[EM] Contextuality determines relative import of criterion.

[David L Wetzell]

I think it depends on what sort of election, what sort of political
environment.

Nonmonotonicity is low priority if the probability of it mattering is low,
because it's not likely enuf to matter for voter-strategy formation.  Thus,
with IRV+, in the relatively rare case of a competitive three way election
among the top three candidates, a 20% chance of non-monotonicity mattering
is not important.

Similarly, lots of stuff is a matter of sour grapes.  Ie, some group finds
out after the election that if lots of folks had voted differently a
certain way together, it could have had some unintended consequences.

Likewise, does it matter the incidence of FBC?  Is it the third party
dissenters who are given the incentive to betray their favorite, or is it
the members of the major party who chooses not to position themselves
around or near the true political center.

Also the no. of serious candidates in an eelction matters for the relative
import of stuff...

And so it seems that a lot of the attempts to derive analytically the
"best" election rule in a theoretical abstract manner have been a chasing
after of the wind...
dlw

On Mon, Jan 30, 2012 at 2:02 PM, <
election-methods-request at lists.electorama.com> wrote:

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> Today's Topics:
>
>   1. Re: Propose plain Approval first. Option enhancements can be
>      later proposals. (Kristofer Munsterhjelm)
>   2. Re: Propose plain Approval first. Option enhancements can be
>      later proposals. (Juho Laatu)
>   3. Which matters more: Getting/Figuring Out the Best
>      Single-Winner Rule or Incorporating More Multi-Winner Rules ASAP
>      in the US? (David L Wetzell)
>
>
> ---------- Forwarded message ----------
> From: Kristofer Munsterhjelm <km_elmet at lavabit.com>
> To: MIKE OSSIPOFF <nkklrp at hotmail.com>
> Cc: election-methods at electorama.com
> Date: Mon, 30 Jan 2012 07:46:01 +0100
> Subject: Re: [EM] Propose plain Approval first. Option enhancements can be
> later proposals.
> On 01/28/2012 09:13 PM, MIKE OSSIPOFF wrote:
>
>  On a related subject: The other thing lacking at EM, in
>> addition to mock elections, is support for claims that a criterion is
>> important. We hear, “I consider this criterion to be very important”. But
>> such
>> assertions need to be supported by explanation of _why_ you consider that
>> criterion important.  Why should others
>> consider it important? What practical problems are present in
>> non-complying
>> methods but not in complying methods? What would it be like to vote in a
>> non-complying method?
>>
>
> I don't think you can find any universal reason for why a criterion is
> important. The reasons have to be developed on a criterion-by-criterion
> basis.
>
> The logic for focusing on criteria is that no deterministic ranked method
> can pass all of Arrow's "ultimate criteria" (unrestricted domain,
> non-dictatorship, Pareto efficiency, and IIA), we have to either say "every
> method is equally good" (which is nonsense), or see how close we can get.
>
> We know that if some method X passes all criteria Y does and then some, we
> can suppose that X is better than Y. In game theory terms, X dominates Y.
> But if X passes some Y doesn't and Y passes some X doesn't, then who knows?
> It all becomes a matter of tradeoffs, and the relative value of each
> criterion is not very clear. Criterion failure may have implications for
> how the whole system using the method evolves, so Bayesian-regret type
> calculations may get the relative values wrong.
>
> Take Borda. It has a respectable Bayesian regret but is so vulnerable to
> cloning and voting strategy so simple that in practice, it does very badly.
> It invites parties to field massive numbers of candidates, so the party
> with the most people win.
>
> Still, I think we can see some patterns. We have absolute criteria
> (majority, Condorcet, mutual majority, etc), and relative criteria (FBC,
> monotonicity, independence of clones, etc). The former state possibly
> desirable properties. The majority criterion is part of majority rule, and
> mutual majority extends it from sets to candidates, for instance.
> On the other hand, the latter tends to involve the method behaving in a
> self-consistent manner, or freeing the voters or candidates from strategy.
> When a method fails monotonicity, you have two nearly equal ballot sets,
> and a change from one to the other that ought to make X's claim stronger,
> but X loses. The method is inconsistent with itself and "gets it wrong" in
> one of the two cases. Further, in a real election, we don't know whether
> the real result or the one from the hypothetical transformed election is
> the wrong one, so there's a chance the real result is dubious, too. Some
> people think that monotonicity is about strategy, but I think it's about
> the performance of the method, and about how it can justify (or not) its
> results.
> FBC is a strategy-related criterion. When a method fails FBC, that means
> that voters may have to rank their favorite artificially low to get the
> result they want. That means voters can't be absolutely sure they don't
> have to compromise. When a method is not cloneproof, that means
> uncoordinated entry or exit of candidates can make a great difference. The
> candidates know that even if they're completely alike each other, they can
> make the result change by joining or leaving.
>
> Beyond the absolute/relative distinction, I think we can also distinguish
> between "cheap" criteria (e.g. unanimity) and "expensive" ones (e.g. strong
> FBC, later-no-harm). If a method is built to pass an expensive criterion
> but thereby fail a number of criteria other methods pass, one should give a
> strong argument for why that's desirable. In your case, you give as your
> strong argument that by passing the FBC (which is expensive and excludes
> many other criteria), you free the voters from having to even think about
> ranking someone above their favorite.
>
> Passing strategy-related criteria gives a method undistorted data from
> which to act. Passing absolute criteria and consistency-related relative
> ones means the method will use that data well. But how much distortion the
> former removes and how well each latter criterion implies is not easily
