Monday, February 18, 2013

One of these things is not like the others

Recall that Sesame Street song ...

Well something like that is happening with the opinion polling at the moment. One of these pollsters is not like the others.

Once again I am left pondering Essential's steadfastness; when the other houses have moved away from Labor by a comparable 4 or 5 percentage points. It will be interesting to see if this divergence is just a point in time thing (either the other three move back to where they were or Essential moves), or whether it turns out to be a longer-term discontinuity. 

The weekly aggregation is unchanged on last week (46.1 to 53.9). But I am less comfortable with the notion that the zero-sum across polling houses is where the actual national voting intention lies. I suspect it is 0.2 or 0.3 percentage points to the left of the current average. I am working on strategies to better quantify when the sum-to-zero constraint may differ materially from the national voting intention (as it did at the last election).

Explanatory notes on the Bayesian aggregation can be found on the Technicals page.