Tossing away valuable emigration data

We had confirmation yesterday that departure cards are to be scrapped.    This was flagged by the Prime Minister a few months ago, and I wrote about the issue here.   Since then it appears that there has been no proper public consultative process.

As I noted in March

I’m sure airlines and airport operators hate the cards.  There have been prevous efforts to get rid of them.  They are, nonetheless, a core element of the data collections (in conjunction with arrivals cards) that give us some of the very best immigration data anywhere.  In a country with –  year in, year out – some of the very largest immigration, and emigration, flows anywhere in the advanced world.

We are told by the government that this brings us more into line with other countries

On Sunday, Lees-Galloway said the move would bring New Zealand into line with other countries, few of which had departure cards with the level of detail required by the New Zealand card.

(although even then we appear to overshooting in scrapping the cards completely).

But the statistical and related policy issues New Zealand grapples with are different from those in many other countries, most of whom don’t have big outflows of their own citizens, or big cyclical fluctuations in those flows.     Immigration of non-citizens is managed through the administrative approvals required to get a visa.  But people don’t need government approval to leave again and New Zealanders (of course) are free to come and go without any prior approval from the New Zealand government.

So departure cards captured the intentions of people coming and going.  Those stating that they intend to have changed countries for 12 months or more make up the permanent and long-term migration data that, for decades, has been a major and very timely indicator of what is going on, in a country with some of the largest swings in net migration of any country in the world.   It isn’t as perfect indicator by any means –  very timely ones rarely are – but it has consistently contained valuable information, especially around turning points.   And now the government proposes to scrap this data collection.

The Minister of Customs reckons the cards aren’t necessary

Customs Minister Meka Whaitiri said the cards were no longer needed for their original purpose – to account for all passengers crossing the New Zealand border.

“We have smarter systems now that capture passenger identity information and travel movement records electronically,” she said.

“Information captured by the departure cards is now mainly used for statistical purposes.

“Statistics NZ has developed an alternative way to produce migration and tourism statistics, based on actual movements rather than passengers’ stated intentions on the departure cards.”

I certainly agree that departure cards aren’t needed to capture the total flows, but it is the timely breakdown of that data that has been extensively used for decades.   And the operative word there is “timely”.  The new 12/16 method data –  looking back and seeing how long people were actually here/away – is better for long-term analytical purposes, but it is available only with a 17 month lag, whereas the departure card based data is available within weeks.  That difference matters, and it is worth bearing in mind that 17 months is almost half a parliamentary term.

We are told that Statistics New Zealand has “developed an alternative way to produce” the data, but we’ve seen no details of this, and there has been no consultative document made available for comment.  In  my earlier post I included this quote from SNZ claiming that in future estimates of the PLT breakdown

will be generated through a probabilistic predictive model of traveller type (ie short-term traveller, or long-term migrant), based on available characteristics of travellers. Such a model will provide a provisional estimate of migration, which we can then revise (if required) as sufficient time passes for us to apply the outcomes-based measure.

I commented then

I hope that they plan to rigorously evaluate the accuracy of such models, including when they’ve worked well and when they haven’t, and how well they capture the effects of policy changes, and that they expose their models and evaluation to external scrutiny before scrapping such a valuable source of hard data as the departure card.

But we have seen no sign of such an evaluation at all, and yet in a few months that data that have been used for decades will be discontinued, with  no ability to recreate it in future if the new models that are talked about prove not to have been very good.

Without seeing the models it is hard to comment on where they might go wrong.  But the key point is that statistical models often work fine when past behavioural patterns keep on as they were in the past, and they often fail when behaviour changes.   It is the behavioural changes that are often of most interest to the analyst, and it looks as though there will now be very long lags before we have the data to enable any such changes to be recognised.

I just heard Iain Lees-Galloway claiming on Radio NZ that future statistical information will be improved by scrapping the departure cards.  That seems very unlikely – essentially impossible, because you cannot really know the intentions of travellers other than by asking them, and intentions actually matter in this business.