> discovered.
>
> (At this point, some people try to get around methods failing certain
> criteria by saying "sure, it fails, but it doesn't fail where it counts".
> But it can easily lead to a lot of back-and-forth about what "where it
> counts" really means and what one really wants of an election method.
> Pass/fail, in contrast, is completely unambiguous. Either a method passes
> or it doesn't, and if a method passes a criterion everywhere, then
> obviously it passes it "where it counts", no matter where that might be.)
>
>
>
>
> ---------- Forwarded message ----------
> From: Juho Laatu <juho4880 at yahoo.co.uk>
> To: Election Methods Mailing List <election-methods at electorama.com>
> Cc:
> Date: Mon, 30 Jan 2012 11:21:45 +0200
> Subject: Re: [EM] Propose plain Approval first. Option enhancements can be
> later proposals.
> On 30.1.2012, at 8.46, Kristofer Munsterhjelm wrote:
>
> > We know that if some method X passes all criteria Y does and then some,
> we can suppose that X is better than Y.
>
> I don't think criteria are black and white in that sense. It is quite
> possible that a method that meets all but one of the "important" criteria
> that we have chosen is worse than a method that does not meet any of those
> criteria. The reason is that some vulnerabilities are not meaningful in
> practical elections while some can make the method totally unusable.
>
> I'd thus measure how well certain method meets some criterion rather than
> if it meeths that criterion absolutely in every theoretically possible
> sittuation.
>
> In cryptography the overall strength of a system is quite typically as
> strong as the strenght of the weakest link. In the same way the overall
> vulnerability level of an election method is typically close to the
> vulnerability level of the most problematic vulnerability of it. That means
> that the key target is to improve the worst vulnerabilities, not to try to
> reduce the number of vulnerabilities against some chosen list of criteria,
> nor to agree on which criteria must be abolutely met fully (unless there
> are some criteria where every theoretical vulnerability is automatically
> also a serious problem also in practical elections).
>
> > (At this point, some people try to get around methods failing certain
> criteria by saying "sure, it fails, but it doesn't fail where it counts".
>
> "Doesn't fail where it counts" or "the vulnerability is not too bad".
>
> > But it can easily lead to a lot of back-and-forth about what "where it
> counts" really means and what one really wants of an election method.
>
> Yes, unfortunately so. My approach is to look at the environment where one
> wants to use some particular method, and then see the level of damage that
> the vulnerabilities cause in that particular environment.
>
> (There is no universally best election method. Different methods are good
> for different needs. That's why one can not determine the best method
> without knowing what the method is used for and in what kind of an
> environment.)
>
> > Pass/fail, in contrast, is completely unambiguous. Either a method
> passes or it doesn't, and if a method passes a criterion everywhere, then
> obviously it passes it "where it counts", no matter where that might be.)
>
> Yes, full comptibility is full compatibiliy everywhere, but using only
> on/off criteria does not give as accurate results as measuring criterion
> compatibility using some richer scale. For example some "black" results may
> be actually "white" in real life situations (i.e. vulnerable in theory but
> not in practice).
>
> All interesting methods fail at least one criterion that sounds important
> and that is also important in the sense that some bad violations of it are
> in some methods also very bad in practice. That however doesn't mean that
> all methods would be useless or bad. One needs a balanced approach to all
> criteria in the spirit of making the overall vulnerability of a method
> small. This may sometimes mean allowing minor vulnerabilities somewhere in
> order to 1) make some other vulnerabilities less serious, or to 2) make the
> positive properties of the method better (e.g. to pick the best winner
> instead of resorting to some less good alternative, maybe as a result of
> optimizing the strategy resistance of the method too far).
>
> Juho
>
>
>
>
>
>
> ---------- Forwarded message ----------
> From: David L Wetzell <wetzelld at gmail.com>
> To: EM <election-methods at lists.electorama.com>
> Cc:
> Date: Mon, 30 Jan 2012 11:57:29 -0600
> Subject: [EM] Which matters more: Getting/Figuring Out the Best
> Single-Winner Rule or Incorporating More Multi-Winner Rules ASAP in the US?
> is the relevant question and nested within it is whether or not the US's
> two-party dominated system can be saved without pushing for a more EU-style
> multi-party system.
> Cuz, even if X_EU >> X_2partystatusquo that does not mean X_EU*p_EU>
> X_2partyplus*P_2partyplus, whereas X_2partyplus is at least >
> X_2partystatusquo.
>
> This is at the heart over whether or not an approval-voting enhanced IRV,
> or IRV+ is suitable as an initial consensus single-winner rule to pave the
> way for more innovations and experimentation later.  Unlike with Approval
> Voting, IRV+ tends to support a 2partyplus system which is part of the
> reason why in the short-run at least P_IRV+>>P_Approval.
>
> A similar arg can be given for American forms of PR that also tend to
> support a 2partyplus system.
>
> I've argued here that your many args over the Xs are less important than
> the Ps.  One of the key args for this has been that given the specificity
> of the status quo system in the US, it seems the number of serious
> candidates is held down in our single-winner elections, or almost all of
> our elections and fewer serious candidates inevitably reduces the Xs among
> single-winner election rules.  I'd add that the inability of this listserve
> to come upon a favorite alternative to any brand of IRV indicates that Xs
> are also fuzzier than short-run Ps.  The clear-cut nature of short-run Ps
> make it a natural basis for rallying sincere electoral reformers, which
> will in turn tend to bolster the Ps of the pragmatically chosen initial
> main alternatives to FPTP for the US.
>
> dlw
>
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