[EM] Does Top Two Approval fail the Favorite Betrayal Criterion
jameson.quinn at gmail.com
Fri Jun 7 16:10:08 PDT 2013
Let's just drop this. You're technically wrong but substantially right, and
I don't see what's to be gained by convincing you of that that's worth the
time I think it would take.
As to the name thing, you called me "James". No big deal, really. I made
the "Joe" joke, then you didn't realize what I was talking about and
implied I was serious. Misunderstanding.
2013/6/7 Abd ul-Rahman Lomax <abd at lomaxdesign.com>
> At 10:51 AM 6/7/2013, Jameson Quinn wrote:
>> I'm sorry, I don't want to get into an interminable back and forth with
>> someone who misuses my name and doesn't apologize, and prefers "you didn't
>> prove it!" to working anything out for themselves or asking nicely for
> Jameson, I responded substantially and in detail to your claim of FBC
> failure. You are not obligated to respond to anything. You showed nothing,
> not even a weak evidence, beyond the name "turkey-raising," just a claim.
> And if you are content with that, that's your privilege.
> For me, and so far, unless someone comes up with a plausible scenario, it
> stands as demonstrated that a claim of FBC failure for top-two runoff,
> based on a "turkey-raising" strategy, is meaningless. Turkey-raising, under
> Approval/runoff, does not establish FBC failure, because one could still
> vote for the Favorite without harming the strategy.
> As we will see more proposed usage of approval and approval methods with
> runoff voting, it's an important issue.
> Who misused your name? What are you talking about? What is to apologize
> for? It's "not nice" to point out that a point has not been supported? What?
> (no more original content below.)
>> 2013/6/7 Abd ul-Rahman Lomax <<mailto:abd at lomaxdesign.com>a**
>> bd at lomaxdesign.com <abd at lomaxdesign.com>>
>> At 06:28 PM 6/6/2013, Jameson Quinn wrote:
>> 2013/6/6 Abd ul-Rahman Lomax <<mailto:abd at lomaxdesign.com>a**
>> bd at lomaxdesign.com <abd at lomaxdesign.com>>
>> Subject was: Re: [EM] Someone thinks that Approval should meet the Mutual
>> Majority Criterion
>> James does not help us out with a description of why it fails.
>> Should I start calling you Joe now? :)
>> You may join any club that will admit you. Ask Michael.
>> Others have said how it fails: through a turkey-raising strategy.
>> Implausible, unlikely, as you may have it; but still clearly possible.
>> Actually, that was not said recently. It's not only implausible, it does
>> not appear to violate FBC. That is why I have asked for specifics.
>> Favorite Betrayal Criterion:
>> A <<http://en.wikipedia.org/**wiki/Voting_system<http://en.wikipedia.org/wiki/Voting_system>
>> system satisfies the Favorite Betrayal Criterion (FBC) if there do not
>> exist situations where a voter is only able to obtain a more preferred
>> outcome (i.e. the election of a candidate that he or she prefers to the
>> current winner) by insincerely listing another candidate ahead of his or
>> her sincere favorite.<<http://en.**wikipedia.org/wiki/Favorite_**
>> Scorevoting.net (article by Ossipoff and Smith):
>> Voters should have no incentive to vote someone else over their favorite.
>> After my usual carping about absolute standards like "no incentive" --
>> Space Aliens can provide strong incentives -- I don't see how a
>> turkey-raising strategy with an Approval primary involves betrayal of the
>> Favorite. It does involve "betrayal" of a lower preference.
>> I.e., primary unconditionally feeds top two to runoff, which is
>> vote-for-one. I.e., this is the Arizona system, without the Approval
>> Voter prefers A>B>C. Voter fears that if runoff is A vs. B, B could win,
>> so votes for C. This voter is going to wet his or her pants if C leads,
>> but, never mind, maybe in the runoff A will win, because these turkey
>> farmers are not going to vote for C in the runff.
>> But, now suppose this is an Approval primary, i.e, this is in Arizona and
>> it's a municipality that's implemented the system.
>> Never mind that turkey raising is something that turkey farmers in
>> Arizona would never admit to. Out in the Arizona desert, folks get along,
>> and are straightforward and honest with each other. But, just suppose they
>> try this.
>> Okay, how does it show up? They could vote for C, hoping to push B out of
>> the runoff. They actually can't do that, because of write-ins, which are
>> allowed, but, hey, they can dream, they could even dream of Space Aliens
>> telling them to vote this way. In fact, given that this is Arizona, that's
>> fairly plausible. Something about the cloud formations. No, wait, that's
>> New Mexico.
>> But a little detail about FBC. Sure, they could vote for C, but if what
>> they want is for A to win, which is the whole motivation for running this
>> devious plan, why don't they also vote for A? They are pushing for B to be
>> excluded, and, this way, they push with two candidates (or more).
>> from the Smith-Ossipoff page:
>> one can prove FBC-compliance by the following strategy: If betraying
>> favorite F in order to make X win is the plan, and if that plan actually
>> works, then the alternate non-betrayal plan of simply raising X to be
>> co-equal top with F (carried out by the same set of voters who planned to
>> betray F, using the same set of votes they planned on) also works to make X
>> win. Q.E.D.
>> There is no incentive to vote C above A, the favorite. Want to raise the
>> turkey, C, to exclude B? Fine. Also vote for A. No Betrayal.
>> Indeed, this is part of a more sophisticated system of utilities. A voter
>> who votes A,C is *actually preferring to see a runoff between A and C* over
>> B winning. They may *say* that they prefer B>C, we might speculate this
>> about them, but the Space Alien in their head has convinced them to vote
>> otherwise, and we don't know that there is anything in there except Space
>> If they think they need to bullet vote for C, they are not merely raising
>> turkeys, they *are* turkeys. That should be part of FBC: the voters must
>> not be turkeys. (Actually, it is, just not stated that way. There is some
>> debate about complex strategies, blah, blah. It's moot here, unless someone
>> wants to assert such a strategy.)
