[EM] Strategy clarification re: Condorcet-IRV hybrids

[Michael Ossipoff]

I don't mean to say that, with those methods, members of a mutual
majority (MM) don't have any strategy incentive. There would be some
Condorcet strategy incentives.

If it looks as if IRV would eliminate the CW, then the favored wing
would have some incentive to use Condorcet offensive strategy against
the CW, to produce a cycle rather than a CW. Then, when the count goes
to IRV, the CW gets eliminated, and hir votes are transferred to the
favored wing, because that's the CW-preferrers' 2nd ranked choicee on
their ballots.

That could cause the elections to effectively devolve to
Condorcet-strategy elections.

But it would backfire if the favored wing got eliminated first. Then
their offensive strategy would elect the opposite wing.

Additionally, in the next election, that favored wing would likely be
the disfavored wing.

Additionally, that offensive strategy could only work if its victims
were trying help the perpetrators. How low is that? How likely does it
sound--especially considering the effect on the mutual majority?

For those reasons I don't consider it a problem.

But couldn't those arguments be used to defend Condorcet against
criticism of its offensive strategy possibilities?  Sure, and I've
used them. But the only offensive strategy that I consider a problem
of Condorcet is its chicken dilemma defection. The Condorcet-IRV
hybrids don't have a chicken dilemma.

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I'll refer collectively to Approval, and the strategically-similar
methods Score, ICT and Symmetrical ICT, as "Approval etc." or
"Approval&c".

Under current conditions, as opposed to Green scenario conditions,
Approval&c is the only class of voting systems that I recommend.

When I said that the hybrids are my favorite methods for the Green
scenario, I didn't mean to imply that there is a definite and obvious
choice. All methods have some sort of disadvantage or drawback.

In the Green scenario, that's true of IRV, the Condorcet-IRV hybrids,
and Approval&c.

I emphasize that all of these methods, including IRV would be
excellent for the Green scenario, despite their drawbacks.

IRV's drawback is that it imposes a favorite-burial incentive on the
disfavored wing. And it could displease CW-preferrers for their CW to
be eliminated. That could add up to a displeased majority that would
have sufficient numbers to throw IRV out, as in Burllington.

The Condorcet-IRV hybrids' drawback is the Condorcet offensive
strategy, but I've told why I don't consider it a problem.
Nevertheless, it means that the hybrids' success in use would depend
on trust and co-operation to some degree. I feel that it's to a
reasonable degree.

Approval&c's drawback in the Green scenario is just that it doesn't
have the other methods' automatic guaranteed election of a
mutual-majority-preferred candidate, and CD compliance, and the
strategy-free-ness that goes with those properties. It isn't that
there's anything wrong with Approval&c, or that it has a problem. It's
just that it doesn't being the tremendous strategic benefit of IRV and
the hybrids.

Michael Ossipoff