Juho Laatu wrote:
On 9.7.2011, at 14.23, Kristofer Munsterhjelm wrote:
Juho Laatu wrote:
After some recent discussions and thoughts around two-party
systems I thought it would be interesting to discuss two-party
systems also in a more positive spirit. The assumption is thus
that we want the system to be two-party oriented. We want to have
two strong parties, and one of them should rule. We want to allow
only well established parties with wide support to rule. The
first obvious approach is to ban all other parties than the two
leading parties. But maybe we don't want to be so brutal. Let's
not ban the possibly already existing, much liked and hopeful
third parties. It is also good to have some competition in the
system. Let's not allow the two leading parties think that they
don't have to care about the voters and they can do whatever they
want, and stay in power forever. What would be a good such
method? In addition to what was already said we surely want e.g.
to avoid the classical spoiler problems.
I can think of two simple PR-based methods.
In the first, you use ordinary divisor-based PR, but set the
divisors so that they have a great large-party bias (even worse
than D'Hondt).
It seems that this method would favour large parties so that they
would get lots of seats, and it would make sense to generally vote
for them. One problem with respect to the targets might be that small
parties may have problems to grow since votes to them have less
weight than votes to large parties. If left wing gets 50% of the
votes, and in the right wing there are two parties, 35% and 15%, then
left wing gets majority. The small party was a spoiler to the right
wing.
It's relatively simple to get around such troubles: just slap an Asset
patch on it. For that matter, you could have Asset with the requirement
that the negotiations don't end until one of the parties has greater
than a majority of the assets.
In the second, you also use ordinary divisor-based PR, but top up
the list of the largest party so that it always gets 50%+1 of the
seats if it would otherwise get below that.
It seems that also here we may have a spoiler problem. In situation
40: L1, 10: L2, 40: R1, 10: R2 any additional voters moving from a
40% group to the 10% group of the same wing would be spoilers.
Same response :-)
If you want to deal directly with the spoiler problem, you'd need a
method that has the property that it grants every party a score, and
that cloning groups of parties gives one of the group of parties (since
the method can't know which are clones) the same score as the original
party would have if there was no cloning.
But I think that any two-party system will discourage smaller
parties. If only the two major parties can rule, voters will
strategically think that "either I can use my vote to grant the
lesser evil more seats/power so it can defeat the greater evil, or
I can use my vote to vote for a small party that hasn't got a
chance beyond being the opposition anyway. I'll do the former".
That sort of thinking will create an invisible barrier to third
parties, because as long as the third parties aren't large enough
that they might win (become one of the top two) with a small amount
of additional votes, voters won't vote for them, and if they don't
vote for them, they'll never get close enough to the threshold.
There might be irrational fears, that may be based on how the old
methods have worked. The target is anyway to make such fears
irrational. The intention is that although my favourite small party
can not win this election, it is quite possible that it will win in
the next election, or one after that.
Even If the votes are now 50: A, 45: B>C>A, 5: C>B>A, next time they
could be 50: A, 35: B>C>A, 15: C>B>A, and next time 50: A, 24: B>C>A,
26: C>B>A. C should thus be able to grow without disturbing the
balance between A and {B, C}. (These votes should work in the method
that I proposed.)
That could work, if there was some way of measuring support so that
voters of minor parties could see that they're helping the minor party
get closer to major status. However, if the measure of support is the
number of seats, then either a vote gives a major party another seat (or
the ability to get past the threshold), or the vote gives a minor party
the ability to get past the threshold.
You could then say that if there's an effective seat barrier (the
threshold) so that minor parties don't *get* any more seats until
they're at major party status, then voting for the minor party first
won't harm your vote if that vote doesn't lead to the minor party
getting more seats, because then your vote can help your major party
instead; and the minor party can't get seats before it's at major party
status, so your vote isn't harming your major party until the point
where it would help the minor party more than it harms the major party.
This kind of logic is similar to that in Condorcet methods, (assuming
CW, etc), you don't really risk anything by putting Nader first, because
either Nader is elected, in which case that's what you wanted, or he's
not, which means your vote will help elect Gore instead of Bush.
That reasoning itself is sound enough, but I still think it would need
some sort of "contingent score", so that people who vote the minor party
first can see that the minor party is increasing in support, even if
that support doesn't give them seats. If the voters are under a time
constraint, then voters who would otherwise not bother to consider the
third parties might, once they see that one of them is getting close to
becoming a major party.
I can think of two ways to get around that, but both would bend the
definition of a two-party system.
Let's call the first an "explicit coalition system". The election
process itself is party list PR. After the election is done, a
group of parties with a total vote share greater than a majority
must form a coalition; they do so by an internal supermajority
vote, after which this group gets the government and the rest
becomes the opposition. After that is done, they rule until at
least one of the parties (or some fraction of the whole group),
plus the opposition (or supermajority thereof), agrees to dissolve
the current coalition. After that is done, there are new elections.
The current coalition rules until the next coalition can organize
itself.
Are you saying that actually many multi-party systems (that work
pretty much in the described way) are actually single-party
governments, and therefore the system is essentially a government vs.
opposition system, and that would make it effectively a two-party
system? It is true that governments typically have a unified policy,
and the opposition takes the opposite position. Technically this
approach meets the two targets that I set, but I was thinking of
somewhat more stable parties, not ones that would be redesigned after
every election based on the results that the numerous smaller parties
that participate in the election do get :-).
