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

[Markus Schulze]

Dear Peter Zbornik,

you wrote (9 May 2010):

> In your paper schulze3.pdf, there are some instances,
> where the Schulze proportional ranking fails to produce
> an unambiguous ordering (see for instance the result
> for data set A10). Why do there ambiguities occur and
> how would you recommend them to be resolved in a
> deterministic manner without resorting to random number
> generation etc?

In 5 instances (A10, A12, A23, A33, A67), the Schulze
proportional ranking is not unique. This is caused by
the small numbers of voters and the large numbers of
candidates.

For example, in instance A10 (83 voters, 19 candidates),
there are two possible Schulze proportional rankings:
NAPMQFGRSLIBDJKEHOC and NMPQAFGRSLIBDJKEHOC.

You wrote (9 May 2010):

> Does Schulze-STV allow for truncated ballots? I.e. when
> there are 5 candidates, does Schulze-STV allow me to
> only rank two of them on my ballot?

I recommend "proportional completion".
This is explained in section 5.3 of
http://m-schulze.webhop.net/schulze2.pdf
and in the file calcul01.pdf of
http://m-schulze.webhop.net/schulze3.zip

You wrote (9 May 2010):

> I am also curious to know, if you think it would be
> difficult for you to implement a program, which would
> handle the green council elections in an optimal
> proportional manner, i.e. methods, which would only
> impose the required ranking.

It would be simple to incorporate all the requested
specifications. Send me an input file with explanations.

Markus Schulze