The term swing is used in Australia in a different sense to 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) 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 their preferences. Swing in a British political context is a mathematical calculation which allows the results of two constituencies to be compared. ... Australian House of Representatives chamber Entrance to the House of Representatives The Australian House of Representatives is one of the two houses (chambers) of the Parliament of Australia. ... Emblems: ? (please edit) Motto: Ubertas et Fidelitas (Fertility and Faithfulness) Slogan or Nickname: The Apple Isle Other Australian states and territories Capital Hobart Government Governor Premier Const. ... A how-to-vote card from the Australian federal election of 2004, showing voters how to fill in the squares on the ballot paper if they wish to vote for the Liberal Party of Australia and allocate preferences according to the Partys recommendations. ...

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. The two-party swing is therefore the swing that will 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. Legislative elections were held in Australia on 9 October 2004. ...

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.) The Division of Adelaide is an Australian Electoral Division in South Australia. ... The Liberal Party of Australia is an Australian liberal conservative political party. ... The Australian Democrats (in regular parlance, just the Democrats), is an Australian social liberal party formed in 1977 from the earlier Australia Party by Don Chipp, who left the Liberal Party of Australia to do so. ... The Australian Labor Party or ALP is Australias oldest political party. ... The Australian Greens, commonly known as The Greens, is the national Greens party in Australia. ... The Family First Party is a political party in Australia. ... The Liberal Party of Australia is an Australian liberal conservative political party. ... Hon Trish Worth Patricia Mary Trish Worth (born 21 April 1946), Australian politician, was a Liberal member of the Australian House of Representatives from March 1993 to October 2004, representing the Division of Adelaide, South Australia. ... The Australian Labor Party or ALP is Australias oldest political party. ... Kate Ellis (in the blue and white) is regularly in camera shot behind speakers in the House of Representatives Kate Ellis (born 22 September 1977), Australian politician, was elected to the House of Representatives as member for the Division of Adelaide, South Australia for the Australian Labor Party at the... Compulsory voting is a practice that requires citizens to vote in elections or to attend a polling place and get their name crossed off the electoral roll. ...

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. The Australian Greens, commonly known as The Greens, is the national Greens party in Australia. ... The next Australian legislative election is expected to take place in 2007. ...

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 neverthless fail to win the seat, because "preference flows" go against them.

By taking the two-party majorities of all 150 federal electorates and arranging them in order, from the seat with the highest Liberal majority to the seat with the highest Labor majority, it is possible to calculate the two-party swing which will be necessary for Labor (currently in opposition) to gain the seats needed to defeat the incumbent Liberal government in 2007. To win the election Labor needs to win 16 seats, and the 16th weakest government seat (McMillan) has a two-party majority of 4.9%. Thus Labor will need a uniform two-party swing of 4.9% to win the 2007 election. The Division of McMillan is an Australian Electoral Division in the state of Victoria. ...