Everyone today has an opinion or three on whether the latest Newspoll is the 47th end of the Rudd honeymoon or a polling outlier. The most likely answer is probably a bit of both.
Newspoll certainly moved — 7 points worth of the Labor Party primary vote shifting straight across to the Coalition column is a serious piece of political activity, equating to nearly 1 million voters changing their minds over the last fortnight on which major party they’d vote for.
Yet over the last two weeks, both Essential Report and Morgan were in the field and neither pollster picked up any similar change in voter sentiment. If we compare the primary vote and two party preferred poll results of these three pollsters over the last couple of months, we can see that the latest Newspoll result has seriously broken from the pack.
The slight problem here is that Morgan and Essential both use two week’s worth of polling data for their voting estimates compared to Newspolls’ single week — so Morgan and Essential Report are generally smoother than Newspoll over any given period of time, with most small weekly fluctuations getting washed out of the system.
Still, from the polling data we have, if there was a significantly large change in the true underlying value of public opinion over the last two weeks — like a massive 7 points worth — we would have expected to see it turn up in Essential (whose latest poll covers the period of the 20th October through to the 1st November), and we would have expected to see it partially turn up in the latest Morgan (that was in the field from October 17th to the 25th).
Yet neither pollster really budged an inch.
However that doesn’t mean that public opinion hasn’t moved — just that it’s highly unlikely to have moved quite as much as today’s Newspoll suggests. That’s not unusual in political polling — polls can and do often overshoot simply as a function of the probabilistic statistics that make them up . The Newspoll at the time of the APEC meeting in the lead up to the 2007 election is a perfect example, although that nearly lead to a Prime Minister resigning on the basis of sampling error — which probably would have been a first in global political history.
Ultimately we will have to wait for further polls, with perhaps Nielsen being the next out of the stables — but a population doesn’t change 7 points of political support overnight and not have it picked up by two out of three pollsters. A two party preferred of 54 or 55 perhaps, but a two party preferred of 52 after sitting above 58 for three Newspolls straight? An acute outbreak of sobriety at Flemington today is far more likely.