (X) of the party, then you
> >> should bullet vote
> >> - If you support the second strongest candidate (Y) of the party,
> >> then you should vote Y>X
> > My recommended general voting strategy for two frontrunners is to not
> > rank the worse one or anyone liked less.
> If you can, it would be nice to get a formal strategy recommendation
> for this (you had something in this direction earlier in this mail).
> Generic strategy guidance would be really useful. (Approval has some
> quite well described strategies.) Now I still struggle a bit e.g.
> with "frontrunner" (how to measure it).
Approval strategy involves estimating likelihood of a pair of candidates
being in a crucial tie. That is hard to measure as well.
In real life I believe it will be pretty clear who the "two frontrunners"
are, and if there aren't two clear frontrunners, then we have a real
multi-candidate race and should be grateful.
One basis for this strategy under WV is that if there are two frontrunners,
and people have the sense not to rank the worse one, then the less
preferred frontrunner can never win the election, and nobody has to lie
about who their favorite candidates are.
If you only added this feature to FPP I think it would be a halfway
decent method. It's basically a guarantee that an (essentially) two-
candidate race won't get screwed up.
> > If your favorite candidate is not a frontrunner but is likely to have
> > substantial strength, then in WV I *might* suggest compressing the top
> > ranks so that the better frontrunner is in equal-first. Under margins
> > I would suggest that you rank your favorite candidate below the better
> > frontrunner.
> > Reading this again I guess you are more concerned with candidates of
> > the same party. I would not say in general that you *should* truncate
> > if your favorite candidate is the leader. But you can benefit if other
> > voters believe that you *will* truncate in this situation, because
> > they
> > will feel forced to support the frontrunner. In margins (or IRV)
> > they may
> > feel forced to rank the frontrunner in first.
> What I'm thinking here is if Condorcet will require all voters to
> consider and maybe use strategic voting or if it would be ok to just
> vote sincerely. Of course this depends on how well the election day
> opinions can be estimated, the tradition of the society etc.
Well, if two candidates represent one party and split the vote almost
any way, it could take very, very few voters to defect and spoil the
> > I do not think Condorcet (either type, even WV) really allows that
> > much
> > more potential than Approval for multiple candidates from the same
> > party
> > to be viable. I think in practice it would be too dangerous.
> This is not good news for the voting methods. If the elections only
> have two major candidates and some candidates that are too weak to be
> elected the method could almost as well be plurality.
I don't see it as that bad. I see we get these advantages:
1. If there's a left, right, and center candidates, and the left and
right are not sure of defeating the other, then the center should win
if neither left nor right achieve a majority
2. You can safely vote for candidates who are too weak to beat anybody
(even IRV has this)
3. You can safely vote for candidates who are strong enough to beat
somebody similar, but not strong enough to win the election (I put this
here for WV mainly)
I think the first one is the most important one.
> I however
> expect the voters to be a bit more dynamic so that there will be
> changes in opinions after the candidates have been nominated, and
> therefore exact planning is not possible.
I don't envision a lot of planning.
> (In a two-party country the election set-up may be more straight
> forward and the outcome easier to estimate than in a multiparty
> country. I have followed e.g. some two-round elections where the
> opinions have changed considerably during the long election process.)
Having two rounds makes a big difference.
> >> I think Condorcet methods are at their best in situations where
> >> voters can vote sincerely, not when strategic considerations start
> >> stealing space and time.
> > I guess I don't understand what you mean by this. People "can" vote
> > sincerely to the extent that strategic considerations don't force them
> > to do otherwise.
> > I guess you are just saying that you wish people would vote sincerely.
> I expect the people to be just regular people with some interest in
> strategies and relatively strong competitive instincts. But I'm
> hoping that in many societies (that of course consist of people) that
> are not too strategy oriented, and in elections where the set-up is
> not very clear (= there are multiple candidates that could win and
> the opinions are changing all the time) Condorcet strategies would
> not be worth playing with, and as a result the strongest trend would
> be to simply vote sincerely.
> Note that strategic voting is not something that would be controlled
> in some systematic way even today. For example in plurality elections
> many people vote sincerely the weak candidates that have no chance of
> winning although they have been told that they are in a way wasting
> their vote. I don't claim that these sincere, strategy-unaware etc.
> voters would change the system, but if we are lucky the strategic
> votes could be just waste of time. Possibly in some cases we could
> also prove that some strategies that were applied actually worked
> against the interests of the strategic voters.
