[EM] Steve Eppley's Just-In-Time Withdrawal (JITW)

[Raph Frank]

On Tue, Jan 8, 2013 at 12:43 AM, Michael Ossipoff
<email9648742 at gmail.com> wrote:
> Here's Steve's proposed fix:
>
> After an election, any candidate can withdraw from the election, and
> call for a new count of the ballots, with his name deleted from all
> the ballots.
>
> I liked JITW, because it saves FBC-failing methods from their FBC failure.   .

Maybe.  You could end up with a "chicken" dilemma.

For example, if there are 3 candidates in a condorcet loop.  If either
of the 2 non-winners withdraws, then the other loser becomes the
winner.

In a L - C - R situation, if R wins, then if L or C withdraws to the
other one becomes winner.  (assuming R is not the condorect winner)

C with 5% of the first choice vote would have a hard time justifying
not withdrawing.  He could say that his supporters consider L + R
equally bad, so there is no benefit to his supporters in not
withdrawing.

That would probably lose him the 2.5% of the vote that was L leaning,
in the next election.

> In group-reply e-mail, Steve and I proposed JITW IRV to IRVists. They
> rejected it, claiming that it was completely unacceptable to let a
> candidate withdraw. They seemed to feel that a candidate's withdrawal,
> in JITW, would somehow be a betrayal to the people who'd voted for
> that candidate.

It would increase the complexity of IRV.  Complexity is regularly used
as an all-purpose objection to most non-plurality voting system.

Would you be intending multiple passes, or a single withdrawal round?

So,

- IRV count
- one or more candidates withdraw
- final IRV count

or looping, with a full recount being triggered by each additional withdrawal?

With 1 withdrawal stage, it would possibly get past the complexity
objection (esp if IRV was supported in the first place).

However, I am not entirely convinced that candidates would put their
voters first in such a situation.  Better to play chicken and probably
lose than withdraw and definitely lose.

This is also a problem with Asset voting.

Maybe the withdrawal decision could be taken by someone other than the
candidate themselves.

Also, if a threshold was added then you could sometimes have only one round.

IRV count (transfers below the threshold ignored)
- if the winner gets > 50% of the ballots cast, winner wins without a
second stage

Withdrawal stage

IRV count 2 (transfers below threshold included)