Ask Liz MacPherson what she’s most proud of having accomplished in her six-and-a-half years as Government Statistician and she has trouble naming just one.

From making data more accessible to working to modernise the census (despite some severe speed bumps) and increasing outreach to traditionally-overlooked communities, Stats NZ has undergone a sea change with MacPherson in the driver’s seat. That said, it all comes down to the agency’s mission statement: “To unleash the power of data to change lives, which will enable data-led innovation across society, the economy, and the environment.”

“One of the things is that we’ve actually become a lot more open as an organisation,” MacPherson said. “Part of that has been us essentially saying, look, it’s encompassed in our vision and purpose statement which is about ‘unleashing the power of data to change lives’ and about empowering decision-making.

“Ultimately, we’re here to improve the wellbeing of New Zealand and we can’t do that if we’re holding the data inside the organisation. It’s about putting the power in the hands of the people out there who make decisions and opening ourselves up more and more.”

Botched census – but all is not lost

In order to get there, however, the data has to be collated first. Or does it? That’s the question that faced Stats after the bungled 2018 census. In the face of dreadfully low response rates, particularly among Māori, after a botched rollout of a hybrid digital/paper census, the organisation has worked to bolster its census results with so-called administrative data – information from other agencies that can answer the same questions the census asks.

Only 83.3 percent of the population responded fully to the 2018 census, far below not only Stats’ 94 percent target but even the bottom line for reporting reliable data. A damning independent review into the census shows that these numbers grew worse for traditionally under-represented sub-groups and led to MacPherson’s resignation.

Just 68.2 percent of Māori responded fully, down 20 percentage points from the 2013 census. Asians saw a 10 percent drop to 81.7 percent, Pasifika a 23 percent drop to 65.1 percent, and youth a 13.5 percent drop to 75 percent. The 2018 goal for each of these groups was 92 percent, already a step down from 2013’s 94 percent objective.

All is not lost, however. Administrative data will fill the gaps, allowing Stats NZ to report census results that it considers reliable. This isn’t just a contingency plan either – many overseas statistics agencies use administrative data alongside or instead of their censuses and New Zealand has long been moving in that direction.

In essence, MacPherson says, there are three types of census that international bodies see as legitimate. Enumerated censuses report results from a direct count and interaction with the population, whether in person or online. On the other side of the spectrum, many Scandinavian countries use national registry systems to report census data without a serious counting effort. Finally, there are countries in the middle, which combine an enumerated census with administrative data to glean new or more accurate findings.

New Zealand is in the middle but Stats NZ has long had an overarching goal of transitioning from the enumerating side towards the administrative end.

“The direction of travel for censuses generally, certainly in the countries which we usually benchmark ourselves against, is for an increasing use of administrative data. It is getting harder to get good response rates, or at the very least, it’s getting harder to get high response rates without spending a lot of money,” MacPherson said.

“Most national statistical offices are looking at the use of administrative data in the same way we have been and also moving, if they weren’t already using online, moving to use online aspects of their census. So I think what you’ll see in the future is a combination of those things.”

Fundamental to democracy

In a time when society is increasingly described as post-truth, when political parties are accused of engineering misleading graphics, how important is it to have an independent agency setting our a common set of evidence to base debate on?

“My view is that Statistics New Zealand is a fundamental part of our democracy, actually,” MacPherson said. “You could almost say that it has a constitutional role, in terms of providing that independent and impartial information that New Zealanders can use to make decisions about our future.

“I take really seriously the use of statistics and data and, in particular, when it’s used in a misleading way. I have commented in the past in situations where I think data has been used that way.

“At the very least, what we have been talking about here at Stats NZ is making sure that some of those key hot topics, things that people are really focused on, that we have very clear factual information on them available on our website so that people can actually see what the real data is on the issues. The hope then is that stakeholders – be they the government, other politicians, political commentators, the media and others – will actually use that data when they’re making statements.”

MacPherson also referred to the United Kingdom’s Office for National Statistics, which writes to political parties at the start of each election system warning them against misusing data. If the agency sees misleading data anyways, it will strive to correct the record.

The same could be done in New Zealand but MacPherson won’t be making that call: “I will be leaving to my successor to think about whether they pick up something similar.”

Population a particular focus

One of the most significant statistical projections that Stats NZ puts out is its batch of population figures. As New Zealand’s population continues to swell, population and migration numbers are increasingly important to businesses and policymakers alike.

“Our recent census showed that it was one of the strongest periods of population growth ever. And in that particular case, two-thirds of that was due to migration and one-third natural increase,” MacPherson said. “Our net migration rate is around 11 people per thousand, per year. Our annual net migration has been around 56,000 for a while now. We’re approaching five million.

“If we are in a historically high period, then effectively we’re forecasting off a base that is changing for us. But I think the key thing to focus on is, when we do do our projections, they are based on, what is essentially population accounting. One of the things that makes it easier for us is that people have to cross a body of water to get here, they can’t just cross a line on a map.

“We do have accurate information about who’s coming into the country and who’s leaving the country. We know about who’s been born and who dies. That’s what we do our population accounting based on.

“We provide to New Zealanders various different scenarios – low-, medium- and high-migration – and provide advice to them on where we think they should be thinking about pitching things. But, given we’re operating in historically high levels of migration and that migration is having so much of an impact on us, it’s hard to know exactly where that’s going to go in the future.”

Marc Daalder is a senior political reporter based in Wellington who covers climate change, health, energy and violent extremism. Twitter/Bluesky: @marcdaalder

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