Please improve immigration data, not undermine it

On her visit to Australia, the Prime Minister has been quoted as suggesting that departure cards might soon be discontinued, and that she will be pursuing her Customs and Statistics ministers on the matter.

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.

I wrote about this a few months ago when, under the previous government, Statistics New Zealand publicised the possibility/likelihood of departure cards being discontinued.  At the time, SNZ suggested that

“In the near future, the outcomes-based ‘12/16-month rule’ is expected to become a key component in how we determine the number of migrants in New Zealand.”

The “12/16 data” are the new series of permanent and long-term movements derived by lining up, using passport details, people coming and going, and waiting until more than a year after the initial movement to see if the movement loooks permanent or long-term.    It is all very interesting – I’ve praised SNZ for putting the collection in place –  and provides a more accurate measure of actual long-term comings and goings than the (stated intentions based) arrival and departure card.   But it is only available with a very long lag  (ie more than 16 months), whereas the existing PLT data are available monthly, with a few weeks lag (and in principle could be produced even more frequently).

I’m reproducing here the concerns I expressed in September

I’ve explained here previously why the resulting PLT data has its limitations.   It isn’t a good basis to use to look at immigration policy itself.  Approvals data from MBIE is better for those purposes –  and would be better still if they made the information available in an accessible format on a more timely basis.     And the PLT data are based on self-reported intentions, and intentions aren’t always what people end up doing.  Some people think they are leaving permanently, and are back six months later, and vice versa..   But intentions data isn’t nothing either  (just as business surveys capture intentions/expectations and things don’t always turn out as they expect).    The patterns –  and especially the cyclical patterns, the turning points –  in the PLT data tend to match those in the (lagged) 12/16 data quite closely.

There are quite enough gaps (and long lags) in New Zealand economic data as it is –  monthly CPIs, monthly manufacturing data, quarterly income measure of GDP just for starters –  that I’m just stagggered that key economic agencies are apparently willing to let SNZ/Customs go ahead and consider dropping departure (and arrival?) cards.  Where are Treasury and the Reserve Bank on this?

How, specifically, does it matter?   Without departure or arrival cards we would, of course, still have immigration approvals data for most non-citizens (other than Australians).  In principle, they could be published weekly or monthly with just a day or two’s lag, and be available in quite accessible formats.  Since approvals lead actual arrivals, there is certainly useful information in those approvals numbers (it is just that they aren’t made easily available now).

We could presumably also have data on the total number of people crossing the border (gross and net) from passport scanning.   I’m not aware that those numbers are published at present, but they could be.  And presumably they could be broken down by nationality (or at least by the passport the person happened to be travelling on).    That would be useful –  relative to having no arrivals or departures data –  but not very.   If you look at total net arrivals or departures (or net) data it is enormously volatile, and thrown around things like Lions tours –  in other words, holidaymaker and other short-term visitor numbers swamp movements of migrants.   Using that data alone, we’d have no ability to pick turning points for some considerable time after the turn had already happened.

The gaps would be particularly serious for the movement of New Zealanders, and more than half the variability in the 12/16 measure of net migration has arisen from fluctuations in the movements of New Zealanders.  We would have no secure way of knowing if someone leaving was planning to be off for a week’s holiday, or intending to stay away for ever.  The 12/16 method would eventually tell us what they did –  but there is a lag of almost 18 months on the availability of that information.    And even if the new plan involves keeping arrival cards and only getting rid of departure cards, most of the variability in New Zealanders’ migration movements is in the numbers leaving, not the numbers arriving.

Less importantly, without the departure cards we would seem likely to lose the ability to analyse migration (including reflows outwards by migrants who become NZ citizens) by the birthplace of the migrant.

