Horizon Poll

Sarah Harvey in the SST reports:

THE COUNTRY’S next prime minister could be decided by New Zealand First leader Winston Peters.

A new poll has cast Peters as kingmaker. The 65-year-old left parliament after 30 years as an MP when he lost in Tauranga to Simon Bridges and New Zealand First failed to pass the 5% party list MP threshold in the last election.

The Horizon poll of almost 2000 intending voters shows the often-controversial MP could have the power to decide whether National’s John Key or Labour’s Phil Goff leads the country after the 2011 elections.

In 2008 New Zealand First captured just over 4% of the vote, but the Horizon poll, conducted from November 16-22, shows the party is back in the game with 6% support.

In the same poll National recorded 34.7% support, Labour 28.3%, the Greens 7.9%, Act 2.6%, the Maori Party 1.2%, Jim Anderton’s Progressives 1.2%, United Future 0.2% and other parties 1.6%.

That left undecided at 8.1% and those who preferred not to say at 8.2%.

A key thing to note here in Horizon use an online panel to do their polling. Online panels are growing in usage, but the reliability of them varies greatly.

I am sure Horizon, like almost all polling companies, tries its utmost to be as accurate as possible. Any criticism of their results, is not a suggestion that they are not applying professional standards. It is a reflection that online panels pose extra challenges in terms of how the panel is recruited, how large it is, what topics they are given etc etc.

In trying to assess reliability, one often looks at a couple of things – how do polls stack up against known results, and against other polling companies.

In terms of known results, their final exit poll for the Auckland Council did predict correctly Len Brown would win, but the margin was well off.

Mr Brown has 53.7% support among those who have cast votes. John Banks has 23.8%, Colin Craig 10.4%, others 6.4% and 4.6% will not say who they have voted for.

Taking away the 4.6% who would not say, that is 56.3% for Brown, 24.9% for Banks and 10.0% for Craig. Projected margin was 31%.

The final result was Brown 49.2%, Banks 35.6% and Craig 8.8%  a margin of 14%. The support for Banks especially was significantly under-reported. Now to be fair to Horizon, this may have been due to a last minute surge in Banks voting.

In Sep they released a poll saying National had 30%, Labour 22%, and 27% were not voting, unsure ore refused to say. Removing the 27% to get a % of decided voters (to allow comparisons to other polls), and you have the poll saying National has only 41% of decided voters and Labour 305 of decided voters.

That 41% for National is a figure well away from any other poll. In August and September there were seven other public polls released – the average had National at 51%.

Then we have the latest poll. It has National 34.7%, Labour 28.3%, Green 7.9%, NZ First 6.0%. This translates to a share of decided voters being National 41.5%, Labour 33.8%, Green 9.4%, NZ First 7.2%, ACT 3.1%, Progressives 1.4%.

By contrast the latest Roy Morgan has National 51%, Lab 33%, Green 7%, NZ First 3%, ACT 1%.

There is no sure fire way of saying this poll is definitely accurate or inaccurate. I wish there was.

But I find it very hard to give reliance to the Horizon results. They have twice shown National at 41% – around 10% below where everyone else has them.

They have NZ First at 7% of decided voters – I have not seen anything to indicate that, or any events to explain that.

I even have problems with the result showing Progressives at 1.4% considering they are not standing again.

I do give credit to Horizon for a couple of things. They show the results for both all voters and decided voters. The level of undecided voters is important. Many companies only give out the decided vote share.

They also probe people who are undecided to see which way they are leaning. This is done by most public policy companies, but not 100%.

But I do not think NZ First is at 7% of decided voters. I do think that you can not rule out NZ First making 5% in 2011 if for example Michael Laws is a candidate for them, as Michael would appeal to a considerable following in talkback land. But at this stage it doesn’t look like Laws is standing for them – but never say never.