[EM] Proportional election method needed for the Czech Green party - Council elections

[Juho]

On Apr 28, 2010, at 6:37 PM, Jameson Quinn wrote:

> 2010/4/28 Raph Frank <raphfrk at gmail.com>
> On Wed, Apr 28, 2010 at 4:05 PM, Juho <juho4880 at yahoo.co.uk> wrote:
> > Do you mean that voters would concentrate on the first rankings and
> > strongest candidates? The used method should be such that this  
> kind of
> > behaviour will not be rational.
>
> Yes.  If the order of election matters, then your first rank is
> effectively for the president's position .. and it is a plurality
> election.
>
>
> Minor note: I proposed using order-of-election for vice president,  
> not for president.
>
> How about this: Elect the council with STV. Elect the president from  
> the council with Condorcet. Elect a two-member subset of that  
> council with PR-STV. Any members of that two-member council who  
> aren't the president are vice presidents.
>
> It gives a variable number of vice presidents. However, it seems  
> like a very fair all-around system, and needs no innovative new  
> methods.

If one uses the same votes in all three elections or in the latter two  
then the result could be quite proportional and quite free of  
strategic incentives. This method doesn't have the burden of keeping  
the president included in the elected "P+VPs" set (that is an  
"innovative new method"). But as a result the number of VPs may vary.  
If the president is not included in the VP set then the president is  
probably a compromise candidate from a small grouping. That causes  
some distortion in proportionality of the P+VPs set, but on the other  
hand I understood that there is also a strong interest to elect a  
centrist president and therefore this solution may be preferred to  
full proportionality. (Also the method where the president was forced  
to be included in the (fixed size) P+VPs set has this property.) We  
may thus not want full proportionality in the P+VPs set if we can find  
a good president "outside of the few leading groupings".

>
> Or, if you elected a 3-member subset, I suspect it would be very  
> rare that the president was not in that subset. If she wasn't, and  
> if 3 VPs were too many, you could then repeat the STV to choose two  
> of those 3, or let the board elect 2, or let the president pick 2,  
> or eliminate the Condorcet loser among those 3.

We are now sliding back to the world of "innovative new methods". I  
think none of the solutions is perfect (the first one is maybe the  
best of them). But if one wants an exact number of VPs then something  
must be done to reduce their number by one (or add by one). One more  
approach would be to use STV to pick either two of all the candidates  
depending on if the president is included in the set of three or not  
(one needs however an additional rule on what to do in the rare case  
that the president is included in the two but not in the three).

>
> (I still like my RBV method, and would still be willing to code it  
> open-source if the Czech greens are interested. But I understand if  
> they want something more proven.)

I didn't form yet any strong opinions on the RBV method. Is  
monotonicity the target that makes you like it more than STV?

Juho



>
> Jameson Quinn
>

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