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

[Juho]

Some more comments on how the male/female requirements could be handled.

In the description of Markus Schulze (see below) there were two steps  
where the male/female proportionality was handled. That approach works  
if there are separate requirements for the set of three first  
(vice)presidents and the rest of the council members. My understanding  
is that in the Czech Green Party there are no such requirements on the  
presidents. In that situation it may be better to push the forced male/ 
female election to the end of the list. It may be better to allocate  
the resulting problems in the last seats and elect the first seats in  
a more optimal way. It could also be a problem if we for example know  
what the three largest groupings that are likely to get the three  
first seats are. In that situation the idea of forcing the third  
grouping to always be the one that will be forced (if needed) not to  
elect their best candidate doesn't sound fair. Towards the end of the  
list the level of randomness is higher and the groupings that get  
those last seats may be happier to get them and never mind if the  
representative is male or female.

This style of ensuring that appropriate number of male/female  
candidates will be elected is not optimal. It is for example possible  
that the fourth elected representative has an alternative of other sex  
that is about as popular as the elected president. In that case it  
could make sense to elect that alternative and in that way avoid the  
need to do some more violent changes later on the list.

This approach of pushing the forced decisions towards the end of the  
list is however a working although somewhat ad hoc solution. More  
accurate solutions may be much more complex, e.g. ones that compare  
all possible sets of representatives and then pick the one that  
distorts proportionality with respect to voter preferences and sex  
related proportionality as little as possible. What would be a better  
but still simple approach?


If one pushes the forced elections towards the end of the list the  
method could look as follows.

--Use a Condorcet based proportional ranking method.

--The top-ranked candidate becomes the president.

--The second-ranked candidate becomes the first vice president.  
(optional step)

--The third-ranked candidate becomes the second vice president.  
(optional step)

--Also the following n candidates will become members of the council.

--If at some point in the process all the remaining representatives  
must be male or female to make sure that the number of male/female  
candidates will meet the requirements, then restrict the consideration  
to male or female candidates only.


This approach is thus not an optimal way to handle the sex  
requirements but maybe good enough and at least a simple one.

(I note that Raph Frank proposed also an approach where the election  
of the last representative would be free of these sex related  
requirements. That is one way of relieving the proportionality related  
problems since at least the last choice that often distorts  
proportionality the most can be done quite freely. I'm not sure how  
big the improvement would be. There may be also other more  
sophisticated approaches as noted above.)

Juho




On May 4, 2010, at 5:03 PM, Juho wrote:

> This is a good approach in the category of simple (only one method  
> used) proportional ranking based methods.
>
> Use of proportional ranking reduces the proportionality of the  
> council and the set of n presidents a bit but not much.
>
> The election of the president can be seen to happen before the  
> election of the council.
>
> Same ballots are used for all elections. => Good for simplicity.  
> Some small restrictions if the election criteria for P are different  
> from the criteria of VPs and those of the council members.
>
> The last vice president positions are probably not needed. Their  
> order will probably become public but should maybe not be emphasized.
>
> Markus Schulze of course recommends a Schulze method based approach  
> but also any other good Condorcet method could be used as the basis.  
> The Schulze family of methods has the benefit that it is quite well  
> documented and the basic single winner Schulze method is also  
> already used in some organizations. Probably Markus Schulze will  
> also provide assistance in the promotion of the methods and related  
> software. All these variants are however very similar so the  
> argumentation and software is pretty similar in all cases.
>
> I support this approach as one proposal in the category of simple  
> proportional ranking based methods. No need to limit to the Schulze  
> method based approach only but to allow also other base methods to  
> be used (e.g. Ranked Pairs, minmax(margins)). Also other categories  
> or maybe variants of this one should/could be discussed and proposed  
> as alternative approaches.
>
> Juho
>
>
>
> On May 4, 2010, at 3:42 PM, Markus Schulze wrote:
>
>> Dear Peter Zbornik,
>>
>> this is my proposal:
>>
>> --Use the Schulze proportional ranking method.
>>
>> --The top-ranked candidate becomes the president.
>>
>> --The second-ranked candidate becomes the vice president.
>>
>> --If the first two candidates happen to be male, then,
>> when you calculate the third-ranked candidate, restrict
>> your considerations to female candidates.
>>
>> If the first two candidates happen to be female, then,
>> when you calculate the third-ranked candidate, restrict
>> your considerations to male candidates.
>>
>> The third-ranked candidate becomes the 2nd vice president.
>>
>> --The fourth-ranked candidate becomes the 3rd vice president.
>>
>> --The fifth-ranked candidate becomes the 4th vice president.
>>
>> --If 4 of the already elected candidates happen to be male,
>> then, when you calculate the sixth-ranked candidate, restrict
>> your considerations to female candidates.
>>
>> If 4 of the already elected candidates happen to be female,
>> then, when you calculate the sixth-ranked candidate, restrict
>> your considerations to male candidates.
>>
>> The sixth-ranked candidate becomes the 5th vice president.
>>
>> --The seventh-ranked candidate becomes the 6th vice president.
>>
>> Markus Schulze
>>
>>
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