May poll aggregate update

Another month has passed, so it is time to update the poll aggregate. Let's start with a list of the recent poll results, sourced from the Wikipedia page on the next federal election.

	MidDate	Firm	L/NP	ALP	GRN	ONP	OTH	TPP L/NP	TPP ALP
1	2018-04-30	ReachTEL	36.0	35.0	11.0	6.0	12.0	48.0	52.0
2	2018-04-20	Essential	37.0	36.0	11.0	8.0	8.0	47.0	53.0
3	2018-04-22	Newspoll	38.0	37.0	9.0	7.0	9.0	49.0	51.0
4	2018-04-06	Essential	38.0	37.0	10.0	7.0	8.0	47.0	53.0
5	2018-04-06	Newspoll	38.0	37.0	10.0	7.0	8.0	48.0	52.0
6	2018-04-04	Ipsos	36.0	34.0	12.0	NaN	18.0	48.0	52.0

Tossing these results into the two-party preferred aggregation reveals.

This can be compared with my simplified aggregation models using Henderson moving averages (HMA) and Locally Weighted Scatter-plot Smoothing (LOWESS). Both of these models can do strange things at the end points. Given the data, I suspect they are a touch over-enthusiastic for the Coalition come the end of April 2018.

Collectively we can see that the Coalition's fortunes continued their rise through April. Nonetheless, if an election was held now, the most likely outcome would be a sizable Labor victory.

Moving to the primary voting intention results.

Collectively, the implied two-party preferred (TPP) results for the Coalition follow. Unlike the TPP charts above, calculating the TPP results directly from the primary vote sees a stagnating TPP. I suspect the issue here is partly affected by Newspoll's change in methodology for attributing preference flows for One Nation. While I can understand Newspoll's decision to increase the One Nation to Coalition preference flows (based on preference flows at the recent Qld and WA state elections), the changed methodology is inconsistent with my models. I will need to think about this some more.

Speaking of One Nation, there has been a slow decline in its vote share over recent months.