[EM] Raph: Sainte-Lague. Transfers in party-list PR.

[Raph Frank]

On Mon, Jul 16, 2012 at 2:27 PM, Michael Ossipoff
<email9648742 at gmail.com> wrote:
>
> On Sat, Jul 14, 2012 at 4:53 PM, Raph Frank <raphfrk at gmail.com> wrote:
> > I was thinking that "excess" above their fair share could be distributed.
> > If a party gets 25 seats but 25.2 seats worth of votes, the 0.2 could be
> > transferred.
>
> And the parties needn't publish whole rankings. Each party need only
> publish one other party to which it wants to transfer to if it
> transfers.

I think full rankings would be better.  If excess is being
transferred, then even large parties will transfer some of their vote.

If the rule is that any party which gets less than 2 seats is
eliminated and Sainte-Lague is used to distribute after the transfers
and eliminations, then only small parties need to list an alternative,
and then just 1 medium/large party is enough.  Parties which are sure
to get at least 2 seats wouldn't need to bother at all.

> But,again, just as with the transfers between parties, it seems to me
> that each candidate need only designate one other candidate to whom
> s/he wants to transfer, if s/he transfers.
> ..instead of publishing whole rankings.

Well, the idea is that it would be a national level PR-STV election,
but with a compromise to keep the ballot counting manageable.

> It seems to me that partes needn't have any official role.

Right.

> Well, I
> suppose a party could threaten to expel a candidate who transferred to
> someone they don't like, but party membership wouldn't be important or
> necessary in such a system.

That is what I am thinking.  I could easily see rules that your top 3
need to be party members (or even you must rank all party candidates
before any other candidates)

However, it does shift the power balance towards the candidates, so
there would be limits to what the party leadership could demand.

Candidates would also be under pressure to rank "local" candidates
higher on the list.

> There are many quite workable solutions. Parties (or other
> organizations) could agree among their members, that people with names
> beginning with certain letters would vote for certain candidates. Or
> that voters in certain geographical regions would vote for certain
> candidates. Or, as you suggested, a party or organisation could
> directly advise each voter which candidate to vote for, in the form of
> direct communications with voters, or via a published list that pairs
> voters with candidates.

The issue I have with this is that it means that voters are less free
to make intra-party choices, but that is inherent in the system.

This happens somewhat with "vote management" under PR-STV.  A
candidate who is popular in his own right is discouraged from seeking
first choices from party supporters.  This means that he gets elected
on "personal" vote and doesn't waste party supporters.

> But the voter could also be allowed to vote for several candidates of
> a party, and the candidates could be seated in order of their numbers
> of approvals.

There are lots of possibilities.  Approval isn't very proportional.

I think Asset voting might be interesting.

> Isn't that how it already is, in those countries that let voters vote
> for a _set_ of candidates on a party list (or even several party
> lists) if they want to?

I am not sure, I thought open list was mostly vote for 1.  I think the
Netherlands has a system where it is party list, but if you get more
than 25% of a quota, you skip the list (I guess they have a tie break
rule if to many get more than 25%).

> There's been inexplicably little innovation in single-winner methods.
> A few impressively progressive countries have been using a different
> single-winner method (IRV, also called Preferential Voting or the
> Alternative Vote). They deserve credit for progressiveness, and iRV
> would even be ok, if people would avoid over-compromise,and would be
> very particular what they regard as acceptable.

It seems from Australia that IRV leads to 2 party domination.
However, I am not sure if there are some subtle underlying effects of
IRV, maybe 3rd parties have more influence, even if they don't win.

I was thinking that an interesting tweak for IRV would be to modify
the rule for eliminations.

It assumes equal ranks are allowed.  Each candidate would have 2
totals.  For ballots where there are 2 or more candidates at the top
rank, there would be different rule for the candidates election total
and elimination total.

For election, the vote would be split equally between top ranked
candidates and for elimination it would operate at full strength for
all candidates.

Most of the properties of IRV are maintained no matter what the
elimination rule you use (as long as you don't eliminate a candidate
who has a majority of the votes).

So, in each round, you would check if any candidate has a majority in
his election total, where votes are shared.  If so, that candidate
wins.

If not, you eliminate the candidate with the lowest elimination total.

This gives approval like effects, where supporters can "support"
multiple candidates against elimination.

In the PR-STV context, it means that intra-party elections are
determined by approval voting, rather than IRV.