[EM] Further comments to Kristofer's MJ posting

[MIKE OSSIPOFF]

Kristofer:

A few more comments to the same posting that I replied to yesterday. 
Additional answers to the same statements:

I'd said:

> What about Approval? It's simpler. Simpler to define, implement and
> vote. And supplementable by the conditionality options that I've
> described, to get rid of the co-operation/defection problem.

You replied:

If I'm to use ratings, I would prefer something that doesn't require 
that I fit my ballot to the polls.

[endquote]

What you want doesn't exist. No nonprobabilistic ballots-only method
is free of need of strategy based on other people's preferences and'
predicted voting.

You continued:

 To do the frontrunner plus strategy 
in Approval, you have to know who the frontrunners are, and that data 
itself might be inaccurate due to strategy.

[endquote]

That's something that I sufficiently answered yesterday, pointing
out that "frontrunner-plus" isn't the only non-u/a, non-0-info
Approval strategy. It depends on what you know of have a feel for.

You continued:

In a sense, Approval solves the strategy problem by simply making 
strategy part of its usual working...By consistently acting like the worst came to pass, you get 
rid of any temptation to *go* to that worst case, because you're already 
there.

[endquote]

Other methods are already there too, but their advocates just don't know it.

The complexity of some or most methods allows their proponents to hide from
their strategic facts, and believe what they want to. Approval gets criticized for
its strategy because that strategy is transparently obvious, because Approval doesn't
obfuscate it. Obfuscation by complicated methods allows their proponents to pretend
that they don't share Approval's strategy need, or have a worse one.

You continued:

Aren't your conditional methods ranked methods rather than rated ones? 

[endquote]

Sure, if you consider Approval to be a ranked method rather than a rated one.
As I said, I consider that a questionable and blurred distinction.

AOC is conditional Approval. So are MMT and GMAT. MMT, GMAT have built-in, not-optional
conditionality-by-mutuality. AOC can have fully optional conditionality by mutuality &/or
top-count. With AOC, MMT or GMAT, the option of conditionality-by-top-count can be added,
to be offered along with that method's conditionality-by-mutuality, in the same election.

You continued:

The criteria I mentioned aren't applicable to ranked methods because 
ranked methods can't pass IIA 

[endquote]

Approval passes IIA.

I haven't checked AOC, MMT, GMAT, MTAOC, MCAOC AOCBucklin and ACBucklin for IIA compliance.

MJ will soon become Approval. A complicated, elaborately-&-expensively-implemented
Approval. 

I realize that you think that few people will strategize, and that
the strategizers won't be numerous enough to make a difference. I'll get to that
later when you make those statements in this posting.

> Your reply regarding MJ seemed basically to be saying that maybe you
> won't regret voting sincerely in MJ. That's great if you like "maybe".
>
> When you say that some will rate sincerely, you're moving the topic to
> psychology. And I like the way you guys like to theorize about how people
> would vote, while declining to find out what voting is like in the
> various proposed methods, via a poll.

You continued:

We have the Laraki & Balinski MJ poll. The voters didn't strategize 
there, though you could of course say that's because they didn't see the 
implications of the system yet. To take that into account, you'd have to 
poll the same people many times -- enough that they may sit down and 
think "you know what, if I do this, I can only benefit...". I'm not sure 
how you would do that. Perhaps Quinn can do it in his Turk polls.

[endquote]


People tend to want to do what's in their best interest. Experience shows that
voters here will vote strategically, even to the point of drastic favorite-burial,
because they believe it to be strategically in their best interest. More later when
you make your comments about that.


I'd said:

 > But maybe you're right. Maybe in MJ some would rate sincerely and some
> would, instead, vote in their best interest.
>
> Whether that is good or bad depends on whether the suckers are your
> co-factionalists or mine.

You replied:

In MJ, defectors have no effect unless there are enough of them or 
they're lucky, since the median is a robust estimator and 
Approval-strategy basically involves adding outliers to influence the 
estimator.

[endquote]

No one denies that the median is a robust estimator, where outliers' effect
is independent of how far they "outlie".

It amounts to Approval. If you rate someone above where hir median would otherwise
be, then you're raising hir median by the same amount, regardless of how far you rate
hir above that median. 

If you rate someone top or bottom, you _reliably_ raise or lower hir median. 

If you rate x top and y bottom, then you _reliably_ help x against y.

The more closely you rate two candidates, the less likely you are to be helping
one against the other.

...just as, in RV, the more closely you rate 2 candidates, the less you help one
against the other. The difference is that, with MJ, it's about the probability of
helping one against the other. You don't know if you are at all.

Say my sincere ratings are:

x: 100
y: 90

(other candidates considerably lower)

Your sincere ratings are:

y: 100
x: 90

(other candidates considerably lower)

x and y are similar, but different enough to be supported by
different factions.

This situation is hardly unusual.

My ratings:

x: 100
y: 0

Your ratings:

y: 100
x: 90

Guess which of those two is more likely to win.

To both of us, x and y could be called "favorites". Different people
have different favorites. Therefore, the medians of x and y are likely
to be lower than your ratings of them--They're not as favorite to everyone
as they are to you.

Therefore, you're rating x and y above their otherwise-medians. Therefore
you're raising both of their medians.

You're raising my candidate's median. I'm lowering your candidate's median.

And that situation, as I said, is hardly unusual.

Of course, instead of speaking of just two voters, we should speak of two factions
of equal size. Your faction will be had--will lose due to its sincere rating.

Mike Ossipoff




 		 	   		  
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