[EM] Re: Condorcet's strategy problem

MIKE OSSIPOFF nkklrp at hotmail.com
Fri Sep 16 21:52:11 PDT 2005


You wrote:

That's my central objection to Approval when compared to Schulze(wv) and
other Condorcet-compliant methods.  In the vast majority of cases, a
simple sincere ranking works in Schulze(wv).  It's what I can do, it's
what I can tell others to do.

I reply:

Sure. Because of SFC, GSFC, Condorcet's Criterion & the Smith Criterion.

As I said in a different discussion, what I like about wv is the automatic 
compromise that pairwise-count provides, and which is especially protected 
by wv (including BeatpathWinner).

That compromse is the CW or the sincere Smith set. It's protected by SFC, 
GSFC, Condorcet's Criterion, and the Smith Criterion.

That's why I suggest BeatpathWinner or CSSD for organizations and 

But Condorcet has two problems with the public: 1) It doesn't have RV's 
familiarity and obviousness; and 2) It doesn't meet FBC, so you can't 
emphatically assure someone that they have absolutely no reason to vote 
someone over their favorite

You continued:

With Approval, the strategy has a lot of caveats in what could become
relatively common situations.

I reply:

True. With Plurality there will always be two frontrunners (probably as an 
artifact of Plurality), but with Approval, one might well have to deal with 
situations without two clear frontrunners. So yes, with Approval, strategies 
other than Best Frontrunner are likely to be sometimes needed.

What can I say? Ideally we'd like a method that the public would immediately 
embrace, and in which no one would ever have any incentive to vote someone 
equal to their favorite. Regrettably, strategy is unavoidable. It's a 
question of what kind of defensive strategies we want people to need.

Yes, the usual advice to members of the public, with Approval, is to vote 
for the person you'd vote for in Plurality, and for everyone whom you like 
better. But when Approval gets rid of the artificial 2-party system, 
Best-Frontrunner won't be applicable, as I was saying. So we'll have to 
change our advice to Better-Than-Expectation, or Threat/Promise, or 
something. But those aren't so compliated, and a voter _won't_ need a whole 
set of different strategies for different situations. One will do, if it 
isn't Best-Frontrunner.

Sure, if it's 0-info, then voters could just vote for the above-mean 
candidates. But that's just a special case of Better-Than-Expectation. Sure, 
if it's Acceptable/Unacceptable, we have the especially simple strategy of 
voting (only) for the acceptables. But, for one thing, that's so simple and 
obvious that you can't call it a complication. Besides, it, too, is just a 
special case of strategies such as Better-Than-Expectation. If all the 
merit-difference is between, not among, the two sets, then even the 
slightest possibility that it isn't a sure thing that one particular set 
will win will put the expectation between the two sets' merits.

So, Approval strategy won't be as complicated as you portray it. It won't 
require telling people a whole set of strategies for different situations. 
Yes, Best-Frontrunner will no longer apply when Approval busts the phoney 
2-party system wide open, but one of the more general Approval strategies 
will work fine.

You could point to the co-operation/defection dilemma that is often put 
forth as Approval's bad-example. But wv (without ATLO) is subject to that 
problem too. WV, with ATLO, gets rid of the problem easily, something that 
isn't possible in Approval. But it isn't as if that is one of many 
situations for which Approval needs many strategies. If there's a 
co-operation/defection dilemma, then there isn't really a strategy for it. 
One is on one's own, to follow the ethical and psychological geography of 
the situation. Are the supporters of your candidate more principled? Is your 
candidate more principled? Then make it clear that your faction isn't going 
to vote for both candidates. Or is the other candidate practically just as 
good, with sincere supporters? Then why not vote for both?
It isn't a matter of strategy, and so it doesn't justify the claim that 
Approval has lots of needed strategies.

