[EM] Cardinal Pairwise

[MIKE OSSIPOFF]

James--

Yoiu wrote:

	I doubt that ATLO and AERLO will be as effectively and easily
strategy-resistant as cardinal pairwise

I reply:

Fair enough, stating a first impression, but it´s also fair to ask you why 
you doubt that AERLO & ATLO will be as effective and easily 
strategy-resistant as Cardinal Pairwise.

(Yes, the official style is to not capitalize names of voting systems and 
criteria, but I capitalize them for clarity).

You continued:

, but I'd be open to further
discussion on the matter.

I reply:

Well, I´m just asking what gives you the impression that you expressed 
above.

You continued:

I ask that you please read the latest version of
my cardinal pairwise paper before engaging me in discussion about the
method's counter-strategic properties, because the paper goes into great
detail on the topic.

I reply:

I won´t presume to comment on what you say in the paper unless I´ve read it. 
I haven´t checked the paper yet. Now I´m commenting only on what you said, 
quoted above.

You continued:

	So, rather than asking whether cardinal pairwise provides the same
resistance to strategy as AERLO and ATLO, I'd like to ask whether AERLO
and ATLO provide the same resistance as cardinal pairwise.

I reply:

I´m not quite sure that I understand the difference between those two 
questions.

But, so far as I´ve noticed so far, the answer to both questions is "Yes".

But, as I´ve often said here, emphasis on "resistance" to strategyi is 
barking up the wrong tree. Is Plurality resistant to strategy? Are 
Plurality´s problems the result of lack of resistance to strategy? How about 
IRV?

I suggest that the problem isn´t lack of "resistance" to strategy, but 
rather the need for drastic defensive strategy. For instance, that´s the 
problem of Plurality & IRV, and of any method that has a strategy problem. 
To the small extent that Condorcet is susceptible to offensive strategy, 
that only causes a problem insofar as it creates a defensive strategy need.

You continued:

Also, I believe
that cardinal pairwise achieves many of its counterstrategic benefits
without any need for conscious counterstrategizing by the voters.

I reply:

Of course; that´s what makes Condorcet such a good method. And its 
enhancements, such as CP, AERLO, ATLO, and various others, improve that 
benefit.

You continued:

Lots of
voters giving Bush a very low rating and Kerry a very high rating makes it
very hard to overrule a Kerry>Bush defeat, but the voters don't all need
to understand majority rule cycles, or anticipate a particular strategic
incursion, in order to guard against an incursion that attempts to
overrule the defeat. The neat thing about cardinal pairwise is that rating
the candidates intuitively is usually a good protection against strategy.
AERLO and ATLO don't have this benefit, because the concept of truncation
lines and equal ranking lines is never going to be as intuitive to voters
as ranking the candidates on a scale from 0 to 100.

I reply:

Sure, the benefits of AERLO & ATLO _might_ be gotten by merely voting as one 
feels (if one feels like voting in a way that happens to be the 
strategically necessary way), with CP. On the other hand, however, there´s 
nothing complicated about intending to give fullest protection to a set of 
candidates, as AERLO & ATLO offer. Then it´s a matter of placing a line, 
rather than strategically, often insincerely, manipulating one´s cardinal 
ratings in CP.

So I´d say that both approaches have something that can be said for them. 
I´m not criticizing CP.

You continued:

	However, in the medium-long term, there is still a question of whether
ordinary winning votes is a good idea for major offices, i.e. president,
governor. I'm not sure that either of us want to go into this issue again
(we've both probably expressed most of our arguments already, and I
remember that we reached a frustrating deadlock on the issue in May of
this year)

I reply:

Well, several of us told you why Condorcet wv won´t have a strategy problem. 
Every suggestion that you made about a Condorcet strategy problem was 
answered by me and others.

You continued:

, but my feeling is that the burying strategy

I reply:

What do you mean by "burying strategy"? Insincerely voting someone lower? I 
assume that you´re referring to an offensive strategy, but burying is the 
defensive strategy in Plurality and IRV. One could express the distincition 
by saying "oiffensive burying". Then one would be using "burying" as a 
synonym for the previously long-used term "order-reversal". Is that what 
you´re doing? I´m just trying to clarify the meaning.

You continued:

...might be too big
of a problem in unenhanced WV to use it on this scale.

I reply:

Well, as I said, all of your concerns about that were thoroughly answered on 
EM by me and by others.

You continued:

Maybe we can agree
to disagree on that one

I reply:

Of course. But when we make statements, we can fairly be asked to justify 
them. And when our claims are answered, then the answers should be answered 
before the claims are re-stated.

You continued:

, and wait until we get more empirical evidence
from Condorcet methods used on a smaller scale.

I reply:

Condorcet has been used on a small scale in many polls, here and elsewhere 
on the Internet. Condorcet has been in use in organizations, and, from what 
I´ve heard, the results have been very satisfactory.

