Swing (Australian politics)

The term swing is used in Australia in a different sense from that employed in Britain, where the term originated (see Swing (politics)). For the Australian House of Representatives (and for the lower houses of the parliaments of all the 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 "two-party-preferred vote" ). The two-party swing is therefore the swing that will be required for that seat to change hands at the next election.

Here is an example of an election count for a House of Representatives seat, from the 2004 federal election.

First count

ADELAIDE, SA 95,060 enrolled, 88,996 (93.6%) voted =

Hon Trish Worth * Lib 38,530 45.3 +00.8 Richard Pascoe AD 1,355 01.6 -09.3 Kate Ellis ALP 35,666 41.9 +05.5 Amanda Barlow 978 01.1 Jake Bugden Grn 6,794 08.0 +02.0 Peter Robins FFP 1,753 02.1 -------------------------------------------------------------------- 3,920 (04.4%) informal 85,076 --------------------------------------------------------------------

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% (45.3 minus 41.9). (Note the very high turnout, due to Australia's compulsory voting law.)

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

2nd count: Barlow's 978 votes distributed -------------------------------------------------------------------- Worth * 172 (17.6) 38,702 45.5 Pascoe 139 (14.2) 1,494 01.8 Ellis 206 (21.1) 35,872 42.2 Bugden 365 (37.3) 7,159 08.4 Robins 96 (09.8) 1,849 02.2 -------------------------------------------------------------------- > 978 85,076 --------------------------------------------------------------------

3rd count: Pascoe's 1,494 votes distributed -------------------------------------------------------------------- Worth * 343 (23.0) 39,045 45.9 Ellis 494 (33.1) 36,366 42.8 Bugden 560 (37.5) 7,719 09.1 Robins 97 (06.5) 1,946 02.3 -------------------------------------------------------------------- > 1,494 85,076 --------------------------------------------------------------------

4th count: Robins's 1,946 votes distributed -------------------------------------------------------------------- Worth * 1,098 (56.4) 40,143 47.2 Ellis 377 (19.4) 36,743 43.2 Bugden 471 (24.2) 8,190 09.6 -------------------------------------------------------------------- > 1,946 85,076 --------------------------------------------------------------------

5th count: Bugden's 8,190 votes distributed -------------------------------------------------------------------- Worth * 1,262 (15.4) 41,405 48.7 ELLIS 6,928 (84.6) 43,671 51.3 -------------------------------------------------------------------- > 1,946 85,076 01.3 01.9 to ALP -------------------------------------------------------------------- Thus, Ellis defeated Worth, mainly because the great majority of Australian Greens voters gave their preferences to Labor. Ellis's two-party majority was 1.3%, and she gained a two-party swing of 1.9% as compared with the previous election. Assuming there is no change of boundaries, the Liberals will require a swing of 1.3% to regain the seat at the 2007 election.

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%. Thus the pendulum predicted that Labor will need a uniform two-party swing of 4.9% to win the 2007 election. Labor in fact gained a swing of 5.6%, 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