On May 23, 2010, at 10:40 PM, Aaron Armitage wrote:
I've considered the question myself, although I've never described my
ideas publicly. Now's as good an opportunity as any.
I came at it from the opposite direction, so to speak; trying to graft
lists onto STV to make it scalable, rather than adding candidate
rankings
to a list system. The basic idea is to use the lists as a shorthand,
so
that voting for a list is the same as voting for all those
candidates in
an STV ballot. I think the political environment makes a difference
between the two approaches. In a parliamentary system you probably
want to
go party first, allowing the parties to know where they stand for the
negotiations in forming a government even before the individual
candidates
are elected. In America, the parties don't form a government in any
case
(we don't even have a government in the European sense, the
administration
and the majority in Congress being different things altogether), and
there
is so much time between elections and inaugurations that speed isn't
important, even though people like it. On the other hand, if the
counting
is done quickly enough it may not matter, and a delay of a few days
normally shouldn't matter much even to a parliamentary system.
The first way of adding lists to STV is simple: you list your
candidates,
and last you put a list, which fills out the rest of your preferences
according to the predefined order of the list. I suppose you could
include
more than one list, or a list then a candidate, but that would be
pointless because your vote would be used up.
A simple example: The Yellow list is A>B>C>D>E, and
the Brown list is F>G>H>I>J. If you vote B>I>Yellow, it counts as
B>I>A>C>D.
The second way is more sophisticated, and much more complex to
count. The
vote itself needn't be any more complex (you could always just vote
a list
and leave it at that), but it can be, and depending the layout of the
ballot it may look more visually confusing. It will really need to
be done
with a touch-screen, preferably using a drag-and-drop interface. A
paper
ballot should be printed out and kept as a check (or perhaps the paper
count should be all there is, the computer interface being simply the
means of generating the paper ballots).
Instead of using regular STV, the second way uses CPO-STV. Since
it's a
Condorcet method, it allows tie votes which amount to voting present
in
the choice between them. Or, in the case of CPO-STV, between two
outcomes
which differ only in electing one or another of tied candidates. The
lists
are unordered and instead of representing a completed ordering
filled in
at the end of the ranking, they are a tie between all list members.
The
party lists will probably be mutually exclusive, but there's no
reason not
to have other lists which overlap the party lists and each other. If a
candidate appears in two lists which are ranked on the same ballot, he
takes the higher of the two positions, but if he is ranked
individually,
as a candidate, he takes that rank regardless of how any of his lists
might be ranked.
So, going back to the previous example, say you vote
B>Vowels>Yellow>Brown>Purple>F>White. This becomes:
B > (A,E,I,O,U,Y) > (C,D) > (G,H,J) > (K,L,M,N) > F > (P,Q,R,S,T)
This is a good generic approach to how voters could express their
opinions.
In an open list system a vote to candidate A of Yellow party would
mean A>Yellow.
In a tree based system (that is also one approach to combining list
and candidate orderings) a vote to candidate A could mean
A>Subgroup1>Subgroup2>Yellow>Partygroup3.
Ability to vote for overlapping groups can be a real benefit to
voters. It is quite well possible that some vote for candidate X
because she belongs to some certain ideological group and some others
because she represents some geographic region.
One could also have tree based systems where the candidates may be
included in multiple branches. The counting process of course becomes
more complex then. One candidate could be both part of a candidate
group that represents the northern region and a candidate group that
oppose nuclear power. The voter could decide which "variant" of this
candidate gets her vote.
Trees do limit the ability to use user generated rankings /
inheritance order but votes are very simple, just votes to one
candidate. Trees could be used also as default orderings if the voter
doesn't express anything else.
Notice that separating out a candidate can be used to bury as well
as help
him. In the example above F is rated lower than anyone but the
detested
White Party.
This feature is a bit dangerous, for the same reason as negative votes
are. It is ok if voters know what they are doing but it could also
lead to problems. Voters could e.g. generally vote A>Party>B>C>D where
B, C and D are either the strongest competitors of A or just
candidates that are well known and therefore many people also dislike
them. As a result some very unknown or/and weak candidate(s) from the
"Party" list might win.
Registering seven ranks for only five seats may seem like overkill,
but
every outcome is compared to every other outcome, and you may not have
used up your vote by the time your grudging preference for F over
White
matters.
Already single-winner elections with multiple candidates could make
good use of multiple levels.
Most voters won't have such detailed preferences, of course, and
they can just vote Yellow (or Purple or...) or even bullet vote. If
that's
all they care about, that's fine. But if a voter has more
preferences to
express, the system should include that information and make use of
it.
That allows the ordering of the lists to be entirely voter-generated,
based on overlaps with other lists and individual rankings.
I just note that tree based default inheritance order is different
from party given preference order since there are no "safe" seats but
voters will decide which branches will get the seats. Trees provide
thus also fully user-generated results although they set some
limitations on what kind of orderings are possible. (Parties could try
to put their "favourites" in the tree next to some candidates that are
known to get lots of votes but voters will still decide if they will
give that branch votes, and which candidates on that branch will get
the seats.)
The second system also allows for a kind of MMP to be added. The
larger
district (or the whole country, or the state, as the case may be) is
split
into single-member districts. The single members are elected
according to
some suitable method -- Condorcet is best, both for the usual
reasons and
because all the tie votes represented by list rankings can be given
their
full weight, but if we just have to we can use IRV, Bucklin, or even
plurality. Once the local winners are found, the larger CPO-STV
election
proceeds considering only those outcomes which include the local
winners.
In MMP style systems one must be careful not to lose proportionality.
(In the Czech Green Party discussions there was some discussion on
this. The election of the president and the council have to be linked
somehow to maintain proportionality (since the president os also part
of the council).)
In summary I think there are many opportunities in this kind of
extensions of the basic proportional methods. The biggest challenges
are in complex calculation rules and complex ballots (or complex and
tedious filling of the ballots even if the ballots themselves are not
that complex).
Juho
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