User:Timeshift9/drafts/Federal LH Pendulum
From Wikipedia, the free encyclopedia
The following pendulum[1] is known as the Mackerras Pendulum, invented by psephologist Malcolm Mackerras. The pendulum works by lining up all of the seats held in Parliament 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 oppostion or government parties, the number of seats that change hands can be predicted. The pendulum has been adjusted to include the many redistributions that have occured.[2] Labor will therefore need to gain 16 additional seats to obtain government, which translates in to a required swing of 4.8 percent. Swing is never uniform, but in practice variations of swing among the states usually tend to cancel each other out. Seats are arranged in safeness categories according to the Australia Electoral Commission’s classification of safeness. ‘Safe’ seats require a swing of over 10 per cent to change, ‘fairly safe’ seats require a swing of between 6 and 10 per cent, while ‘marginal’ seats require a swing of less than 6 per cent.[3]