I would say under plurality very few people vote sincerely, and those that
do mainly vote for candidates that we wouldn't expect to become viable
anyway, even if it were safe to vote for them.
Even with a top-two runoff I think you see a lot more sincerity than under
> >> (49 A, 24 B, 27 B>C)
> >> ...
> >> (30 A, 9 A>B, 6 A>C, 14 B, 8 B>C, 2 B>A, 25 C>B, 5 C, 1 C>A)
> >>>> These were intended to be sincere opinions that could be from real
> >>>> life. I thus planned to consider any any possible strategies (and
> >>>> strategic truncations) based on these sincere opinions.
> >>>> (These votes were intended to be a more realistic example of
> >>>> sincere
> >>>> opinions than your original example. Now I learned that the
> >>>> original
> >>>> example was not intended to be sincere. The example is however
> >>>> still
> >>>> valid as a more realistic set of sincere opinions.)
> >>> I just don't see the point yet. You've added in some other ballot
> >>> possibilities and you made C a bit more viable.
> >> The point is that when we take into account the inaccuracy of the
> >> polls, opinions that change in time (before the election day),
> >> negative reactions to strategic plans, having few such voter groups
> >> present that have different targets than what are present in the
> >> simplifies scenarios, and having multiple differing opinion poll
> >> results available, then the cases become more complex and anything
> >> can happen. Reliable strategies become less reliable. In such
> >> circumstances the Condorcet methods are expected to perform better.
> >> Sincere voting is more often the best strategy to apply. My ideal
> >> outcome of this kind of analysis would be that in many societies
> >> Condorcet would be practically strategy free. Strategies and counter
> >> strategies would not be applied since they would not be considered
> >> efficient, and they would maybe be considered bad manners that
> >> everyone would try to discourage (e.g. by explaining that it is more
> >> likely to lead to worse relults than to better results to the voter
> >> in question).
> > Well, again, I am focused mainly on favorite betrayal incentive,
> > because
> > it is such a safe and reliable strategy. I don't think it would be
> > realistic to guess that people wouldn't be able to determine who the
> > frontrunners likely are, and that is all you need to know for this
> > strategy.
> But is is also not always clear that order reversals would pay off.
It would hardly ever pay off, since you don't expect your candidate to
be viable anyway. It doesn't matter. Why risk driving into a wall just
because it might not kill you?
> The opinion polls are always outdated, there may be several of them
It hardly is an improvement if they mistakenly believe that their candidate
*is* harmless to vote for.
> There could also be many different recommendations for strategic
> voting (just like in this list concerning many voting methods
> although people here are expected to be some sort of experts of this
> area :-)).
In this realm I can't think of any. You suggested perhaps the B voters
would be well-advised not to truncate. But that is advice for a different
segment of voters than the ones who would want to use favorite betrayal.
> (But I'm thus hoping all this would be noise and regular citizens
> could in most cases simply vote sincerely without that causing them
> any fears and nightmares.)
I think voters will be more inclined towards being cautious than sincere.
> > Then I can't see how favorite betrayal would generally be considered
> > "bad manners that everyone would try to discourage"; under FPP at
> > least
> > when you don't use favorite betrayal (when you realistically should)
> > it's called "wasting your vote." And I can hardly see how "wasting
> > your
> > vote" in this way leads to a better result even though it is sincere.
> From some point (not proven) at least Condorcet can be said to
> improve Plurality by allowing (in general, in most cases,...) to
> sincerely express their preferences.
I won't object to you saying Condorcet is better than FPP at this since
I am also trying to make the point that WV is better than Margins at this,
with respect to first preferences.
> >> The original (intended, exaggerated) sincere opinions could have
> >> been:
> >> 49 A>B>C
> >> 12 B>A>C
> >> 12 B>C>A
> >> 27 C>B>A
> >> Both margins and winning votes would elect B with sincere votes.
> >> In this situation the A and B supporters decide to vote (counter)
> >> strategically and truncate (with more or less valid reasons). (The
> >> end result / actual votes are exaggerated, but more realistic votes
> >> can be discussed later if needed.)
> >> 49 A
> >> 24 B
> >> 27 C>B
> >> Margins will elect A and winning votes will elect B. Your opinion
> >> seemed to be that winning votes is better since with margins C
> >> supporters would be tempted to vote B>C and thereby make B the
> >> winner. (Note that with these numbers at least 48 out of the 49 A
> >> supporters would have to vote strategically to generate the
> >> temptation for the C supporters to vote strategically.)