Elsewhere I've talked about why the co-operation/defection dilemma isn't as 
serious a problem as it's sometimes portrayed. It isn't a majority-rule 
violation, and defectors will regret defection, in subsquent elections. And, 
in those subsequent elections, there won't be any more 
co-operation/defection dilemma, because co-operation with that faction will 
have been shown to be a mistake. Both factions will know that.

I'd asked:

    Why is it stupid to do whatever it takes to maximize the probability 
that an acceptable candidate will win, if the merit difference among the 
acceptables, and among the unacceptables, are negligible compared to the 
merit difference between the acceptables and the unacceptables. Under those 
conditions, what matters is that an acceptable wins, not _which_ acceptable 
wins. So you rank them in an order that maximizes the probability that one 
of them will win. That probably won't be sincere order.

For people whose sincere first choice has a shot at winning, it is.

I reply:

Not really. Say it's an acceptable/unacceptable situation, and that your 1st 
choice has a nonzero probability of winning. So do the unacceptable 
candidates. In fact they have a very good probability of winning. You can 
vote your favorite candidate in 1st place, even though the merit difference 
between your acceptable candidates is negligible, in comparison to the 
acceptable-unacceptabale difference, or you can demote him when it increases 
the probability that an acceptable will win.

That being so, and if you're voting competently, you'll demote your 

What you can correctly say is that if the election is not an 
acceptable/unacceptable situation, then maybe sincere ranking is best. I 
have never denied that.

You wrote:

I  suspect that the vast majority of people will want one of the
frontrunners to win.  That's what makes them "frontrunners", after all.

I reply:

I don't know how _vast_ a majority it takes to make 2 candidates the 
frontrunners, but sure, they must be popular. And if one of the frontrunners 
is your favorite, then I agree that you should vote for  him (and not for 
the other frontrunner). But that doesn't relate to the question of whether 
you should be faithful to your sincere preference-ordering in an 
acceptable/unacceptable situation.

You continued:

Even if your favorite doesn't have a shot, in most situations, voting
for your favorite won't hurt.

I reply:

Yes, voting for your favorite in Approval will never hurt. And, in Condorcet 
wv, it's only in rare, contrived situations that you could regret not 
burying your favorite. I don't deny that either. But that doesn't contradict 
the statements that I've made.

I don't know how you've been voting. If you've been voting for Kerry, Gore, 
etc., but wouldn't insincerely rank them 1st in BeatpathWinner, than that 
proves that not every such voter would do that. Sure that 's a good thing. 
But some LO2E progressives would bury Nader to rank Kerry 1st. As I said, 
I've observed it.

You continued:

It's certainly not nearly as risky to
vote sincerely for your favorite in Schulze(wv) than it is in Plurality.

I reply:

Yes, that's for sure. The threat that that will let the greater-evil win 
isn't as great when it only happens in rare examples. Surely there will be 
many who won't be compelled by that threat. And equally surely there will be 
some who will be. No one can say how many. Maybe  what I've observed of LO2E 
progressive Condorcet voting would actually be rare, and has unduly scared 
me. Who knows? But one can only go by what one has observed.

You continued:

Since I've personally chosen to "waste my vote" on a protest vote in the
past under plurality (in at least one dangerously close contest, no

I reply:

Salutations. Keep doing it. If you really want to waste your vote, you'll 
vote for someone you don't really like, someone whose policies and ethics 
are repugant to you. Someone like Kerry or Dean.

You continued:

, I don't anticipate that the much reduced risk in Schulze(wv)
would be much of a deterrent for me.

I reply:

Good enough, and maybe many others would feel that way. But what's wrong 
with the FBC-complying rank methods? ...Aside from the fact that no rank 
method has RV's familiarity or simplicity?

I'd said:

My objection to people needing to [reverse order] is not that it isn't safe 
enough, or that it isn't as safe as Approval. My objection to it is that 
that voter is falsely saying that s/he likes Kerrry better than Nader. That 
voter is concealing their liking for Nader. That voter, in Condorcet, but 
not in Approval, is failing to show full support for Nader. That's what I 
object to in methods that fail FBC.

