Swing (Australian politics)

The term swing is used in Australia in a different sense from the one employed in the UK. For the Australian House of Representatives and the lower houses of the parliaments of all the Australian states and territories except Tasmania and the ACT), Australia employs preferential voting in single-member constituencies. Under this system, voters number all the candidates on their ballot paper in the order of their preference. Minor candidates are eliminated and their votes are distributed among the remaining candidates according to these preferences.

Thus, in every Australian election using this system, there will be only two candidates remaining at the end of the count. Thus, it is possible to calculate a two-party majority for every seat, also described as the two-party preferred vote (2PP). The two-party swing is therefore the swing that will be required for that seat to change hands at the next election. Whilst seats are normally referred to on 2PP terms, when one of the remaining two candidates after preference distribution are not from a major party, it is referred to as a two-candidate preferred vote (2CP), with a different 2PP produced. Whilst each seat that preferences down to two major party candidates has the same 2PP as 2CP, in seats not contested by a major party, only a 2CP vote can be produced.

Examples

Federal, Adelaide 2004

Australian federal election, 2004: Division of Adelaide, South Australia
Party		Candidate	Votes	%	±%
	Liberal	Trish Worth	38,530	45.29	+0.82
	Labor	Kate Ellis	35,666	41.92	+5.50
	Greens	Jake Bugden	6,794	7.99	+2.02
	Family First	Peter G Robins	1,753	2.06	+2.06
	Democrats	Richard Pascoe	1,355	1.59	−9.30
	Independent	Amanda Barlow	978	0.15	+1.15
Total formal votes			85,076	95.60	+0.66
Informal votes			3,920	4.40	−0.66
Turnout			88,996	93.62	−1.09

It can be seen that the sitting Liberal member, Trish Worth, had a lead over her Australian Labor Party opponent, Kate Ellis. In a British election, Worth would have retained the seat, and her majority would be said to be 3.4 percentage points (45.3 minus 41.9). (Note the very high turnout, due to Australia's compulsory voting laws.)

In this election, however, the votes of all the minor candidates were distributed as follows:

2nd count: Barlow's 978 votes distributed
Party		Candidate	Added votes	%	Votes	%
	Liberal	Trish Worth	172	17.6	38,702	45.5
	Democrats	Richard Pascoe	139	14.2	1,494	1.8
	Labor	Kate Ellis	206	21.1	35,872	42.2
	Greens	Jake Bugden	365	37.3	7,159	8.4
	Family First	Peter G Robins	96	9.8	1,849	2.2
Total			978		85,076

3rd count: Pascoe's 1,494 votes distributed
Party		Candidate	Added votes	%	Votes	%
	Liberal	Trish Worth	343	23.0	39,045	45.9
	Labor	Kate Ellis	494	33.1	36,366	42.8
	Greens	Jake Bugden	560	37.5	7,719	9.1
	Family First	Peter G Robins	97	6.5	1,946	2.3
Total			1,494		85,076

4th count: Robins's 1,946 votes distributed
Party		Candidate	Added votes	%	Votes	%
	Liberal	Trish Worth	1,098	56.4	40,143	47.2
	Labor	Kate Ellis	377	19.4	36,743	43.2
	Greens	Jake Bugden	471	24.2	8,190	9.6
Total			1,946		85,076

5th count: Bugden's 8,190 votes distributed
Party		Candidate	Added votes	%	Votes	%
	Liberal	Trish Worth	1,262	15.4	41,405	48.7
	Labor	Kate Ellis	6,928	84.6	43.671	51.3
Total			8,190		85,076	1.3

Thus, Ellis defeated Worth, mainly because the great majority of Australian Greens voters gave their preferences to Labor. Ellis's two-party preferred vote was 51.3 percent, a two-party majority of 1.3 points, and a two-party swing of 1.9 percent compared with the previous election.

