[EM] Kristofer: Reply re: ICT criterion-failures, continued

[Michael Ossipoff]

Kristofer:

You complied with two of my requests:

I'd asked for a precise definition of Clone-Independence, and you posted one.,

I'd asked for a failure-example, and you posted one.

But that wasn't all that I'd asked for, was it.

I'd also asked for an explanation of why that critrerion failure is an
acutal problem.

In other words, I'd asked you to show a clone problem for Approval,
Score, ICT or Symmetrical ICT.

You didn't do that.

Of course there isn't a clone problem for those four abovementioned methods.

In your ICT Clone-Independence failure example, half of the A
preferrers, when A2 is introduces as a clone of A, rank A2 in first
place, and demote A to 2nd place. But, you know, they don't have to do
that.

If they want to play it safe, in Approval, Score, ICT or Symmetrical
ICT, those voters can approve or top-rank _both_ A and A2. So doing,
they'd be no worse off than before A2 was introduced. Their
expectation, when approving or top-ranking both A and A2 would be
higher than it was before the introduction of A2. Especially if A2 is
so good that it almost tempts them to not approve or top-rank A. In
fact, it's the raising of their expectation by the introduction of A2
that creates that temptation.

The fact that A2 could be so good as to raise A-preferrers expectation
enough to make optimal a gamble for big improvement, approving or
top-ranking A2 but not A, can hardly be called a problem. As problems
go, it isn't a problem.

The A-preferrers needn't be any worse off than before, because they
can approve or top-rank both A and A2.

So much for ICT's "clone problem".

Now, maybe, in this special clone example, with Beatpath, the
A-preferrers have the luxury of being able to sincerely rank A2 over
A, without that being able to make the winner come from outside of
{A,A2}.

But, in typical situations, even including typical u/a elections, TUC
(of which Beatpath is a version) is the method in which you won't know
what to do. You won't know whether to top-rank acceptable candidates.
You'll have mutually-contradictory strategic needs in that regard, as
I've described before.

Approval's u/a strategy is simple and obvious: Approve (only) the acceptables.

ICT's top-end strategy is the same: Top-rank (only) the acceptables.

Bottom-end strategy is much less important, more of a nuisance that
needn't really be bothered with.

ICT shares TUC's bottom end u/a strategy: Try to rank the unacceptbles
in revese order of winnability.

Approval, meeting LNHe, has no such incentive. Just don't approve any
unacceptables.

Symmetrical ICT is about as easy as Approval at bottom-end too: Don't
rank unacceptables. Its Strong 0-info LNHe compliance is effectively
the same as LNHe compliance.

But it's at top-end that TUC most extremely shows itself to be a
strategic mess, in which you won't know what to do at all.

About Reversal-Symmetry:

You seem to be speaking of it as applying only to ranking methods.
That's ok for right now.

If the ranking set is the same, when all the rankiings are reversed,
the reason why those rankings should result in a tie between all the
alternatives is because:

Obviously for every X > Y in that ranking set, thre must be a Y > X as well.

Obviously, in a positional method, for any instance of X being rated
above Y by a certain distance, there must be an instance of Y being
rated over X by the same distance.

So of course there should be a tie between all of the alternatives--if
the method is a positional method or is based entirely on pairwise
order comparisons.

Advocates or usesrs of this criterion, then, seem to be saying that
all methods should be positional methods, or be based entirely on
pairwise order comparisons.

Why?

Sorry, but that requirement needs justifying.

ICT treats 1st place as more important than last place. Who is to say
it shouldn't? With unlimited rankings, expressed-favoriteness,
top-ranking, is something different from, and more than, the opposite
of last-place ranking. In general, top-end strategy is more important
than bottom-end stsrategy. That is reflected in ICT's count rules.

Users of Reversal Symmetry don't agree. But they can't legitimately
impose their personal preferences as a requirement for all methods.

My replies regarding your other ICT criterion-failures were already
adequate and complete, as already posted.

Mike Ossipoff