[EM] British Colombia considering change to STV

[Juho Laatu]

--- On Tue, 5/5/09, Raph Frank <raphfrk at gmail.com> wrote:

> > Btw, one way that this approach might
> > somewhat simplify things is that the
> > votes could be shorter than in STV.
> > (There might be such shortening needs
> > also to keep the votes unidentifiable
> > (to avoid vote buying and coercion).
> > Maybe limiting the number of entries
> > in the ballot could be used in some
> > cases for this reason.)
> 
> Right, but it depends on how many choices there are.
> 
> With 100 candidates and PR-STV, you can have potentially
> 100! different votes.
> 
> With 100 candidates, 30 groups and 10 parties and 4 ranks
> allowed, you
> are still looking at around 400 million different
> combination. (even
> if this is still much lower).
> 
> Ofc, if most people just pick a candidate and use his list,
> then there
> would be much fewer possibilities.

Yes. One may need to go to quite low
numbers if one wants to be sure that
there will be no problems. On the other
hand in most problem cases the vote
must contain also the intended voting
pattern, which means that the part that
identifies the vote will be smaller. If
the vote would e.g. allow only three
codes, then one could try to mark a vote
to candidate C111 by ranking also two
candidates that certainly will not win.
The vote could be e.g. C999>C888>C111.
Pairs of candidates like C999 and C888
might be rare enough to allow some vote
buyer to mark numerous ballots.

The default inheritance rules will help
since also short votes will carry lots
of inheritance information in them.

Number of candidates and size of
districts whose results will be reported
are also important (and existence of
"hopeless" candidates too). I remember
one example from open list elections. A
voter was happy that she voted for her
friend as she said to her since the
results of different voting stations
were published (to her surprise) and
there was only one vote to the candidate
in question from the local voting
station. (=> Also voter privacy needs to
be protected.)

- - -

Some more observations.

- -

Widespread use of the default
inheritance paths means that parties
may nominate more candidates than
before (in STV) and still keep most
of the voting power within the party.
It may also be beneficial to nominate
numerous candidates (like in open
lists today).

- -

The named parties and groups are in
a special position when compared to
groupings that might exist as a result
of many people voting them. E.g. votes
C1>C2>C3>C4 and C2>C3>C1>C5 generate a
group C1+C2+C3 that gets at least two
votes. The tree structure sets some
limits on what kind of groupings may
exist. We may however relax the rules
a bit. One could name also "orthogonal"
groups that consist of candidates of
different branches, e.g. "candidates of
town X" or "all female candidates".
This would make it easier for the
voters (there may be many such voters)
to vote for these groups.

I noted earlier that the seat allocation
rules may also observe votes that will
be inherited by a certain group. This
may make the treatment of named and
non-named groupings somewhat different.

This kind of additional named groupings
will assist the voters. But on the other
hand they will also corrupt the basic
idea of the tree structure (to offer a
clean understandable structure of the
political world to the voters). If the
additional groups are listed only at
some special secondary place they might
not be too confusing.

Actually there could in principle be also
alternative complete hierarchies. If the
primary hierarchy is a typical political
party structure the alternative hierarchy
could be e.g. a geographical structure.
A vote to the candidates of town X could
be inherited by candidates of the
surrounding district. (A candidate could
have a code in more than one hierarchy.)

- -

One of my key points in this discussion
is to demonstrate that there is a space
and continuum of methods between open
lists / trees and STV.

The maximum number of codes per ballot
may vary for various reasons. Value 1
means actually just a basic tree method
(if there is only one hierarchy). Also
small values thus work quite well.
Larger values allow more personalized
votes (a la STV).

The space could cover also closed lists.
It would be a quite straight forward
extension to use one code to refer to
a list of candidate instead of only one.
01: C1
02: C2>C3>C4
A vote to 02 would have a mandatory
order of inheritance. Code 02 could
represent a party that wants to decide
itself which of its candidates will be
elected. (Voters might or might not
agree with this approach.)

This structure could also allow
candidate defined inheritance orders.
Code 02 above could be seen as a vote
to C2 with inheritance as planned by
C2. C2 could have also a different code
that would not include the inheritance
order (to allow voters to either vote
as recommended by C2 or to create their
own order of inheritance). These tricks
may again confuse the voters by giving
lots of new thoughts and patterns to the
voters (instead of relying on the basic
tree structure).

Candidates C3 and C4 might not have any
codes of their own.

- -

This is enough for now. Maybe I'll one
day get also to the alternative seat
allocation methods. :-)

Juho