I could add to the lament around official immigration statistics that there has still been very little progress in making available regular, timely, seasonally adjusted, accessible data from MBIE on visa approvals.  These are major economic and social data for New Zealand, which should be readily available almost instantly, including through SNZ’s Infoshare site.  There is no reason why immigration approvals data should not be at least as readily useable as, say, building approvals data. I know MBIE has a project underway to improve the situation, and make available an immigration data dashboard, but it seems to be moving very slowly –  it must be a year now since MBIE first told me about it, and it is months since the person doing the work invited me to provide comments on a prototype.  It is encouraging that something appears to be in the works, but in the meantime we limp on with inadequate, not user-friendly, administrative data, while the government simply abandons the best timely data we have on what people leaving New Zealand are planning to do.




20 thoughts on “Tossing away valuable emigration data

    • Yes, I just saw that Herald story now. Sounds extraordinarily incompetent – and not actually great journalism either as there was no attempt to get a response from the Minister or even MBIE senior mgmt.


  1. “”Iain Lees-Galloway claiming on Radio NZ that future statistical information will be improved by scrapping the departure cards. That seems very unlikely – essentially impossible, because you cannot really know the intentions of travellers other than by asking them, and intentions actually matter in this business.””.

    It doesn’t seem impossible to me. I’ve always assumed many filling in the cards just scribble in whatever is easiest not a careful analysis of their intentions. So summaries of the departure card data will be fuzzy. Standard statistical analysis of sample data may well be more accurate. However if Mr Lees-Galloway claims he now has better data he should be able to show how it is better. For example do all the builders going to Australia planning to work there permanently actually stay when they experience sunburn and snake bite and Australian culture? Maybe many are unable to find the pot of gold and return within weeks? Lets compare the old and the new stats and note the differences.


    • Given that we have to hand these departure cards to a Customs officer who do ask questions makes it more likely that you do fill these out correctly as best as possible. I think they are more accurate than not. Also having been subjected to a number of so called random(feels more like profiling ie older guy with young travel companion), the extra scrutiny for contraband does also instill the fear that calls for accuracy when filling out any forms at border control.


      • More accurate than not would permit 49% to be plain wrong. Entry forms I agree.
        Departure forms – you are flying to London via Brisbane, Singapore and Paris with various intervals between flights so what do you fill in for where are you flying to?
        I take a contract to work in PNG for 5 years but will fly back to NZ to visit family when I’m on holiday – is that away for 11 months, 1 year or permanently?


      • The same problems would be with the arrival cards so we might as well do away with those PLT stats as well other than the contraband sections.


    • Historical experience (eg comparing the PLT numbers with the 12/16 method numbers) suggests that the recorded intentions data have been meaningful, including in highlighting turning points (a key concern of macroeconomists).

      After my post went out, late this morning SNZ announced that they will release more on their new methods tomorrow. I will be interested to take a look.

      (Sample surveys won’t be an improvement here as it is very difficult to define the appropriate “population” from which the sample would be drawn – and could be quite time-consuming for the poor travellers waylaid at the airport for answers.)


  2. For over a year this message on the govt immigration stats webpage:-

    “”Statistics files for download
    For privacy reasons the CSV files have been temporarily removed from the website. The decision follows concerns raised that some information previously published has breached individuals’ privacy. INZ has removed the files for the time being while we review how we provide this information in a way that ensures INZ meets its legal obligation to protect personal information.””

    I used to enjoy checking this database. For the life of me I cannot see how personal info can be deduced from it so I’m baffled by the phrase “breached individuals’ privacy”. Given today’s info about law breakers being ignored by MBIE because they haven’t got the cash to process a deportation maybe that explains why they can’t find the 30 mins needed for a computer programmer to change the database so it can be republish monthly as it was in the past. Note several subsets are published as PDF files. Makes it far harder to check trends such as the apparent bias pro-Chinese and anti-Indian that applies to investors.


