Post-election pendulum for the 1980 Australian federal election

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The Mackerras pendulum as a way of predicting the outcome of an election contested between two major parties in a Westminster style lower house legislature such as the Australian House of Representatives, which is composed of single-member electorates and which uses a preferential voting system such as a Condorcet method or instant-runoff voting.

The pendulum works by lining up all of the seats held in Parliament for the government, the opposition and the crossbenches according to the percentage point margin they are held by on a two party preferred basis. This is also known as the swing required for the seat to change hands. Given a uniform swing to the opposition or government parties, the number of seats that change hands can be predicted.

Government seats (74) [1]
Marginal
Wilmot Tas Max Burr LIB0.1
Kingston SA Grant Chapman LIB0.2
Barton NSW Jim Bradfield LIB0.4
Riverina NSW Noel Hicks NAT0.5
Phillip NSW Jack Birney LIB0.6
Herbert Qld Gordon Dean LIB0.9
Perth WA Ross McLean LIB1.0
Lowe NSW William McMahon LIB1.1
Leichhardt Qld David Thomson NAT1.1
Bowman Qld David Jull LIB1.2
Northern Territory NT Grant Tambling CLP1.2
Bendigo Vic John Bourchier LIB1.3
Calare NSW Sandy Mackenzie NAT1.5
Fadden Qld Don Cameron LIB1.5
Canning WA Mel Bungey LIB1.8
Casey Vic Peter Falconer LIB1.9
Stirling WA Ian Viner LIB2.0
Chisholm Vic Graham Harris LIB2.2
Dawson Qld Ray Braithwaite NAT2.2
Deakin Vic Alan Jarman LIB2.3
Denison Tas Michael Hodgman LIB2.4
Franklin Tas Bruce Goodluck LIB2.7
Eden-Monaro NSW Murray Sainsbury LIB2.8
Moore WA John Hyde LIB2.8
Macarthur NSW Michael Baume LIB3.2
Petrie Qld John Hodges LIB3.4
McPherson Qld Eric Robinson LIB3.6
Diamond Valley Vic Neil Brown LIB3.7
Sturt SA Ian Wilson LIB4.0
Bass Tas Kevin Newman LIB4.3
Wide Bay Qld Clarrie Millar NAT4.4
Flinders Vic Phillip Lynch LIB4.6
Moreton Qld James Killen LIB4.6
Tangney WA Peter Shack LIB4.6
Cook NSW Don Dobie LIB5.1
Braddon Tas Ray Groom LIB5.1
Opposition seats (51)
Marginal
Kalgoorlie WA Graeme Campbell ALP0.6
Ballarat Vic John Mildren ALP0.7
Lilley Qld Elaine Darling ALP0.8
McMillan Vic Barry Cunningham ALP1.4
Isaacs Vic David Charles ALP1.8
Brisbane Qld Manfred Cross ALP1.8
La Trobe Vic Peter Milton ALP2.3
Macquarie NSW Ross Free ALP2.8
Henty Vic Joan Child ALP2.8
Grey SA Laurie Wallis ALP3.4
Hawker SA Ralph Jacobi ALP3.8
Hotham Vic Lewis Kent ALP4.0
Capricornia Qld Doug Everingham ALP4.3
Canberra ACT Ros Kelly ALP5.7
Fairly safe
St George NSW Bill Morrison ALP6.1
Hindmarsh SA John Scott ALP6.2
Holt Vic Michael Duffy ALP6.9
Swan WA Kim Beazley ALP7.6
Robertson NSW Barry Cohen ALP8.1
Adelaide SA Chris Hurford ALP8.5
Banks NSW John Mountford ALP8.8
Burke Vic Andrew Theophanous ALP8.8
Corio Vic Gordon Scholes ALP9.8
Safe
Parramatta NSW John Brown ALP10.2
Batman Vic Brian Howe ALP10.7
Maribyrnong Vic Moss Cass ALP10.7
Prospect NSW Dick Klugman ALP11.2
Hughes NSW Les Johnson ALP12.1
Melbourne Ports Vic Clyde Holding ALP12.3
Bonython SA Neal Blewitt ALP12.4
Fraser ACT Ken Fry ALP12.5
Griffith Qld Ben Humphreys ALP12.5
Fremantle WA John Dawkins ALP13.1
Grayndler NSW Leo McLeay ALP13.5

References

  1. Carr, Adam. "1980 House of Representatives Results". Psephos. Retrieved 2 July 2025.