[EM] proportional constraints - help needed

Jameson Quinn jameson.quinn at gmail.com
Wed Feb 6 11:56:35 PST 2013


2013/2/6 Peter Zbornik <pzbornik at gmail.com>

> Jameson,
>
> I am not sure if we understand each other here.
> I am looking for an election system, where the quoted-in seat gives
> (or moves toward) a proportional distribution of the quoted-in gender.
> If we fix the seats which will be quoted-in at no. 2 and 5, the
> quoted-in gender will in some cases not be proportionally distributed,
> for instance when the same group of voters get both quoted-in
> candidates at places 2 and 5.
>

OK. I was responding to your initial statement of the problem, without this
additional proportionally-quoting-in constraint.

The issue with this constraint is that it is only meaningful if the
electorate is meaningfully separable into parties. If, on the other hand,
the electorate is in a 2D issue space, it's hard to see exactly what this
constraint even means. Thus I suspect no non-partisan system can be made to
fit this constraint. I could easily see how to meet this constraint with a
party list system (preferably open, because closed list systems are bad),
and possibly I could work it out with a pseudo-list system like PAL, but
with STV it looks to me like an impossible task.


> I think the problem is not restricted to STV, so other election
> methods might be used and extended to resolve it, like Schulze STV.
> The problem is not to quote in the underrepresented gender at place 2,
> the problem is to proportionally quote-in the second seat at seat 3, 4
> or 5, in order to get a proportional distribution of the quoted-in
> gender.
>
> A special case is when two women are elected to seats 1 and 2, and
> three men are elected to seats 3, 4 and 5.
> Here, the constraints are also breached, but with diferent gender for
> seats 1 and 2 and for seats 3, 4 and 5.
>
> Again, it would be unfair, if, with three coalitions, the same
> coalition would get both quoted-in candidates.
> Now, the solution for this problem would be to look for
> proportionality of quoted-in candidates.
> I am not sure, that we are looking for proportionality within each
> gender, but rather proportionality of quoted-in candidates.
>
> PZ
>
>
> 2013/2/6 Jameson Quinn <jameson.quinn at gmail.com>:
> > STV is not my personal favorite PR rule (my favorites are Bucklin
> > Transferrable Vote or PAL Representation, and Schulze PR is also better
> than
> > STV). However, if you're starting from STV, the way to do the quota is
> > clear. When the quota makes one gender ineligible for a seat, simply
> ignore
> > that gender of candidates on all ballots. That's not just about
> > eliminations; it also means the count of the top preferences on each
> > (reweighted) ballot means the top eligible preferences.
> >
> > So say there are 7 piles of votes (as an unrealistic illustrative
> example):
> >
> > 18: W0 W1 M1 W2
> > 17: W0 W1 M2 W2
> > 16: W0 W1 M3 W2
> > 15: W0 W1 M4 W2
> > 14: W0 W1 M5 W2
> > 13: W0 W1 M6 W2 M5
> > 7: W3
> >
> > For the first seat, the unanimous choice W0 wins, and all votes are
> rescaled
> > to 5/6 strength. For the second choice, you ignore the preferences for
> > ineligible candidates W1, W2, and W3, and so M6 is eliminated and M5 wins
> > with the transferred votes. Etc.
> >
> > Jameson
> >
> > 2013/2/5 Peter Zbornik <pzbornik at gmail.com>
> >>
> >> Dear all,
> >>
> >> We recently managed, after some effort to elect some people in our
> >> party using STV (five of seven board members of the Czech Green Party
> >> and more recently some people to lead the Prague organisation etc.).
> >> We used standard fractional STV, with strict quotas, valid empty
> >> ballots, Hagenbach-Bischoff quota, no Meek.
> >> It was the first bigger usage of STV in the Czech republic.
> >> As a footnote, I would like to add, that one big advantage of
> >> proportional election methods, is that it elects "the best people",
> >> i.e. meaning the people, who have the biggest support in the
> >> organisation.
> >>
> >> Now we would like to go on using STV for primary elections to party
> >> lists in our party.
> >> I have a good idea on how to do it using proportional ranking, but am
> >> not entirely confident in how to implement the gender quotas.
> >> So here I would like to ask you, the experts, for help.
> >> I have only found some old papers in election-methods, but they are
> >> not of any great help to resolve the following problem, unfortunately.
> >>
> >> The problem (after a slight simplification) is as follows:
> >> We want to elect five seats with any proportional ranking method (like
> >> Schulze proportional ranking, or Otten's top-down or similar), using
> >> the Hagenbach-Bischoff quota
> >> (http://en.wikipedia.org/wiki/Hagenbach-Bischoff_quota) under the
> >> following constraints:
> >> Constraint 1: One of the first two seats has to go to a man and the
> >> other seat has to go to a woman.
> >> Constraint 2: One of seat three, four and five has to go to a man and
> >> one of those seats has to go to a woman.
> >> Say the "default" proportional ranking method elects women to all five
> >> seats, and thus that we need to modify it in a good way in order to
> >> satisfy the constraints.
> >>
> >> Now the question is: How should the quoted seats be distributed in
> >> order to insure
> >> i] that the seats are quoted-in fairly proportionally between the
> >> voters (i.e. the same voters do not get both quoted-in seats) and at
> >> the same time
> >> ii] that the proportional ranking method remains fairly proportional?
> >>
> >> ---
> >>
> >> Here is how I have been thinking about the problem myself.
> >> I am not sure, however, that my line of thinking is the best or the
> >> only one, so please read with a healthy amount of scepticism.
> >> The problem can be re-formulated as follows.
> >> Which method would make sure,
> >> 1) that a large number of voters do not get both of the quoted seats?
> >> 2) that the quoted seat is by default seat two and five, unless there
> >> are compelling reasons to quote-in seat three or four (or, less
> >> probably, seat one)?
> >>
> >> There is a trade-off between questions 1) and 2) above, i.e.:
> >> a) if seat two and five are quoted, then a large number of the voters
> >> might get both the quoted seats - which would lead the quotas to be
> >> non-proportionally distributed, making some voters dissatisfied.
> >> b) assume we always quote in seat two (this could, but need not be
> >> necessary). If we, by using some appropriate proportionality measure
> >> (has to be defined), quote-in the candidate at seat three, four or
> >> five, then a fraction of one vote might decide, that the quoted-in
> >> seat should be seat number three instead of seat five, or the rule
> >> could "prefer" quoting in at place three, instead of place five, as
> >> place three would need to have higher support, than place five. Such a
> >> quota rule would ignore the fact, that place three is more important
> >> than place five, i.e. that the disturbance in the proportionality of
> >> the proportional ranking would be higher, if the candidate would be
> >> quoted in at seat three than seat five.
> >>
> >> I.e. we search for
> >> a) a quota proportionality measure and
> >> b) a proportional ranking measure and
> >> c) a rule, which "optimises" both the "quota proportionality" and the
> >> "proportional ranking proportionality".
> >>
> >> I am sure the above was not entirely easy to digest.
> >> I am happy to take your questions and will do my best to clarify.
> >> Any references to relevant papers would be more than welcome.
> >>
> >> Best regards
> >> Peter Zborník
> >> ----
> >> Election-Methods mailing list - see http://electorama.com/em for list
> info
> >
> >
>
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