[EM] Approval reducing to Plurality

[Kevin Venzke]

Hi Juho,

--- En date de : Dim 29.8.10, Juho <juho4880 at yahoo.co.uk> a écrit :
> De: Juho <juho4880 at yahoo.co.uk>
> Objet: Re: [EM] Approval reducing to Plurality
> À: "Election Methods" <election-methods at electorama.com>
> Date: Dimanche 29 août 2010, 16h59
> Yes, polls that are arranged before
> the actual election is an interesting approach for Approval
> since Approval may fail badly if there are more than two
> potential winners in the actual election. Particularly this
> could offer some help in the Burr dilemma set-up where e.g.
> the right wing has two equally strong candidates. 
> (Approval may perform better when there are three candidates
> tied in a triangle.)

Yes I don't think the Burr dilemma scenario is one that Approval is likely
to choke on in practice. I think polls or parties will work it out to
eliminate the dilemma, in the same way and for the same reasons that 
intraparty contests don't tend to survive up to election day in Plurality
elections. There is so little possible gain, and everything to lose.

If a triangle type of situation makes it to election day (which seems more
plausible to me, if there's a cycle or something) I do agree that
Approval will probably handle it better than a Burr dilemma, but only by
a little bit... Resolving the election somewhat arbitrarily as opposed
to having good win odds for the worst candidate.

> The problems are however not quite over yet. One potential
> problem is strategic answers in the polls. It would make
> strategic sense to R1 supporters to start the polls by not
> showing any support to R2. That could make R1 look better
> than R2. And that could lead to a game with the polls, both
> groups trying to present themselves as the stronger group.

Yes but by the end of the day I just don't think that will be present.
Unless nobody actually cares about winning the race for the team, at
some point before the election there needs to be a decision. If this is
really a problem I can imagine having primaries etc.

Really nothing new should be revealed on election day. If the outcome
would be "Burr dilemma kills one side," that's exactly what the polls
should be saying before the race. If they want to avoid that they need
to try harder to consolidate. (I don't see rank ballot methods as much
better here, incidentally. Even with marginal improvements in ability to
handle the situation, there is still very little to gain compared to what
can be lost.)

There is the thought that Approval forces the voter to strategize...
But in practice all the strategy (if you can recognize it as such) 
should be in what happens with the polls and whatever affects the polls.
On election day the strategic voter probably only has one meaningful
decision to make, and it's a binary one.

The downside for Approval is what happens when assumptions about quality
of polling information and the ability of polls to reach equilibrium
don't hold. I.e., when voters are unable to play the game effectively.

Kevin Venzke