In any case, the only concern that could make someone hesitate to replace 
Plurality with Condorcet, Approval, or CR would be a concern that those 
methods could turn out to be worse than Plurality. Do you really believe 
that´s possible. If so, could you tell what gives you that concern, and give 
a scenario description and an example to explain that concern?

I claim that Approval, CR, and Condorcet can´t be worse than Plurality, and 
I´ve told of a number of ways in which they´d be better.

Yes, wv and Cardinal Pairwise fail Participation and  Consistency, while 
Plurality passes those criteria. But, as I so often say, one must choose 
which criteria seem important. If yoiu want Participation and Consistency, 
and major strategy improvment over Plurality, then choose Approval or CR.

You continued:


	I've been toying with the idea that Condorcet completed by IRV (choosing
from the minimal dominant set) might be slightly more acceptable from this
standpoint, but that has problems too, of course

I reply:

That´s an understatement. It doesn´t gain much other than the Smith 
Criterion (if, by minimal dominent set you mean the Smith set). The Smith 
criterion is easy for a rank method to meet. If you want a rank method, then 
be ambitious enough to ask for more than the Smith Criterion.




... I guess if that one
turned out to be okay, I would imagine the following progression for
single winner elections:

You continued:

1. plurality or runoffs
2. equal-rankings IRV
3. minimal dominant set completed by IRV.
4. cardinal pairwise??

	I don't know; it seems like something's still missing. What do you think?

I reply:

Well, we´ve already got Plurality and Runoffs, so hopefully we could soon be 
out of stage 1.

For #3, why not use ERIRV instead of IRV to choose from the minimal dominant 
set (Smith set?)?

Beggars can´t be choosers, and I´d be glad to start that progression, going 
to step two. That´s one difference between us: We Condorcetists and 
Approvalists aren´t critical of CP, but you´re always critical of Approval & 
Condorcet, claiming that they won´t be good enough, and not answering the 
answers to your concerns about them, but not letting that stop you from 
repeating the concerns.

But why progress in that way? ERIRV is an IRV mitigation compromise, but 
IRVists won´t accept such a compromise. So why propose ERIRV instead of 
Condorcet? When Condorcet has ATLO, it passes your co-operation/defection 
test, and has ERIRV dominated in terms of meaningful criteria.
If you object that ATLO is an ehancement that would have to be asked for in 
addition to Condorcet, then I remind you that equal rankings is an 
enhancement that would have to be asked for in addition to IRV.

>AERLO & ATLO are transparently purposeful & simple.

You wrote:

With AERLO and
ATLO, it seems that it might be a bit hard to use them without
understanding a whole lot about cycles and the burying strategy, or being
instructed by a party boss.


I reply:

It doesn´t seem so to me, because it would be enough for voters to 
understand that AERLO & ATLO can be used to give fullest protection to a 
favored set of candidates.


>CP
>requires strategic extreme point assignments.

You wrote:


	In what sense does it require them?

I reply:

To achieve the benefits of AERLO & ATLO, correct?

You continued:

Don't forget about the maximizing in
scale provision, which automatically rates your favorite candidate in the
minimal dominant set at 100, your least favorite in the minimal dominant
set at 0, and expands the gaps between the remaining candidates in the MDS
in proportion. (e.g. 50, 20, 10 becomes 100, 25, 0.)

I reply:

That would help, but wouldn´t guarantee the benefits without strategic 
extreme ratings.

You continued:

I'm not convinced
that a non-extreme set of ratings is always a mistake, strategically.

I reply:

In CR, it could make sense to give an intermediate rating to someone if you 
can´t decide whether to give them maximum or minimum points. In CP, I´m not 
saying it´s a mistake to not use extreme ratings, but merely asking if small 
ratings differences confer the benefits of AERLO & ATLO.

I´d said:

>AERLO, it seems to me is the more useful,
>and maybe, for simplicity, it should be the one
>recommended for general purpose. ATLO gets rid of the
>co-operation/defection dilemma that you described.

You replied:

	Which one? I thought that was a problem in approval, not WV... perhaps
you can refresh my memory.

I reply:

I told how, with offensive order-reversal, the problem could exist in 
Condorcet too. But I also told why it isn´t a serious problem. And, as I 
said, ATLO gets rid of the problem in Condorcet.

You continued:

The main counterstrategic advantages are
summarized in the cardinal pairwise paper. And those advantages do not
require extreme ratings.

I reply:

Ok, and for those advantages it would be necessary to read the paper. I 
don´t get much time on the computer, but I´ll check out the paper, first in 
its short version. Which of those links is to the short version?

But EM is intended as a place to make and support claims about method 
advantages. There´s no reason to not say here what the advantages are. And 
if you´re saying that those advantages are the ones that allegedly make CP 
strategically better than wv with AERLO & ATLO, then especially it would be 
good to give the reasons for that statement at the same place where you make 
the statement--on EM.

Mike Ossipoff

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