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.