Frome, South Australia 2009

The 2009 Frome by-election was closely contested, with the result being uncertain for over a week. Initial reports suggested a slight swing to the Liberal candidate Terry Boylan on the two-party preferred count against Labor, but with Independent candidate Geoff Brock not far behind Labor. By 21 January 2009, both the ABC's Antony Green and the State Electoral Office were indicating a two percent swing against the Liberals toward Labor, but not enough to lose the seat. Liberal leader Martin Hamilton-Smith claimed victory on behalf of the party.

Frome state by-election, 17 January 2009
Party		Candidate	Votes	%	±%
	Liberal	Terry Boylan	7,576	39.24	–8.86
	Labor	John Rohde	5,041	26.11	–14.93
	Independent	Geoff Brock	4,557	23.60	+23.60
	Nationals SA	Neville Wilson	1,267	6.56	+6.56
	SA Greens	Joy O'Brien	734	3.80	+0.06
	One Nation	Peter Fitzpatrick	134	0.69	+0.69
Total formal votes			19,309	97.12	+0.21
Informal votes			573	2.88	–0.21
Turnout			19,882	89.79	–4.44
Two-party-preferred result
	Liberal	Terry Boylan	9,976	51.67	–1.74
	Labor	John Rohde	9,333	48.33	+1.74
Two-candidate preferred result
	Independent	Geoff Brock	9,987	51.72	+51.72
	Liberal	Terry Boylan	9,322	48.28	–5.13
	Independent gain from Liberal		Swing	N/A

The result hinged on the performance of Brock against Labor in the competition for second place. Brock polled best in the Port Pirie area, and received enough eliminated candidate preferences to end up ahead of the Labor candidate by 30 votes.

Distribution of Preferences - 4th count
Party		Candidate	Votes	%	±%
	Liberal	Terry Boylan	8,215	42.54
	Independent	Geoff Brock	5,562	28.81
	Labor	John Rohde	5,532	28.65

Brock received 80 percent of fifth count preferences to achieve a two-candidate preferred vote of 51.72 percent (a majority of 665 votes) against the Liberal candidate, despite a slight improvement in the Liberal primary vote since the previous count. This was announced by the Electoral Commissioner, Kay Mousley, at 8:30 pm local time on 24 January 2009, but without a formal declaration. The commissioner rejected a request for a recount by Boylan, with a formal request being lodged by the Liberal Party, which was also rejected, after which the Liberals ruled out a possibility of taking the result to the Court of Disputed Returns. A formal declaration of the by-election outcome was made by the State Electoral Office on 29 January. The by-election saw a rare two-party swing to an incumbent government, and was the first time an opposition had lost a seat at a by-election in South Australia. The result in Frome at the 2010 state election saw Brock increase his primary vote by 14.1 percent to a total of 37.7 percent and his two-candidate vote by 6.5 percent to a total of 58.2 percent. Despite a statewide swing against Labor at the election, Labor again increased its two-party vote in Frome by 1.8 percent to a total of 50.1 percent (coincidentally, 30 votes).

Summary

Thus it can be seen that the concept of "swing" in Australian elections is not simply a function of the difference between the votes of the two leading candidates, as it is in Britain. To know the two-party majority of any seat, and therefore the two-party swing necessary for it to change hands, it is necessary to know the preferences of all the voters, regardless of who they give their first preference votes to. It is not uncommon in Australia for candidates who have comfortable leads on the first count to nevertheless fail to win the seat, because "preference flows" go against them.

The Mackerras Pendulum takes the two-party majorities of all electorates and arranging them in order, from the seat with the highest government majority to the seat with the highest opposition majority. For example, ahead of the 2007 election, Labor needed to win a minimum of 16 additional seats to form a government, and the 16th weakest government seat (McMillan) had a two-party majority of 4.9 points. Thus the pendulum predicted that Labor will need a uniform two-party swing of 4.9 points to win the 2007 election. Labor in fact gained a swing of 5.6 points, which the pendulum had predicted would result in 21 additional Labor seats under a uniform swing. In fact, Labor gained 23 seats, and not all seats that changed hands were the ones with the slimmest Coalition majorities, because swings in each district are unique and not uniform.

See also

• Mackerras Pendulum