Impact of Redistributions in South Australia and Victoria

I’ve spent a bit of time calculating the impact of the redistributions in districts throughout South Australia and Victoria (which took place after the 2010 election) on each district. The table below shows the impact of the redistributions for Victoria state for Labor, the Liberal group, the Greens and Family First (click on the table for an easier read):

Victoria Redistribution Table

The biggest changes took place in the McEwen district, which saw a significant shift to Labor. The Greens will lose about 1.2 percentage points in the Melbourne district, the only seat in Parliment they currently hold. Unless there is a major reduction in Green support however, they should hold this seat in the upcoming election. The Casey district tightened up in favor of Labor but the Liberals are likely to hold this seat.

The next table shows the effect of the redistribution in South Australia state:

South Australia Redistribution

The redistribution’s effect was much less in South Australia than in Victoria with only the Hindmarsh district appearing to experience any significant potential impact.

The next stage in my work is to input the effect of these changes into my model and then calculate how the race in districts with no incumbent should change compared with 2010. With these figures in hand, I will then calibrate the 2010 polls with my model and with that calibration in hand, I will be able to make my first forecast for the upcoming election.

The 2010 Australian Election – South Australia

South Australia is big (about the size of Texas and Nevada combined), but with only about 1.65 million population (a bit greater than Idaho). The state is also extremely arid except for areas near the coast in the state’s southeastern corner. This is where the state’s largest city, Adelaide, with a metropolitan population of about 1.26 million people or about three quarters of the state’s residents. Adelaide is the westernmost of Australia’s ring of cities that dot the country’s east and southeast coasts. West and north of Adelaide are some of the earth’s greatest deserts. Adelaide has a Mediterranean climate and its average temperatures are about 2 degrees Celsius higher than Melbourne. It’s annual average rainfall of about 550 mm (21.5 inches) is approximately the same as that of San Francisco.[1]

 Map 1

Position of South Australia in Australia

 667px-South_Australia_in_Australia.svg

Map 2

South Australia Major Cities

south-australia

The Liberal and Labor groups were separated by less than 2 percentage points in the 2007 election in the state and the margin separating them slipped to about 0.5 percentage points in the 2010 election. A 5 percentage point Green surge between 2007 and 2010 in the state (and its attendant preference vote distribution in favor of the Labor group) allowed Labor to maintain unchanged from 2007 its 6-5 seat advantage in South Australia. The midstream Liberal group parties ran a strong 5.3% in the state:

 2010 House of Representatives Election

South Australia

First Preference Votes

Group or Party

Candidates

Votes

% Share

Seats

Liberal Group

11

394,003

40.2%

5

Labor Group

11

399,279

40.7%

6

Greens

11

117,364

12.0%

0

Midstream Liberal Group

15

51,471

5.3%

0

Upstream Group

20

17,832

1.8%

0

Downstream Independent

0

0

0%

0

Midstream Independent

0

0

0%

0

Totals

 

 

100%

11

Source: Australian Election Commission

 Preference Vote Distribution 2010 Election

South Australia

From/To Liberal Group Labor Group Net
Greens

33,335

105,324

-71,989

Midstream Liberal Group

27,379

12,326

15,053

Source: Australian Election Commission

2010 Vote Totals After Midstream Preferential Distribution

South Australia 

Group

Votes

% Share

Liberal Group

454,717

46.40%

Labor Group

516,929

52.75%

Source: Australian Election Commission


[1] All of information in the paragraph is from Wikipedia.