Canning ByElection - Libs to win 54-46 TPP

Been having a look at some of the crazy predictions around the Canning By Election. People saying its 51-49 Liberal. I think that is far too generous for Labor. There will be a swing against the Libs, based on the ReachTel Polls, but nothing like that.


Firstly, lets look at the results of the 2013 election in the seat of Canning
Primary Votes:


Liberal: 51.07% (65.72% of Labor/Liberal Primary Vote)
Labor: 26.64% (34.38 of Labor/Liberal Primary Vote)


Of the remaining 22.29% of the Other Primary Vote, 10.74% of preference votes went to the Libs (or 48.18% of the Labor/Liberal Preference flow) while 11.55% went to Labor (or 51.82% of the Labor/Liberal Prefence flow)


So we had the final TPP Numbers of
Liberal: 61.81%
Labor: 38.19%


Now based on the ReachTel Polling performed for Marriage Equality on 31st of August, we have the Primary Votes as follows
Liberal: 44.6% (58.53% of the Labor/Liberal Primary Polling)
Labor: 31.6% (41.47% of the Labor/Liberal Primary Polling)


This seems to indicate a Primary Vote Swing to Labor in the order of (65.72-58.53) = 7.19%


If we assume that that Primary Swing is also reflected in the Preference votes of the "Other Primary Vote" that totals 23.8%..it means we will have (51.82+7.19)= 59.01% of the Other Vote going to Labor, and 40.99% going to the liberals.


So for our Two Party Prediction we have


Liberals = 44.6+(0.4099*23.8) = 44.6+9.77= 54.37
Labor = 31.6+(0.5901*23.8) = 31.6+14.03 = 45.63


A good result for Labor (a swing of 7.2%), but certainly not a loss of seat.