Pottering around between children’s orthodontic appointments and the start of the cricket, my eye lit on the Herald’s editorial on a various issues/problems relating to immigration.  These are, we are told, “problems” we are fortunate to have, contrasting favourably with current situation with that a few years ago. Among others things, we were enjoined to remember that:

“This country’s population barely grew during the last quarter of the 20th century”

Actually, our population in 1975 was 3.083 million, and in 2000 it was 3.858 million, an increase of a mere 25 per cent.  Over the same period, the United Nations population database tells us that high income countries in total experienced a population increase of 20 per cent.

One thing led to another and I decided to dig out the data on the regional patterns of net PLT migration.  I’d recently used the (common) line that about half the migrants come to Auckland, while Auckland has about a third of the population, but I’d never looked at the data myself.

The data aren’t ideal.  The PLT numbers are based on self-reported intent at the time of arrival/departure, and we know that at times even in aggregate they can differ from the actual realised experience.  Census numbers might be better for longer-term trends, but we only get that data every five years, and it is now four years since the last census.  So, the PLT data are the one set of numbers we have that allow us to distinguish New Zealand citizens from others (only the latter  are a matter of immigration policy) and provide breakdowns by regions within New Zealand.  And Statistics New Zealand has this breakdown all the way back to 1991, around the time broadly the current approach to immigration policy was adopted.

What do they show?

Often people compare the flow into Auckland with the overall net inflow, but within those net inflow figures quite a lot of people don’t state where in New Zealand they have come from or, if arriving, where they are planning to stay.  Among non-citizens, in calendar 2016 there were a net 14000 of those people, of a net inflow of 72406.  It is probably more reasonable to compare the net inflow to any particular region  to the overall inflow of those who stated a place of residence (perhaps a reasonable assumption is that those who didn’t state were representative of those who did, but presumably no one knows).  Here is the net PLT inflow of non NZ citizens to Auckland, for each year since 1991, as a share of the identified net inflow.

Over the full 26 year period, 59.1 per cent of the net inflow of non-citizens was to Auckland.  It dipped for a while during the 2000s but in the last five years or so seems to have returned to around normal.  And before anyone interjects the word “students”, yes we know that students disproportionately come to Auckland, and we know that most of them eventually leave again.  But these are net figures, and there is nothing unusual about where things stand now in terms of the share of the non-NZ flow that has been coming to Auckland.

And what about New Zealand citizens?  Every year since 1991 there has been a net PLT outflow of New Zealand citizens from Auckland.  Some years, the net flows of New Zealanders are quite small –  last year only a net 1818 New Zealand citizens left New Zealand –  so the regional shares can swing around quite a lot.   Last year was especially notable –  a net 2836 New Zealand citizens left  Auckland for abroad, more than the outflow of New Zealand citizens for the whole country.

But over the 26 years as a whole, 37 per cent of the net outflow of New Zealand citizens has been from Auckland.    Last year, Auckland’s population was around 34 per cent of the total New Zealand population.

Broadly speaking then, New Zealanders (net) leave the country pretty evenly across the country.  They are perhaps a little more likely to leave from Auckland (given that Auckland has a larger share of the non-citizen population) than from other places –  and that is consistent with the Census data which has found that net people seem to be moving out of Auckland for other places in New Zealand too – but that difference seems fairly secondary. But the non-New Zealanders who come to New Zealand (net) come overwhelming to Auckland.

Out of curiosity I put the two together.  I was a bit reluctant to do so, since what New Zealanders do isn’t a matter of immigration policy at all.  But for some purposes –  housing is notable example – both matter, because it is the combination that affects demand for accommodation.

From year to year, the share has been hugely variable  (mostly because of the variability in the net outflow of New Zealanders).  But with all the caveats that surround the PLT data noted, and recognising that over 26 years there was a net inflow of 162594 people (NZers and others) who didn’t specify a location, the Auckland share of the net inflow of the people who did specify a location was, on this measure, 98.1 per cent.

I found that pretty staggering.  Perhaps it isn’t surprising that land use restrictions run head on into this net inflow to produce in Auckland some of the highest house price to income ratios anywhere.