[EM] Voter strategising ability

[robert bristow-johnson]

On 7/24/14 3:47 PM, Kristofer Munsterhjelm wrote:
> On 07/24/2014 06:11 AM, robert bristow-johnson wrote:
>
>> but the *data* doesn't give a rat's ass *how* it's counted or
>> tabulated.  can't we use the data from all ranked-choice elections
>> (which, in government, would be IRV or RCV or AV or STV or Hare) and see
>> how they would work out with Condorcet-compliant rules?  like we did for
>> Burlington 2009.  that was a 4-way election close enough that the
>> Plurality (of 1st choice votes) winner, the IRV winner, and the
>> Condorcet winner were three different candidates.  and yet there was
>> *no* cycle.  not even close to a cycle.
>
> Right, but if the data isn't from a Condorcet election, those who 
> think Condorcet is vulnerable can just claim that the voters would 
> adjust their strategy to the methods in question.

i don't see how you could strategize a ranked-ballot election decided by 
Condorcet any more than a ranked-ballot election decided by IRV.  in 
Burlington 2009, that election *could* have sent a message to the 
GOP-Prog-haters that insincerely forsaking their favorite candidate can 
prevent their least favorite from being elected.  but that's a lesson to 
take to the *next* election and they didn't really figure that out.  and 
that strategy would not have been necessary if it were Condorcet.  i 
don't see how realistically voters would game a Condorcet election.

> Because IRV is relatively hard to strategize,

simpler than Condorcet.

> they could claim the lack of obvious strategy in IRV as evidence of 
> this -- or if there *is* strategy, that the voters will strategize no 
> matter what,

they can *claim* it, but that doesn't mean there's a basis for the claim.

> and therefore the method needs to deter even otherwise implausible 
> strategy from the very beginning.
>
>> are there any other ranked-choice elections where media or research
>> could access the anonymous ballot data and see if there would have been
>> a cycle and then see how Shulze and Tideman and Minimax and Kemeny would
>> have been different?  i think we would virtually never see a cycle.  and
>> *more* than virtually, i think we would *never* see a cycle with more
>> than 3 in the Smith set.
>
> There are lots of polls. For instance, Green-Armytage used data from a 
> political barometer (with Range scores) as basis for one of his 
> strategy calculations. There are also a number of groups and 
> associations that use Condorcet methods (often Schulze, and often 
> related to Debian, which first started to use it); and many of these 
> make the votes public.
>
> I have mentioned Debian before, but I have also heard arguments 
> against it on the grounds that Debian voters are "obviously different 
> from politically polarized general voters" and so that piece of data 
> doesn't count.
>
> I also think San Francisco provides ballot data for their elections, 
> but I'm unsure of this. I also seem to recall that the general pattern 
> is that Plurality is pretty bad at electing the CW, IRV is somewhat 
> better,

has there been an IRV election, other than Burlington 2009, where the CW 
was not elected?

> and Condorcet (obviously) elects the CW when there is one.

-- 

r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."