I compared the polls with the election night results here, but I thought it'd be good to revisit those now the final results are in. Although the movements after special votes are larger than they have been at previous elections, the trends are in line with what we've seen before.
As has happened at every election I can think of, National lost a seat after special votes and the Greens gained one. Some thought that it wouldn't happen this time because of the vote patterns on election night. National had only just lost their 62nd seat on election night, and the Greens had only just gained their 13th seat, so it required a big change in specials for National to drop again from 61 to 60 seats, and for the Greens to increase from 13 to 14 seats. As it happened, we got that big change, with National dropping more than 1% once specials were included. What that says is that the Greens and Labour both did much better on specials than they did on advance votes or on votes cast on the day - which means that the Labour & Green vote was relatively strong amongst people who registered late (likely to be younger and perhaps poorer) or who voted outside their electorates (including overseas).
In the last blog I included UMR's last pre-election poll (conducted September 15th to 18th), and I thought I'd have a look at how it compares with the final numbers.
- National: Actual 47.0%, UMR 47.4% (+0.4%)
- Labour: Actual 25.1%, UMR 26.3% (+1.2%)
- Greens: Actual 10.7%, UMR 11.9% (+1.2%)
- NZ First: Actual 8.7%, UMR 6.8% (-1.9%)
- Conservative: Actual 4.0%, UMR 3.9% (-0.1%)
- Maori: Actual 1.3%, UMR 1.7% (+0.4%)
- Internet Mana: Actual 1.4%, UMR 1.0% (-0.4%)
- ACT: Actual 0.7%, UMR 0.8% (+0.1%)
- United Future: Actual 0.2%, UMR 0.1% (-0.1%)
So we were about right (given margins of error) on National and the minor parties, too high on Labour and the Greens and too low on New Zealand First.
As I've mentioned before, polls are a snapshot of what's happening at that point in time, and can't take into account any shifts in the vote after they're completed. If a dramatic event occurred on the last day of the campaign, then that might well render the polls 'inaccurate' in terms of the final result through no fault of the polling company. I think it's symptomatic that the least 'accurate' of the public polls in 2014 was almost entirely completed before the 'Moment of Truth' - if the Moment of Truth helped National as several polls and other data suggests, then that poll won't have captured that. Similarly, our poll voters suggests that voters may have shifted in the last couple of days from Labour and the Greens to New Zealand First (and I think the former is more likely than the latter).
I pointed out in the previous blog that all the public polls and ours were within the margin of error of the election-night result for both National and Labour, and that finding has been strengthened by the final results. You may recall I compared previous elections with the final polls in an earlier blog, and came up with the conclusion that, HISTORICALLY SPEAKING, National tended to lose around 2% between the final polls and election day, while Labour stayed about the same, the Greens lost 1.5%, and New Zealand First gained around 1.1%. In 2014, taking the five public polls and our poll, we see that on average the polls had:
- National 0.5% too low
- Labour 0.4% too high
- Green 1.9% too high
- NZ First 1.2% too low.
So three of the four conclusions based on previous elections were also true in 2014, with the big issue being the fact that the polls actually had National about right as opposed to too low (I don't think that the sample sizes involved make it reasonable to conclude that the polls understated National's vote). I think the fact that four of the six polls had the bulk of their fieldwork conducted prior to the Moment of Truth (including one that was totally finished) may have contributed to National's vote bucking their historical trend.
Some final observations:
- National received more votes than they did in 2011, but actually received a slightly lower percentage of the total vote (due to more votes being cast).
- National + Conservative + ACT + United Future totals 51.9%, up from 51.6% in 2011.
- Labour + Green + Internet Mana (Mana in 2011) totals 37.3%, down from 39.6% in 2011.
- The centre (NZ First plus Maori) comes to 10.0%, up from 8.0% in 2011.