David L Wetzell wrote:
This is based on what I've culled from empirical findings reported in
"Choosing an Electoral System".
<http://anewkindofparty.blogspot.com/2011/04/choosing-electoral-system-part-i.html>
1. While all forms of PR fall short of proportionality in
representation, the best predictor of proportionality is the number of
contested seats.
Only if there are enough parties to provide competition within all the
seats. If you consider a district that has 20% leftist voters (for
instance), if there's only one left party, then 20% of the seats (up to
rounding) will tend to be held by the leftist party. Not very contested;
and even if you get multiple leftist parties, these will not affect the
extent to which the right-wing seats (say) are contested.
Rounding may also amplify the apparent contested nature of the seats.
Say that a district has only two viable parties, and they're even -
49%-51% of support for each party. Then if you have single-member
districts, in times of 55% support for the first party, most of the
seats will go to the first party, and in times of 55% support for the
second party, most of the seats will go to the second party. Thus all
seats appear to be contested. Yet, with PR, each would get about half of
the seats, and some marginal seats would shift back and forth. That
would seem less competitive, but nothing about the popular support for
each party has changed: only how the seats are allocated has been.
Yet, PR with fewer seats induces more turnout than PR with a greater
numbers of seats. So the election rule that gives us proportionality
tends to make it so there are fewer competitive seats and less
uncertainty about election outcomes and consequently lower voter
participation.
The Hix-Johnston-MacLean document states that these effects are weak. To
quote:
"Turnout is usually higher at elections in countries with PR than in
countries without, It also tends to be even higher in PR systems with
smaller multi-member constituencies, and also tends to be higher where
citizens can express preferential votes between individual politicians
from the same political party rather than simply choosing between
pre-ordered party lists. In general, the more choice electors are
offered, the greater the likelihood that they will turn out and exercise
it. However these effects are not particularly strong, there is some
evidence that highly complex electoral systems suppress turnout, and
turnout levels may partly reflect influences other than the electoral
system, for instance in some countries voting is compulsory."
So I don't think you can necessarily draw that conclusion. The apparent
competitiveness between seats may be lesser (because of what I mentioned
above in that single-member districts are much more win-all/lose-all),
but that doesn't mean the real change in voter opinion from term to term
is any greater in SMD countries.
2. Proportionality in representation does not entail proportionality in
power and the latter is desired more than the former. As such, it seems
that minority dissenters will need to use extra-political methods (not
unlike #OWS) to move the center, regardless of whether PR or another
mixed system is used.
Proportionality in representation is correlated with proportionality in
power. The correlation isn't perfect, as Banzhaf and Shapley-Shubik's
measures make apparent, but to leap on that and conclude that
proportionality isn't proportional... that's unwarranted.
If anything, when proportional representation disagrees with
proportionality in power, the power favors the minority parties. Minor
party kingmakers can make themselves costly if they know there won't be
any coalition without them. Hence the presence of thresholds in most PR
systems: these keep too minor parties from becoming potential kingmakers.
Over here, the threshold of 4% keeps most "swing parties" (as one may
call them) out of power. Yet the threshold is soft - even parties below
4% of the total vote can get representatives, they just don't get
MMP-esque compensation on the national level. (Our PR system is a bit
unusual in this respect: parties get additional seats if their
per-region seats reflect their national share of the vote too badly.)
Perhaps you'd want a hard threshold for a less homogenous country, but
my point is that the problem can be managed.
3. If both PR and single-seat elections are in use and the latter favors
bigger parties then does PR need to be perfectly proportional or could
it be biased somewhat in favor of smaller parties? Might not the
opposing biases tend to cancel each other out?
That's somewhat the idea of MMP. In MMP you have a local election rule
and a PR rule. Usually the local election rule is Plurality and the PR
rule is party list, but you could use any combination. Schulze has
suggested using Schulze STV for a "deluxe" form of MMP - see
http://home.versanet.de/~chris1-schulze/schulze4.pdf for more about that.
So, yes, if you use both single-seat and PR in the same country without
linking the two in some manner, the bigger parties will tend to
acquire a disproportionate share of the seats when seats elected by both
methods are considered as one group. To fix this, you can add feedback
between the types (MMP), or just accept the disproportionality (parallel
voting).
These seem to imply that we need not strive for proportionality in
representation as the gold standard for electoral reform. If the two
major parties, with a somewhat disproportionate amount of
representation, are more dynamic then they'd tend to represent well the
majority of the population and heed minorities that frame their issues
respectfully.
Do note, though, that the same Lijphart as you referenced on your page,
said:
"If partisan conflict is multidimensional, a two-party system must be
regarded as an electoral straitjacket that can hardly be regarded as
democratically superior to a multiparty system reflecting all the major
issue dimensions." ("Democracies: Patterns of Majoritarian and Consensus
Government in Twenty-One Countries", 1984, page 114.)
----
Election-Methods mailing list - see http://electorama.com/em for list info