  3. Old-time convention is for the new system to be run in parallel with the old system for some months, conducting sensitivity tests that co-relate the two systems, establishing that the new system produces better granularity. Obviously they can’t replicate the 12/16 system with 17 months delay.

    This is 2018. The arrival of this new approach is at least 15 years late. And remember 20% of arrival cards and departure cards are incomplete, and significantly, accepted by customs in that state.

    The ultimate test of the new system will be if it can identify and quantify the number of so called “kiwis” travelling to Australia on newly minted NZ passports by newly minted “citizens”

    Liked by 1 person

    • Well if they arrive in NZ as PhD students and we subsidise their studies and say 7 years later they are Kiwi citizens and experienced engineers, professors, surgeons then I’m sure Australia will delighted to take our newly minted citizens because where ever they originated they will now be trained to NZ standards and fluent in English. On the other hand they may prefer to wait seven years for our experienced builders originating in the Philipines who are willing to work for peanuts and live four families to a single house.
      My suspicion is Australia will be distrustful even if they only received Nobel prize winner newly minted Kiwis and the Australian govt will show zero toleration and suddenly require all Kiwis to obtain visas just as we require Pacific Islanders to jump through hoops to visit NZ.


  4. Australia’s longstanding concern has been about the Pacifc quotas people – who don’t (almost by definition) reach our skills thresholds (and Aus has no similar category). Also those from Cooks and Niue (the latter two groups both NZ citizens anyway).

    I wrote about this issue, and some numbers, here and


    • Cooks population is only 17,000 and Nuie is 1,600 so I doubt Australia is really bothered by them. Tonga with 100,000 and Samoa with almost double that may be of greater concern. So long as Australia wants to be a great Rugby nation (League or Union) they will need all the PIs they can find. Same applies to NZ.


    • I suspect there are relatively efficient ways to link this to technology like smart gate (program in a quick question or two), or maybe use airline information about the nature of the tickets people are travelling on. 6.8 million bits of paper to understand the intentions of a few tens of thousands does seem unnecessary to me. And then we found out on the news last night that once collected the cards are manually sorted by flight number, and then “verified”. That’s where the cost is!

      On the other hand the use of “100,000 hours or 12 years” was just rubbish justification. 100,000 hours and 6.8 million cards is less than a minute per person. I suspect most take a bit longer than that, but it’s never more than a minor impost. Better from a passenger efficiency point of view to follow Australia and allow e-boarding passes to be issued for on line check in so you don’t have to wait have an airline person check that your passport is your passport.


      • Yes, I’m not wedded to the technology. It is the information that matters. But it would be considerably more reassuring if the SNZ new method had been run live in parallel with departure cards for a year or two before decisions to scrap the actual universal data collection was made, rather than (as seems to be the case here) the industry gets its way and SNZ is left scampering to come up with something to replace a longstanding data source that is about to be scrapped.

        But perhaps the robustness of the new SNZ method, and all the backtesting they’ve done, identifying all the potentially problematic areas etc, will surprise me.


  5. I have never understood why people who – correctly – want to see less governemnt intervention, are often the greatest supporters of the surveilance state … Surely it’s none of the state’s business unless they have good reason to believe a crime is about to be committed?


    • It is a reasonable point, and had the data collections never been put in place I might well argue against commencing them. But as they have been around, and very useful for practical policymaking, and the govt isn’t making the case that we don’t need/want the data any more, good process should demand consulting on, trialling ,and parallel-running a new, less intrusive, system before just scrapping the old.

      And this is SNZ we are dealing with, the organisation that stuffed up the latest Census, surely the core product they are responsible for.


  6. Did Jacinda Adern just admit our immigration policy has been a a failure?

    Will the Fire Brigade put the fire out?

    Latest migration figures show more people left New Zealand than came to settle in the last year. Massey University Demographer Professor Paul Spoonley discusses the impact on the economy and business confidence?


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