Saturday, September 7, 2013

Saturday morning update

This morning's polls:

  • Morgan 45.5 to 54.5 in the Coalition's favour
  • Newspoll 46 to 54 in the Coalition's favour
  • Nielsen 46 to 54 in the Coalition's favour

Which gives an aggregation:

At this point in the blog, it is my normal practice to remind people that I anchor the above Bayesian aggregation with the assumption that the net bias across all of the polling houses sums to zero. You will need to come to your own view about where the actual level of collective systemic bias lies for all the pollsters. At the 2010 Election (with a different set of pollsters), the population voting intention was about one percentage point more in the Coalition's favour compared with the pollster average (see here). In light of the 2010 experience, it is arguably plausible to subtract (say) half a percentage point or more from the above aggregation to adjust for the collective systemic bias across all of the polling houses. [As an aside, you will note that Simon Jackman, who seeks to anchor his Bayesian models with respect to the outcome of past elections regularly produces an aggregated poll that tracks well below the vast majority of individual poll results]. 

If we limit our analysis to Newspoll and Nielsen.

The latest Newspoll

The latest Nielsen

My prediction? Yesterday I thought it might be in the high 50s for the number of seats won by Labor. Today, with this latest suite of polls, I suspect the low 50s for Labor is more likely. But the high 40s cannot be ruled out.


  1. Looks like you're going to be quite close to the mark. 88 is the ABC's prediction and it looks about right.

  2. Thanks for you analysis. It was very informative, and as it turns out accurate.