Uneven Swing to Liberals in Tasmanian State Election Polling

Advance summary:

1. Figures from three 2012 polls of Tasmanian state voting intention, show that swings between different electorates since the 2010 election are clearly not uniform.

2. Especially, Labor is polling very much better than the state swing suggests in Franklin, but generally worse in the northern seats and Lyons.

3. For a Liberal vote of around 50, the uneven swing pattern makes little difference to the seat total, with the party projected to win 13 seats (the barest possible majority).

4. For a Liberal vote well above 50, as in the November 2012 EMRS poll, the uneven swing pattern means that the party does not necessarily win more than 13 seats.

5. However the uneven swing pattern also makes it possible (but not at all likely at this stage) for the party to win as many as 17 seats.


This article and its predecessor have now shown three reasons why uniform swing should not be assumed in any attempt to project the 2014 state election:

1. Historical evidence shows that at least two parties achieve (or suffer!) greater swings when/where their vote is higher and smaller swings where it is lower.

2. When a uniform swing model is applied to a large statewide swing, it produces some silly results.

3. Electorate breakdowns available for 2012 show in some cases, and suggest in others, that at present, both regional and candidate factors are creating non-uniform swings.

Factor 3, especially, is so strong that even models based on historical evidence alone are not likely to be sufficient. Effective modelling of the 2014 election will require careful use of electorate breakdowns from multiple polls (hopefully) issued closer to the date.

An important common factor in all these simulations is that it is very difficult to turn realistic numbers based on recent polling into a scenario in which the Liberal Party doesn’t win outright. As amusing as a parliament with exactly twelve Liberals and Kim Booth in it might be, the Liberals’ polling would have to come down a fair way before we had to take the prospect seriously.

Read more:

Earlier: Tasmanian State Election Patterns since 1989,

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