>> Turkey raising strategy is FBC violating in non-approval top two runoff,
>> but is risky there. Essentially, the faction that decides to do it must not
>> be large enough to whack A by voting for C. It would, therefore, take
>> collusion to be reasonably safe, and it would, therefore, risk losing A
>> supporters. (Does A tolerate this? B just might start getting a lot more
>> votes, and A might have trouble remaining in the top two. And if we really
>> want to study this, we'd need to start looking at underlying utilities. And
>> here we can start to recognize how blanket judgement of voting systems by
>> simplified criteria can be a hazardous business, which was my original
>> point on the CES list.)
>> Further, "failure is minor" is an issue when using voting systems
>> criteria to study voting systems. That's the problem with using the
>> criteria as absolutes.
>> Yes, it's an issue. Absolutely. The difference between failing badly and
>> barely failing, is often larger than the difference between barely failing
>> and passing. But that doesn't mean you shouldn't be clear about the
>> Of course we should be clear. If a system *technically* violates a
>> criterion, but does not substantially do so, we should say exactly that. We
>> would never say that it does not violate the criterion. However, here, an
>> approval primary does not appear to violate the criterion. The "betrayal"
>> is of a lower preference, not the Favorite.
>> I did not give examples because I'm not asserting failure. Someone who is
>> asserting it, I'd prefer that they at least show an example. It would be
>> generous to cover the underlying utilities motivating the behavior, but
>> I'll do that if the writer doesn't. (Or will infer them and might show that
>> they do not significantly motivate the behavior, as a rough and nonspecific
>> analysis is telling me.)
>> 2. Top two approval where a candidate with a majority can win, otherwise
>> two candidates advance.
>> Still fails, although it's slightly better.
>> From what point of view? *How* is it better? *How much* better?
>> If any candidate has a majority, there is no FBC failure. If not, you
>> have system 1, which can fail FBC as explained above. Since that is only
>> part of the time, it is only partly as bad.
>> Once again, it appears to me that Jameson is asserting this because he
>> has not looked at an actual example, but is running off steam from *other
>> situations.* There was no "explanation above." There is now. If it's not
>> what Jameson had in mind, he's completely welcome to supply the scenario
>> and explanation. For reference, here is "system 1", as defined by me and
>> quoted by Jameson:
>> 1. Top two approval where two candidates advance to the general election.
>> This fails FBC.
>> QNED, quod non erat demonstrandum, this is not demonstrated.
>> 3. If write-in votes are allowed in the runoff, the primary is actually a
>> nomination device, not the actual election. The actual election being
>> Approval, the combination must satisfy FBC if Approval does, and it does.
>> This is true... but only if there's a hard threshold for making it to the
>> second round. That is, "all candidates with over 1/3 approval advance", or
>> some such; and if there are fewer than 2 such candidates, the highest
>> approval wins in the first round.
>> No. Threshold has nothing to do with it. If the primary is only a
>> nomination device, it is like petition requirements or partisan primaries.
>> Understand that this is like the Arizona proposal, but with Approval in the
>> final election. If the final election is Approval, Approval satisfies FBC,
>> because the voters may still vote for their Favorite in the general
>> election. There is no cost to that, and by the rule that a method satisfies
>> FBC if there is a simple way for the voter to actually vote for their
>> Favorite and not betray the Favorite by voting for someone else *over* the
>> Favorite, and gain as good an expected result, then FBC is satisfied.
>> If the primary is not considered as part of the election process, then
>> sure, it could consist of shooting any candidate with an even number of
>> votes, and it would not cause FBC failure.
>> "Election process" reasonably includes any process prior to a
>> deterministic poll. The primary is, then, "part of the election process,"
>> but is not the deterministic poll. We do not state that a voting system
>> fails a criterion merely because of voting system details that still allow
>> the test of the criterion. As an example, I have often claimed that
>> repeated ballot, no eliminations, majority required to complete, satisfies
>> the Condorcet criterion. This obviously must apply to the final poll, not
>> to prior ones, because voters can and will shift their preferences, new
>> candidates may be nominated, etc. It would apply to any *persistent*
>> preferences, if expressed consistently. The definitive test is in the final
>> But if you are considering it as part of the election, you can't just
>> make it up as you go along. A hard threshold, or a threshold based on a
>> mathematical function of the top candidate's votes alone, causes no FBC
>> failure. A set number of candidates advancing causes FBC failure, though
>> not a particularly serious one.
>> (If write-in votes are allowed, in this concept, the runoff must also be
>> Arizona had a method up for legislative passage that would have allowed
>> municipalities to use a two-stage voting system with an Approval primary,
>> top-two advancing to the general election with ballot placement, and,
>> apparently, write-ins allowed in the general election (as well as in the
>> primary). The primary has no majority test, it is top-two plurality, but
>> voters may vote for as many candidates as they choose. The runoff is
>> standard vote-for-one.
>> So, first of all, does this method fail FBC? If so, is the scenario
>> plausible for real voters? These are nonpartisan elections.
>> I'm not seeing any actual analysis here, just authoritarian statements.
>> So? Right and wrong are not decided by word counts or votes.
>> Well, ontologically, "right" and "wrong" are only words, meaningless
>> outside of definitions, not absolutes, but rather stands, judgements,
>> opinions, models, etc., that are either useful or not. And this, too, is a
>> "Authoritarian" might be thought of as "bad." Not if one is an authority
>> and is careful! Helpful authorities will explain the foundations of their
>> knowledge.... and if they overlook this, they will surely provide it, when
>> asked, if practical.
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