You replied:

It's a matter of degrees.  Under Approval, the voter is saying that both
Kerry and Nader are equally acceptable.  For that matter, they may even
have to say McCain or Giuliani is just as acceptable if it means beating

I reply:

Yes, they might do that. That could be good Approval strategy, given those 
voters' major mis-evaluations  of candidate merit, and their complete 
demoralization and resignation.

You continue:

While that may not seem as bad as saying that Kerry is better than
Nader, in my mind, it's only a question of degree of insincerity.

I reply:

Of course. I haven't denied that either. But do you want a higher degree of 
insincerity, or a lower degree of insincerity? Besides, there's a very big 
difference between the results of those two levels of insincerity. For one 
thing, when the defensive strategy involves voting someone over your 
favorite, it only takes half as many mistaken compromisers to give away an 
election, as compared to Approval or RV.

And, when voters are burying their favorite, they're completely concealing 
their support for him/her. In Approval or RV, they'll still give full 
support to their favorite. No, your LO2E compromisers won't express that 
they like Nader better than McCain. But they'll show that at least they're 
supporting Nader as much as anyone. That allows Nader to maybe outpoll the 
Republican, giving progressives information about whether or not they really 
need the Democrat. That doesn't happen when they've completely buried their 

So there's a big difference between voting someone equal to your favorite, 
and voting someone overe your favorite.

    [Rob continues]:
>We'll have to agree to disagree, because [absolute avoidance of favorite 
>betrayal] is not my goal.

[Mike replies:]
Ok, but when people are afraid to show full support for their favorite, 
"Democracy" becomes a joke.

You reply:

"Full support" means being able to express which candidate I
like /better/ than any other.

I reply:

That's a semantics quibble. If you give Nader the highest possible rating, 
that could be called full support, even if you give that full support to 
McCain too. If you don't call that full support, then maybe I should find 
another word for what I mean. Maybe just "highest rating".

But sure, the McCain & Nader Approval vote doesn't fully express how much 
you prefer Nader. But it does so better than the McCain>Nader>Cheney 
Condorcet ballot. As you said, it's a matter of degree.

You continued:

As I've said, absolute avoidance of favorite betrayal is not a goal of
mine.  It /is/ an important means, so it's only with great caution that
I'd recommend a system that doesn't meet FBC.  Given what I've seen, the
FBC problem in Schulze(wv) doesn't warrant throwing the baby out with
the bathwater.

I reply:

It's only for public political elections that I wouldn't suggest Condorcet, 
because I'd insist on an FBC-complying method. But there's nothing wrong 
with disagreeing on that. You said it's a matter of agreeing to disagree, 
and on that I agree.

You also suggested the origin of the disagreement: We have different 
perceptions of how many LO2E progressives are likely to bury their favorite 
in Condorcet. That's probabliy explained largely by different experience. 
Maybe I overvalue the observation of one LO2E progressive voting in an 
Internet Condorcet poll. And maybe many LO2E progressives don't consider it 
an acceptable/unacceptable situation (with Democrats acceptable), feeling 
instead that, as bad as the Republicans are, there's significant difference 
among the Democrats and Nader. But, even so, if the voter believes that 
Nader has virtually zero chance of winning, s/he might believe that the 
possiblie benefit of ranking Democrat in 1st place is greater than the 
benefit of ranking Nader 1st, when considering their low estimate of Nader's 
win-probabilty. That probably explains the favorite-burial that I observed. 
You can't say that others won't do that.

Anyway, it's a matter of one's estimate of how many LO2E progressives will 
do that. We just have different impressionis of how many will do that. But 
if you want a rank method, and wouldn't support Range Voting or Approval, 
then why not consider the FBC-complying rank methods for public political 
elections. Some of them have definitions that are quite brief and natually 
and obviously motivated and justified.

Mike Ossipoff

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