It's a more hardened version of a coalition. Note that there are no
minority governments in that system: the government has to be led by a
coalition. Furthermore, the coalition isn't very loose: it has to stay
together to remain in power, and the parties can't be released from the
coalition in contentious matters. All of these aspects make it less a
coalition in the PR sense and more a single party - a metaparty that
consists of the parties in the coalition.
From the actions of the current coalition in Norway, the coalition
being quite "hard" in that sense, I don't think this sort of system
would be preferable to pure PR, but it might be better than R-and-D
party-leadership type two-party systems. (Then again, I also think that
this is more or less an intellectual exercise: I wouldn't want a
two-party structure in the first place, and if you had an electorate
that did, you could just use an ordinary representative system since the
voters would vote to preserve the two-party system, like in Malta.)
(Note that I wrote the targets for a single-winner election (they
talk about electing one of the candidates) and we have now expanded
the discussion also to multi-winner elections. They are
interchangeable though, since many single seats van be summed up to
multiple seats, and multiple representatives can elect a single
winner, maybe a government coalition or a president.)
I think it's simpler to consider party list PR methods than STV-type
ones since party list can go directly to parties and give different
winners different power. Then, if it is required, one can go from the PR
methods to the STV-methods later, trying to find out how to embody the
same logic in a more complex system.
The second, I'd call "PR by credit". Again, votes are counted as in
party list. Each party also has an "account". After the election,
the number of votes for each party is added to the relevant party's
account. Then the parties allocate votes to gain seats in a
continuous bidding process. That is, call parties 1...n's current
bids, B_1...B_n. Then the tentative seats allocation is according
to some major-party biased divisor method that considers B_1...B_n
the number of votes each party got. The seats count is updated
continuously until the timeout, then each party's bid is withdrawn
from its account. While it is unfair in any given election, the
smaller parties can accumulate votes in their accounts and later
use this to take the throne of government, if for only a term.
However, I think this kind of hybrid monetary system would have
some adverse results. First, it would cause great oscillations. The
composition of the parliament could swing hard left, with lots of,
say, environmental bills, then swing hard right, with the new
government scrambling to undo those bills and to impose their own,
then swing hard left again, each sweep of the pendulum causing
chaos. Second, differences in turnout could add more noise: if
there's less turnout, there's less of an impact to each party's
account.
I think two-party countries typically oscillate between two extremes.
Or actually they are not extremes since both major parties tend to
move close to each others in the hope of making some of the voters of
the other party to move on their side. But oscillation of one-party
governments tends to be the rule. Although in multi-party systems
governments tend to be "compromise based combined governments" we
need not follow that rule in our two-party system.
True, but I don't think it's a good way of governing :-) Say you're
driving a car, and you turn the steering wheel to the left until the
left of your car is at the middle of the road. Then you turn your
steering wheel right until the right side of your car is at the edge of
the road. Then you turn left again... sure, the mean position of your
car will be in the middle of your lane, but I don't think your
passengers would be very happy if you drove that way.
The median voter theorem might moderate the amplitude of the direction
changes, but it is not absolute, since the Republican and Democratic
parties do indeed differ. Someone (I don't remember who, but it might
have been Warren) argued that the conflict between the median voter
theorem (that means the two parties have to be similar) and the parties'
desire to seek their own way meant that they essentially had to lie to
the voters: seem more centrist than they really were. If that's true,
that's not a desirable property, either.
This kind of oscillation and also credit based methods typically
offer proportionality in time (instead of "proportionality now" as
multi-party parliaments or governments). I'll propose one additional
method to explain what I mean and how this relates to the interest of
letting only the major parties rule.
Let's say that the votes are approval votes. All parties have credit
accounts that contain unused ballots from the previous elections. The
votes of this election will be added to the credit accounts. The
winner is the party with most credit ballots. We will delete as many
ballots from that party as there are voters (total number of voters)
(some fine-tuning may be needed because the number of voters may
change between elections). Note that we deleted actual ballots, i.e.
also those other parties that were approved in some of these ballots
lost some ballots from their account. Maybe we will subtract votes
proportionally so that ballots with different approval patterns will
be reduced in same proportion (some fine-tuning maybe here too, maybe
all ballots to this party only will be eliminated).
Obviously (as you've discovered), you can't just store the Approval
counts for each party in the party's account. That would lead to a
significant teaming problem where a party makes ten clones and then
whenever the main party wins, the clones can win the next ten terms. (It
gets worse with an Asset patch.) So you have to remove actual ballots
when you remove votes, as you've mentioned. However, that could lead to
rather strange outcomes.
Say that there were some voters in term t who voted both left and right.
Then in term t+1, the right party decides to use some of its credit.
Would that then also decrease the left party's credit (because of the
votes from term t)? If not, then teaming is possible, otherwise, it's
possible to add noise to the credit by having party voters also vote for
another party, and then just removing those ballots later on.
Now we have a system that puts one party at a time in power. It is
fully proportional in time in the sense that all parties will get
their time in office one day. But if we want to stop small parties
winning the election unless they grow into large parties we need some
additional rules. One could for example allow only parties that have
reached some predetermined number of votes in this election to win
(or...). We could also eliminate votes that are older than five
elections. There are also other tricks (fine-tuning and more coarse
tuning possible again).
That's easy enough. Simply add a negative "interest rate". At the
beginning of each election, a certain percentage of the total is removed
from everybody's credit. Small parties have no chance to accumulate more
quickly than the interest removes credit from them. To see this clearly,
consider a -100% interest rate. Then that is the same as having no
credit at all, which turns the system very majoritarian. On the other
end, a 0% rate would let every party, however small, win after enough terms.
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