> > My issue is not simply that C voters have strategic incentive here.
> > It's
> > that the incentive is to abandon candidates who aren't frontrunners;
> > that it is practically risk-free; and that if the C voters don't use
> > the strategy, their sincere votes confuse margins into picking the
> > wrong
> > winner.
> I may analyse this later.
That might be helpful since I'm not spending all this time simply to
complain that some election method is vulnerable to a strategy.
> >> An alternative explanation to these actual votes could be that the
> >> sincere opinions were:
> >> 49 A>B=C
> >> 24 B>C>A
> >> 27 C>B>A
> >> This is a typical (exaggerated) left-right-right set-up. Both margins
> >> and winning votes would elect C with sincere votes.
> >> In this alternative the B supporters vote strategically and truncate.
> >> The actual votes are exactly the same as in the first case - this is
> >> thus just an alternative explanation to them.
> >> Now the fact that winning votes elects B makes it possible for the B
> >> supporters to apply the strategy while margins do not encourage
> >> strategic voting.
> > I don't see this as a wash. In both cases under margins (C voters
> > using
> > strategy or B voters not using strategy) the effect is achieved
> > basically
> > by threatening the voters to either vote someone as CW, or else be
> > punished
> > by having margins resolve the cycle badly.
> I didn't fully follow this. In this case C was the rightful winner
> (based on the sincere opinions), and B supporters could then change
> the result. The C strategies came only after this (and therefore
> maybe are less damaging).
What I am saying is that you seem to be saying it is all the same, who
other than God can really say what incentive is better or worse, etc. I
keep pointing out that WV consistently avoids favorite betrayal
incentive in these situations, and in response you point out that in
margins, one faction here shouldn't have truncation incentive. If margins
consistently has that quality then sure, that would be noteworthy.
In any case I find it humorous that the way margins' strategic incentives
operate in this scenario, is that voters must create a Condorcet winner
deliberately (either by not truncating or by favorite betrayal) to prevent
margins from handling the cycle. It's something like a refrigerator that
you have to remember not to put food in.
> > You ask "should we prepare for widespread strategic voting" in
> > Condorcet.
> > If you're referring to truncation then I'd say yes, it's almost
> > funny to
> > ask. People will truncate where they feel they can until you prove to
> > them it can never hurt them. You may even have to prove that it may
> > often
> > be useful. Otherwise why should they bother taking the risk of voting
> > for candidates they are trying to defeat?
> Sure there are also cases where truncation hurts the voter (e.g. the
> case where two Republicans truncate each others and the Democrat wins).
> Your words "voting for candidates they are trying to defeat" sound a
> bit as if the voters were thinking of being in an Approval election
> (where mentioning B means full support to B) or something similar.
In the above section I was thinking more of frontrunners. In particular
A voters truncating B, even though there is another weak candidate on
the other side of B.
> Isn't in natural in a society that is used to ranking based elections
> to vote A>B>C even if the voter would strongly dislike the idea of B
> winning A?
It's not about strongly disliking a B win, it's about how likely it is
that you need to help B or can gain anything by helping B (in comparison
to what you might lose).
> > You ask whether Condorcet is better than other methods if strategic
> > voting
> > is widespread. If people don't feel compelled to use favorite betrayal
> > strategy, and don't use offensive strategies that can backfire, then I
> > imagine it would be better than e.g. Approval.
> Do I read this right. "Condorcet with widespread truncation is better
> than Approval, and Condorcet can't do better than this"?
It sounds ok, but I'm not sure what you mean by "this."
If voters under Condorcet don't use offensive strategies (specifically,
burial of rival frontrunners below worse candidates) and don't use
favorite betrayal, then even if these voters truncate at the same rank
they would under Approval, I believe Condorcet would be far better than
I do not believe you can design a Condorcet method where filling out a
complete ranking is generally a good strategy. (If that is what you are
asking here.) And as I've said, even if you managed to design one I think
you would have an extremely difficult time convincing many voters to take
advantage of it.
I don't especially want to promote other methods here, but it seems
reasonable to note that my ICA method precisely intends to bring as
much Condorcet efficiency to Approval as possible, without inviting
favorite betrayal or much offensive burial.
Using approval to solve cycles isn't as sophisticated as determining
defeat strength, but approval does have in common with WV that candidates
or contests are considered more important when more people are involved
in voting for them.
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