polling trust in media
(Image: AAP/Lukas Coch)

The federal election result appears to be the tipping point in public confidence in political polls. Of the hundreds of recently published polls and exit polls, can anyone find one predicting a win for Scott Morrison? Can political polling now be trusted to accurately predict an election result?

The answer could be that we are now in an era of “fake polls”. And more disturbing, those fake polls are the basis for an industry of academics and journalists who rely upon them to provide analysis. If the polls are fake, the news and commentary can only be wrong.

There was a time we had confidence in polling results. Here are some of the issues which have taken political polling to an existential crisis.

Representative sampling

The magic of polling was introduced by Gallup in 1936. Polling would be accurate if it captured, in microcosm, a representative sample of the public. Butchers, bakers, candlestick makers were assessed in microcosm and their views extrapolated to the broader national public. For some decades this worked brilliantly.

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But things have changed very rapidly.

Think of a “representative baker” now. Is it the hipster in Newtown or Northcote baking artisanal sourdough, or the employee of a Coles bakery? And what is the baker thinking? What are his points of engagement with the world, the things that help shape his attitudes?

A few decades ago we could predict with significant accuracy the stimuli he would be exposed to. Today, is it Netflix bingeing, social media, free-to-air TV, or the infinite spectrum of the internet and immersion in algorithmic designed filter bubbles?

How do we sample his mindset today? How do we extrapolate this mindset? How many are there like him?

The collapse in response rates

If there is a problem in defining representative samples, there is a greater problem in simply getting people to participate in a poll.

Participation rates have collapsed. Once a public duty, there now appears more a type of person who will respond to a poll, and as importantly a type who will not. We have shifted from most people willing to participate in a poll to overwhelmingly most people not wanting to participate.

Not wanting to participle in something has meaning. What are the views of the type of person who does not participate in a poll? We simply don’t know.

Two-party preferred

The key paradigm of major public opinion polls is flawed. The polls measure a supposed swing between the major parties. This is represented in the two-party preferred result — 2PP. But the 2PP paradigm is a stark distortion of public voting behaviour.

If there is a swing in modern Australian politics, it is a swing against the major parties, rather than between them.

The collapse in major party identity is a key ingredient in the current inability of published polls to provide accuracy. For example, over the last 25 years both the ALP and Coalition have slowly reduced their primary votes. The ALP has lost over 25% of its primary vote in 25 years.

The very voters who have rejected the two-party option are now being squeezed and disfigured to fit the 2PP poll paradigm.

Traditional voters who have always voted the same way provide a great service to the current polls. They are the reason we do not have high volatility of results in political polling, and we do not get wild poll swings of 10% or 20% in error. The traditional voters anchor polls. For example, if 75% of voters don’t change their vote, any volatility is quarantined to the remaining 25%. So it is easy to see why even failing predictions are reasonably close to the final voting result A 2% error across the whole sample looks accurate, but when applied to the volatile area, represents an error rate of 8%.

This has masked the emergent errors in polling. But the voter anchor is rusting away; the slow erosion of party identity is adding to the inability to rely on predictive political opinion polls.

There was no “bang” or key moment to mark the point that political polling failed. It is the recent and accretive impact of many factors. There is really no one to blame, and it is not quarantined to Australia, but we must recognise there is a problem with our supposed ability to predict election outcomes. The magic has gone.

How much faith do you have in the polls? Send your comments to boss@crikey.com.au.