Perhaps someone has done a robust cost-benefit analysis on getting rid of departure (and arrival?) cards.  If so, I would be keen to see it, and particularly keen to see how the relevant officials have factored in the loss of some of world’s best migration data to macroeconomic monitoring and forecasting, in a country with some of the most volatile immigration flows in the advanced world (and not a great track record of getting monetary policy, or housing markets, right as it is).  And even if one sets aside the macroeconomic analysts interests, it is not as if net migration numbers are one of those issues of no political salience at all.  Put an 18 month lag on decent data, and you risk not silencing debate – which some might wish for – but allowing all sorts of misconceptions and concerns to flourish, which no one will be in a position to allay.  It would, frankly, seem crazy.    Immigration has a economic and political salience here which it might not have in a country with land borders and small permanent inflows/outflows.

Frankly, it looks like a pretty irresponsible proposal.   The departure cards provide the only information on what New Zealanders are doing, and the comings and goings of New Zealanders are a big part of the PLT migration story (and aren’t, of course, under government control).

And in case anyone thought the PLT numbers were simply flaky measures, with no information

…here are the total net flows on the two measures [12/16 in blue, PLT in orange]


They don’t match up perfectly –  one wouldn’t expect them to, and there is information even in the differences (eg what led people to change their plans) –  but no analyst would happily give up a series that provided a 17 month lead this (relatively) good on the 12/16 series.

Turning points matter a lot for macroeconomic analysis and monitoring, and the turning points in the two series are very similar.

The claim from Statistics New Zealand is that they can fill the gap with estimates that

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 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.

And talking of data gaps, I’ve also written here before about the very long lags in MBIE making available, in readily usable form, the summary administrative data on actual immigration approvals (and estimates of the stock of migrants).   Some of the data you can get yourself, if you don’t mind manipulating spreadsheets that are hundreds of thousands of lines long, but for most people, for practical purposes, the data are really only available annually, and typically with quite a long lag.    That is really inexcusable.  Like it or not, immigration policy is a major instrument of government economic and social policy, and approvals data (and associated stock estimates) are a valuable part of informing the public debate.  Information is almost always better than no information.

[UPDATE: A reader highlights that not even the spreadsheets are currently available.]

MBIE publishes the summary results, and accessible tabular data, in their annual Migration Trends and Outlook publication. In many respects, it is a very useful publication, even if (a) the data are only annual (whereas, say, building approvals data are available monthly), and (b) the publication has a minimum lag of 4 to 5 months (in other words, data for the full year to June 2016 was only published in late November 2016).  That isn’t remotely good enough, especially for administrative data.  Neither MBIE nor SNZ has to collect the data –  it all sits in MBIE’s own systems, generated every single working day.  There is no obvious reason why the data  – all the summary data (number of approvals in each category, occupation, age, sex, country of origin etc) –  couldn’t be made accessibly available monthly within a few days of the end of each month.

I’ve made these criticisms previously.  And that was when Migration Trends and Outlook  was coming out on its normal slow timetable (a 5 to 17 month lag).   But go to the MBIE website looking for the 2016/17 publication –  in March 2018 –  and it still hasn’t been published, more than eight months after the end of the year in question, 20 months after the start of the period to which the data would releate.

Some readers might be inclined to suspect MBIE of some deliberate strategy to keep the information from the public.  I’m not.  That is not only because I’m not naturally a conspiracy theorist, and have had plenty experience of the failures of bureaucracy. It is also because a few months ago I was invited to a meeting by an MBIE official who was part of a team working on improving the Migration Trends and Outlook publication, looking for my comments/ideas on data, immigration research etc  The official seemed quite genuine, and enthusiastically told me of the efforts MBIE was putting in to improving the publications, and (if I recall rightly) the timeliness of the data (even while stressing that it was quite hard and there were “systemss issues”.  That meeting last year would have been before the usual publication data of the Migration Trends and Outlook publication, so I came away from the meeting quite encouraged.   I’m still quite willing to believe that MBIE has the project in hand, but in the meantime……where is the 2016/17 data?  It is now March 2018.