Do We Need a Population Census?

‘It has been said that figures rule the world. Maybe. I am quite sure that it is figures which show us whether it is being ruled well or badly.’ Goethe

I was struck at a recent conference on equity for the elderly, how many presenters implicitly relied upon Statistics New Zealand. We take SNZ for granted. Had it been drawn to their attention, many users would have been astonished. This is not just true for economists, but as the conference showed, it is true for social issues as well across a wider group of professions and thinkers.

Underpinning the SNZ’s work is a comprehensive data base of every New Zealander. Our data base comes from a five-yearly census of population and dwelling. The last was held in 2023; the results are to be released in August.

I am aware more than most of the value of the censuses. Economic data in the nineteenth century is scarce, so when I was working on an economic history of New Zealand I had to pay close attention to the population data. In the twentieth century, censuses were not held in 1931 and 1941 because of depression and war. We have no official estimate of how much unemployment there was in the Great Depression and we have only the vaguest idea of women’s contribution to the domestic war effort.

More recently, the 2018 census head count was poor. The statisticians in SNZ made a valiant effort to improve the unsatisfactory results that the incompetence of those administrating the count, but about once every month or so I meet an issue where I cannot trust the 2018 estimates, and those from the more reliable 2013 census are out of date – in fact I am usually trying to trace a post-2013 social change. Ah, you say, now we have sample surveys, but their reliability depends upon a comprehensive data base and they do not have the same detail and coverage.

SNZ is exploring whether they can make greater use of administrative data even to the extent of abandoning the regular census next due in 2028. A properly done census is very expensive. The 2023 census cost more than $300m. (The administrators tried to do the 2018 census on the cheap and we still suffer from the shoddy job.) Arguably, we could save a mint by using administrative data.

Does that mean we have an official population register? No, but almost everyone turns up in various official data bases and it is possible to meld them together to get a picture of each of us. SNZ, who does the melding, has strong statutory privacy restraints (as well as a professional ethos) that protects the public from turning this into an official population register. (Social statisticians such as those at SNZ are actually not very interested in the individual records providing they are comprehensive and accurate, because typically we are looking for patterns in the data.)

I would be very uneasy if the government knew as much about me as I disclose in my census return. The Census is double protected. As well as the general provisions in the Statistics Act there are additional protections for the Census. There have been famous occasions when the Government has wanted to use the Census as, in effect, an Official Population Register and Government Statisticians, bless them, have told politicians to go to hell, although more politely. (If SNZ could create an Official Population Register, then another government agency with fewer scruples could do the same. It would be far more interested in individuals.)

Additionally, there are issues which we need to know about for social purposes where the official data coverage is poor: disabilty, ethnicity, fertility, household composition, internal migration, religion and voluntary work, for instance.

We have no idea how reliable administrative data are for the purpose of a foundation data base.   We shall have a better idea following a comparison with the 2023 Census results but the study will take time and we need to make a decision about the next Census before it is done. In the interim, we should be reluctant to rely solely on administrative data bases.

What if the administrative data base proves inadequate? It would be a repeat of the 2018 Census in which a new system was tried, found wanting and there was no back up. Those of us who depend on quality statistics would be even more stranded – that is everybody.

Apparently the 2023 enumerators – those who knock on our doors – were subject to unusual levels of abuse. We do not know whether that happened as much in 2018 because the enumeration was outsourced and gave less feedback, but the abuse – some of it very unpleasant – was markedly higher than during the 2013 enumeration.

The reasons might include increasing social fragmentation, perhaps compounded by extraneous events like the turmoil from Covid. That is for a later conversation, which needs to be held. (If it is at all analytic it will be using data based upon SNZ statistics.)

I hardly saw any publicity; apparently it was targeted on others. (To make a confession, in the 45 years of writing this column, I have always written one about census time, explaining some facet of it as a small contribution to public understanding. The 2023 census was an exception, because it crept up on me without any of the usual alerts.) Perhaps there were people who resented the knocking at the door, because they did not understand it was about making a contribution to running the country. That is what a census means. If you are not counted, then you are likely to be ignored when policy decisions are being made.

That leads to a wider issue. The public profile of Statistics New Zealand is diminishing. Once a teacher would refer students to the New Zealand Official Yearbook in the school library. There has not been a yearbook since 2010.  I doubt nowadays that most school libraries have any printed material published by SNZ so the students don’t get that appreciation of it’s role. Yes, there is an SNZ website, which is invaluable for someone like me who uses it almost daily for a wide variety of issues. So complicated and rich is SNZ’s work, that the newbie faces a maze. I do too, but I’ve learned how to find my way through it (usually – sometimes I have to ask).

On every business page there are references to official statistics or analyses based on them. Other news stories do not feature population-based statistics so often, but they are there. However, the vital role of SNZ in the development of these stories rarely gets noticed.

Perhaps SNZ should be raising its public profile. I am not saying it should be as explicit as in Goethe’s: ‘it has been said that figures rule the world. Maybe. I am quite sure that it is figures which show us whether it is being ruled well or badly.’ But SNZ needs to convey to the public the task it is doing. It could do this with hard copy publications, a separate public friendly website (like Te Ara), and the Government Statistician taking a more prominent public role, promoting and defending the integrity of the statistical system. A former Government Statistician was unwise to dismantle the SNZ advisory system which generated a cadre of informed expert defenders of SNZ.

SNZ especially needs to guard against being seen as just managing the statistics for the government. It is managing them for the public too. You may have observed that the government spending cuts have been more directed at cutting services to the public and less to cutting services to the state. Focusing on administrative data and abandoning the census could be seen as symbolic of this narrowing remit; hopefully that is not Statistics New Zealand’s intention.