[EM] To Martin re: bad consequences

[MIKE OSSIPOFF]

Martin quoted my reply selectively, and so I'd like to send my
entire reply here:


I'd said:

        It couldn't be, could it, that that's
because you don't have any examples in which those wv strategy "problems"
cause serious consequences?

Martin said:

Consequence One: People discover that the optimum strategy is to always
give a full ranking, even where you have no or very little preference


I replied:

Sorry, but Consequence One isn't valid. Perhaps Martin forgot that
that strategy of voting a full ranking even though one is indifferent
between some bottom candidates is a 0-info strategy. Public political
elections aren't 0-info elections.

If you expected that a certain candidate might be sincere CW, and
that order-reversal might be employed against him, then the
deterrent counterstrategy is to not rank anyone whom you like less
than him. The existence of this deterrent will deter offensive
order-reversal.

But even if it were a 0-info election (though it wouldn't be),
and a voter felt a temptation to increase his expectation slightly
by randomly ranking some bottom-end candidates, so what? Who is
wronged? That voter? He doesn't have to employ that strategy. A victim
of temptation?

Your claim that it will make him stay home because it's too much
work to randomly rank some equally-preferred bottom candidates
is more than a little silly. But evidently you're trying hard, and
you deserve credit for that.

Martin continued:

,
    and decide it's all too much effort. They don't turn up. Turnout drops.
The wrong candidate is elected.

Consequence Two: As noted, humans are *very* poor randomisers, even when
trying hard to be random we are only 20% random. When not trying, we're
about 2% random. The wrong candidate wins because of this, one who is
sincere-rated last by all of the electorate.

I replied:

Again, you're forgetting that you're talking about a 0-info strategy,
and that public political elections aren't 0-info. And again, who
is wronged because someone who is indifferent between some candidates
ranked them in an order that isn't random? Margins is much more
vulnerable to the voting of unfelt preferences than wv is.
For instance, show me how it violates majority rule or causes a
lesser-of-2-evils problem. Or any problem that someone has a right
to complain about. "No fair, my candidate lost because someone
ranked someone else over him when he really was indifferent between the
two!" :-) Oh you poor guy!

Martin continued:

Consequence Three: Even if they are good randomisers, there's a random
element. In small elections, that's a significant source of noise. The
wrong candidate is elected as a result.

I replied:

Martin sets himself up as the arbiter of who is the right or wrong
candidate to win.

But Margins doesn't elect the wrong candidate, does it, when it
dumps the sincere CW because mere truncation or easy order-reversal
has stolen the election :-)

Martin continued:


Example of consequence two:

A,B,C,D, in that order on the ballot paper.

Sincere Votes and votes under margins:
10 B>A=C=D
10 C>A=B=D
10 D>A=B=C

Actual Votes under wv:
10 B>A>C>D OR B>A>D>C OR B>A(>C=D)
10 C>A>B>D OR etc
10 D>A>B>C OR etc

Result: A is the wv condorcet winner, despite being hated by everyone.


I replied:

A is so much hated by everyone that they all consider him a 2nd choice
and rank him alone in 2nd place :-)


Martin continued:

    Margins would give a draw to B,C,D.

I replied:

In a real election, B,C, or D voters would estimate which of those
is the biggest rival, and try to him lose to the other 2 of {B,C,D}.
No, I haven't checked that out, because this example has just now
been posted, but at first glance it seems likely. That removes that
candidate from the tie, and improves your chance of your favorite
winning in the tie.


Martin continued:

Hence, winning-votes fails my newly invented Universally Despised
Candidate Criterion, which makes it even worse than IRV's failure of
Mike's Universally Unprefferred Candidate Criterion. Here A is hated,
and hated by *everyone*, yet still gets elected.

I replied:

"Hated by _everyone_", who consider A a sincere 2nd choice, and
rank A alone in 2nd place  :-)

Martin continued:

Serious enough for you?


I replied:

No, but I commend you for a serious, if silly, effort.

Mike Ossipoff


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