The claim

Greens Leader Richard Di Natale says the growth of his party and independents continues with each election because Australians are "sick and tired of the old parties".

"We don't have people who go into a polling booth and say: 'I'm voting for the Greens or for Nick Xenophon because my grandfather did it and my mother did it and that's who I am," he said on the ABC's Q&A on May 30, 2016.

"That identity politics is breaking down, you just need to look at the vote amongst young people. If there was a vote amongst people who are under 30 in Australia, there'd possibly be a Greens prime minister."

Would a vote among Australians aged under 30 possibly deliver a Greens prime minister? ABC Fact Check investigates.

The verdict

Senator Di Natale's claim is far-fetched.

Experts contacted by Fact Check referred to opinion polls of young voters, acknowledging this data can lack reliability, mainly because of small sample sizes.

Additionally, pollsters do not commonly use the under 30 age category to break down data, instead opting for categories including 18 to 24 and 18 to 34.

Polling data from Newspoll, Ipsos, Roy Morgan, and Essential Media show the Greens are not the most popular party among young voters, although some polls put the Greens at a close second to Labor.

In relation to the 2013 federal election, figures from the most recent Australian Election Study survey put the Greens' popularity among people aged from 18 to 29 more than 25 percentage points behind the major parties around that time.

Assessing the claim

There would never be a parliament elected only by people aged under 30.

Fact Check therefore takes the view Senator Di Natale is asserting that the Greens are the most popular party among voters aged under 30.

Fact Check has used opinion polls to assess whether the Greens are likely to receive the highest proportion of the primary vote in this age group.

Are the Greens popular enough to provide the prime minister based on a vote by under 30 year olds, either by winning the majority of seats or negotiating the prime ministership in the event of a hung parliament?

How useful are the polls?

Nick Economou, a senior lecturer in politics at Monash University, told Fact Check: "Opinion polls are a very useful guide for us in trying to get a feel for how the electorate's going. The problem starts to arise when we fragment the data to try and get insights into more specific things."

He said accuracy is a particular problem for polling data broken down by age as "the rule of thumb is the more you break down the opinion polls data, the smaller the sample size becomes and the greater the margin for error."

He said people may tell pollsters they would vote for the Greens but change their mind on election day, adding that "the Greens' performances are always overstated in the opinion polls — in the last federal election the polls were saying the Greens would get 12 per cent and they only got eight".

Ian McAllister, a professor of political science at the Australian National University, said several factors influence the reliability of polls.

"There's known biases in all of these surveys. If it's [via] telephone, are they using mobile as well as landline? Because younger people are more likely to be mobile than landline only," he said.



"Normally the surveys are weighted to reflect all these biases but it's something obviously to bear in mind."

He said the larger the sample size, the more reliable the poll, adding that respondents may change their mind by election day.

William Bowe, researcher at the University of Western Australia's political science department and editor of Crikey's election studies and opinion polling blog, The Pollbludger, said the polls "are struggling to get young people to respond" and advised aggregating results from several polls to minimise the impact of small sample sizes.

Which polls to use

Dr Economou also suggested aggregating the results of several polls, "in a bid to try and knock out the propensity for each of these polls... to sometimes give deviant results".

He advised examining the results of polls by Newspoll for The Australian newspaper, Ipsos for Fairfax Media, and market research companies Roy Morgan and Essential Media.

He said he takes polls of young voters "with a great deal of scepticism, the samples are too small", but Newspoll was the most authoritative.

"I did note, for example, that when Malcolm Turnbull assumed the leadership from Tony Abbott he actually made explicit reference to Newspoll, so Newspoll I think is the most reputable... with the greatest respect to everybody else."

Mr Bowe advised using the same four pollsters, telling Fact Check that Newspoll and Ipsos are the best and are "as good as each other".

"They are the two polls that are commissioned by big newspapers and that means that they spend the most money on them."

He said Ipsos uses live interview phone polling, which is "the best method", while Newspoll uses a mix of online survey and automated phone polling, where a pre-recorded voice directs respondents to complete the survey by pressing particular buttons.

"While the [Newspoll] methodology isn't as gold standard as it is with Ipsos, they do have a great deal of experience and a very good track record, and Newspoll, rightly or wrongly, is regarded by everyone as the brand you can trust with opinion polling."

Professor McAllister said Newspoll is "more reliable" than other pollsters.

He said "Roy Morgan, Ipsos and all the rest of them" don't have as many respondents as Newspoll's quarterly release, which aggregates data from several surveys.



Newspoll data

All three experts referred Fact Check to the most recent quarterly analysis of Newspolls taken for The Australian during April and May 2016.

The surveys were conducted in all states of Australia and in both city and country areas, with data based on a total of 6,819 interviews among voters.

Among 18 to 34 year olds — the closest age bracket to "under 30s" for which data was available — 38 per cent said their primary vote would go to Labor, 33 per cent to the Coalition, 16 per cent to the Greens and 13 per cent to others.

However, this data was published on May 31, 2016, the day after Senator Di Natale made the claim.

Fact Check assesses claims based on data available at the time the claim was made.

The most recent quarterly analysis of Newspolls available at the time the claim was made used data collected from January to March 2016.

It indicated 38 per cent of people aged 18 to 34 years would give their first vote to Labor, 34 per cent to the Coalition, 17 per cent to the Greens and 11 per cent to others.

