As most of you probably know, the AEC has issued their Federal Election Determination on the forthcoming redistribution. The result is that NSW will lose a seat before the next Federal election and Qld will gain a seat.
There will be enormous argy bargy over the redistribution – so it might be worth a look at how the population has changed in each seat in NSW and Qld, both over the longer term (2001 to 2006) and the shorter term (2006 to 2007). We can also run a scatter plot of this population change against the ALP two party preferred result from the 2007 Election (to give a little context of who might win or lose out of the redistribution).
First up, the longer term population change:
And the short term population change:
Finally, it would be worth taking a look at the actual enrolment size of the seats in NSW and Qld. Again we’ll scatter it against the ALP TPP at the 2007 Election. The enrolment data is the latest published AEC data on the size of the voting population for each seat and comes from December 2008.(Small Update – new data just came out for January – unless I was having a moment earlier this morning and missed it. It doesnt change anything much – a few hundred here and there at most)
UPDATE:
Just playing around a bit, I found this interesting for QLD seats – the blue line is a simple regression line.
The bigger the growth in voter enrolment in a QLD seat, the larger – on average – was the swing to the ALP.
UPDATE 2:
Also worth looking at is the enrolment change against the proportion of the electorate receiving Family Tax Benefit Part A
You can really see how most of the enrolment growth seats are filled with the ALP target demographic of FTB A. The more you look, the bigger the reasons become for FTB A becoming the new ALP political prism.
3 Comments
Hi, Possum
Interesting points about the FTB A correlation, but there might be an added twist in the way the AEC does its redistributions.
Because it wants to smooth the process out, it allows for smaller average electoral enrolments in states where it expects population growth; could this mean that your FTB A recipients get a little bit more weight on their votes by virtue of having children?
I started thinking about this at the last election, when I noticed how many very large electorates (100K+) were turning up in SA and Victoria (as well as in the ACT, though obviously there are different issues involved with its representation).
If you take the current average electorate size and the growth in enrolments since January 2004 for Qld, SA and Vic, this is what you get:
Average electorate size Increase in total enrolments (%)
Qld 91234 9.6
SA 98205 4.4
Vic 94131 7.1
The effects are complicated by the fact that fast-growing outer-urban areas tend to be relatively poorly represented because of the time-lag in redistributions within states. But just looking down the individual electorates, I’ve got a feeling that your Qld recipients of FTB-A will be getting more weight for quite a while to come. Their counterparts in Victoria ain’t doing so well, even before the bushfires.
The risk in all this is that the AEC makes unwarranted projections based on yesterday’s news.
Possum,
Further to Jenny Lee at 1 I have been trying to understand this part of the Electoral Act for the last few months with little success.
The numbers of seats per state are calculated by dividing the population of the Australia by the number of MPs. Exceptions being made for Tasmania and the territories. The seats are then distributed according to the number of electors in that state. There must be a reason for using population figures in one calculation and electors in the other but I do not know it.
Therefore, as per the AEC determination of Feb this year there was an average population of 147 367 in each electorate in QLD versus 145 151 in NSW. This was enough to trigger an increase in representation in QLD at the expense of NSW.
The AEC elector figures show that at about the same time the average number of electors in each state was 91 234 in QLD and 92 245 in NSW. The redistribution would seem to widen this gap in electors numbers per electorate rather than reduce it.
Initial I thought that states with high migration or high birth rates would have the lower number of electors per electorate but the opposite seems to be the case.
Does anyone know what factors are in play?
Geoff, you’ve got the calculation around the wrong way. The average population per electorate calculated by the AEC is 144,496. This is used as a divisor, which gives NSW 48.2 electorates and Queensland 29.6. These numbers are rounded to 48 and 30, which produces the slight variation between states.
Population is used to allocate seats to states because that is what Section 24 of the Constitution says must be done. Once that allocation is done, the AEC uses the electoral act to draw boundaries which specifies enrolment be used.
So the differences you get are to do with the fractions of seats produced by the division calculations.