[EM] (no subject)

[MIKE OSSIPOFF]

Kevin--

I'd said:

>Of course if the C voters and B voters aren't sure which of {B,C} is the 
>CW, and neither wants to elect A, and neither wants to be had by the other, 
>then both the B voters and the C voters should rank B and C, in sincere 
>order of preference, applying ATLO immediately below their favorite.

You say:

That's an interesting approach. I wonder if it's monotonic?

I reply:

I don't know, do you know of a nonmonotonicity example?

Even if there were to tun out to be nonmonotonicity in the use of ATLO &/or 
AERLO, that wouldn't mean that it's a problem. For one thing, I'm interested 
in strategy problems only. For another thing, if it's difficult to find a 
nonmonotonicity example, then they aren't likely to occur. And the rarer 
they are, the less likely they could be exploited. Even in IRV, where the 
nonmonotonicity happens so easily, where the nonmonotonic examples are so 
easily written, it wouldn't be easy, and maybe wouldn't be feasible, to 
exploit it. I and others have long said that nonmonotonicity isn't IRV's big 
problem.

Anyway, AERLO & ATLO aren't part of the methods they're used with; they're 
options. So even if there turned out to be nonmonotonic situations when 
they're used, that's different from a method itself being nonmonotonic.

Of course it's much easier to find and post a criterion failure example than 
to show that there can't be one. Sometimes, when there isn't one, it might 
be impossible to show that there can't be one.

So, it's easy to say "Is that monotonic?", but it's more useful, though not 
always as easy, to post a nonmonotonicity example.

I'd said:

. But SD, SSD, BeatpathWinner/CSSD, MAM, and
>RP meet SDSC. And, with ATLO, those ballots that you list below wouldn't 
>happen, given the preferences that you listed above.

You replied by posting these ballots:

49 A
24 B
27 C>B (ATLO line between C and B)

I reply:

...and those ballots, too, wouldn't happen with the preference orderings 
that you listed. The B voters would know that there was nothing for them to 
gain by offensive truncation.

You continue:

Also interesting, this is a case where a method can satisfy SDSC while
failing votes-only Minimal Defense, according to which A mustn't be elected
on the above ballots.

I reply:

Yes, and that says something about votes-only Minimal Defense, doesn't it.

Would it be better for B to win with those ballots, including the ATLO line? 
If B could win with those ballots, there'd be the co-operation/defection 
dilemma--you know, the one that I said that ATLO gets rid of. You doubed 
that ATLO gets rid of it, I told how it does, and now you seem to want to 
not get rid of it, because that's what it means if B can win with those 
ballots.

Apparently votes-only Minimal Defense is a good criterion to fail.

When, to meet a criterion, it's necessary to keep something undesirable, 
like the co-operation/defection dilemma, that suggests that maybe your 
criteria isn't as valuable as you think it is.

Would you mind telling me again in what situations you believe that your 
votes-only Minimal Defense works better or gives a fairer or more acceptably 
right answer than SDSC does? Do you say that votes-only Minimal Defense 
doesn't apply to Plurality, or do you apply it to all methods and say that 
Plurality passes?

You continue:

It could be unpleasant for the C voters if, as it turns out, the B voters 
don't
prefer C to A. The voters have to be a little clever to use the ATLO.

I reply:

You questioned whether ATLO can get rid of the co-operation/defection 
dilemma in wv, and I told you how it can. When that situation exists, it 
doesn't take cleverness to recognize it.

For instance, when I still believed that Kucinich and Sharpton were 
progressives, I thought that they were the best candidates in the Democrat 
primary. What if the primary were by Approval. That would be the 
co-operation/defection example that James posted as an Approval bad-example. 
Others had previously used that as an Approval bad-example.

Now, would you recognize that situation (given the assumption that Kucinich 
& Sharpton are progressives) as a co-operation/defection dilemma for 
progressives? The Kucinich-preferrers and the Sharpton-preferrers presumably 
would all prefer either to some sleaze crook like Dean.

So no, it doesn't take cleverness to recognize that situation when it 
occurs.

But, in general, of course strategy often requires some knd of information, 
and the best use of that information. That isn't only true of wv with AERLO 
& ATLO, or wv without those things. It's been shown that all 
nonprobabilistic methods will sometimes give incentives for strategy. What's 
your best method proposal? Does it ever require any "cleverness" or strategy 
decisions? How does it do in that co-operation/defection dilemma? How minor 
do you claim that it's worst strategy problem is?

What if the B voters don't prefer C to A? Unless voters live in a vacuum, 
there's be public understanding about that, at least when, as always assumed 
in those examples, C & B are similar and clearly better to their advocates 
than A.

If B voters don't prefere C to A, and C voters prefer B to A. then 
truncation by B voters isn't defection, and there' so reason for the C 
voters to not rank B, or to use ATLO against B. Knowing that the B votes 
won't rank C, for sincere reasons rather than as offensive strategy, the C 
voters would want to get their best possible outcome by ranking B in 2nd 
place without ATLO.

I'm assuming of course that B isn't really repugnant or completely 
unacceptable to the C voters, that they don't believe that B isn't good 
enough to deserve a vote.


Mike Ossipoff

_________________________________________________________________
Express yourself instantly with MSN Messenger! Download today - it's FREE! 
http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/