Ipsos data

A spokesman for Senator Di Natale referred Fact Check via email to two Ipsos polls as the basis of the claim.

He said the polls "show the Greens vote matching it with other parties amongst young voters".

The first Ipsos poll he referred to was a national survey of 1,402 respondents in total, conducted by telephone from April 14-16, 2016.

Fact Check has set out the data for 18-24 year olds and 25-39 year olds below.



Party

18-24 25-39 Labor 33 34 Liberal-Nat 25 36 Greens 32 17 Palmer United 1 1 Other 9 12

Senator Di Natale's spokesman also referred to an Ipsos poll that surveyed a total of 1,203 respondents nationally and was conducted by telephone from February 11-13, 2016.

Fact Check has set out the data for 18 to 24 year olds and 25 to 39 year olds below.



Party

18-24 25-39 Labor 34 36 Coalition 31 37 Greens 28 14 Independent 5 1 Other 3 13

Both the April and February polls show the Greens were not the most popular party among the 18 to 24 or 25 to 39 categories.

Professor McAllister said these poll results were unlikely to deliver a Greens prime minister under Senator Di Natale's hypothesis.

"How you could say there would be a Greens prime minister I'm not entirely sure, because the Greens wouldn't win the election, they wouldn't get a majority."

Mr Bowe said the results of these polls should not be viewed in isolation.

"[The Greens] almost outdid Labor in the April poll, 33 to 32, but that was their best result."

He said looking at a series of polls shows the Greens will "normally" be "pretty solidly behind" Labor.

Dr Economou said: "I don't trust those polls, they're too small a sample."

Ipsos provided Fact Check with data from its four latest polls on primary voting Iintention for 18 to 24 year olds and 25 to 39 year olds, as at the time Senator Di Natale made his claim.

Fact Check has set out the results below.

None of these polls put the Greens as the most popular party among young voters.

To give an indication of the sample size, the most recent Ipsos poll, as at the time the claim was made, surveyed 1,497 respondents in total, who were interviewed from May 17-19, 2016.

Mr Bowe calculated aggregated data for Fact Check using the six polls published by Ipsos this year.

Out of a sample size of around 900 people aged 18 to 24, he found 36.2 per cent gave their first vote to Labor, 29 per cent to the Coalition, and 27 per cent to the Greens.

Roy Morgan data

Roy Morgan provided Fact Check with data from its last four polls on primary voting intention for 18 to 34 year olds, as at the time Senator Di Natale made the claim.

Fact Check has set out the results below.

The Greens were not the most popular party according to any of these polls.

Morgan Poll Manager, Julian McCrann, told Fact Check: "The ALP is clearly the most popular party for Australian electors under 35."

Essential Media data

Essential Media provided Fact Check with estimates for under 30s first preferences based on its polls from the four weeks before Senator Di Natale made his claim.

It estimated 37 per cent of electors aged under 30 years would give their primary vote to the Coalition, 37 per cent to Labor, 17 per cent to the Greens and 9 per cent to others.

What about preference flows?

Mr Bowe said "it's really difficult" to determine what impact preference flows would have on the final result of an election where all voters were aged under 30.

"If you wanted the most optimistic scenario for the Greens you're saying the Liberals will direct preferences to [them]," he said, as this would enable the Greens to win some seats from Labor.

In this scenario, he said the Greens could "win enough seats that neither major party would win a majority".

"From that kind of obscure, hard-to-say starting point, I think if you have got this even balance between the three parties what you're going to end up with is a hung parliament, and then you're kind of asking a really unknowable question about how those negotiations go because any number of things could happen. The Greens could say to both parties: 'We're in this to be prime minister, we're not going to cut a deal with either of you, but if you want to back us then you're going to have to do it on the basis that we provide the prime minister.' Who knows what would happen in that circumstance but I'd be extremely surprised if either party agreed to that."

Mr Bowe said "there have been a number of times in Tasmania where the Greens have held the balance of power... they have had nearly a quarter of the seats in the Parliament", but they still didn't provide the premier.

He said "based on the numbers we're talking about that the polls are saying, maybe the Greens would get as many as a quarter of the seats in parliament, but that doesn't put them in a position to leverage their way" into the prime ministership.

Dr Economou said the distribution of preferences "really doesn't have much of an impact".

"The majority of people who vote Green give their second preference to Labor, that runs at about 70 per cent. We also know that the number of seats whose result on primary [votes] is changed after the distribution of preferences is usually very small," he said.

Australian Election Study survey

Professor McAllister referred Fact Check to the Australian Election Study survey, which he directs, as another source to use when assessing Senator Di Natale's claim.

The Australian Election Study has been running since 1987 as a series of surveys timed to coincide with federal elections.

The surveys, which have been funded by the Australian Research Council since 2008, are designed to collect data on electoral behaviour and public opinion generally to support academic research.

The most recent survey was for the 2013 election and of all 3,572 respondents, 604 or 16.9 per cent, were aged 18 to 29.

Professor McAllister provided Fact Check with the results to a question asking respondents who they voted for in the 2013 House of Representatives election.

The figures show 38.9 per cent of respondents aged 18 to 29 years said they voted for Labor, 36.8 per cent for the Coalition, 11.6 per cent for the Greens and 12.7 per cent for others.

Sources