4 million, 5 million, 6 million ….?

Monday August 21, 2017 Mark Cox

Shortly after I arrived in the country early in 2003, Statistics New Zealand announced that the resident population had reached 4 million.  And, who knows, I might actually have been number 4,000,000.

However, the same announcement stated that the population was unlikely to reach 5 million, unless the country’s birth rate or net migration increased.  The population was expected to peak at 4.81 million in 2046.  It was then expected to fall as the number of deaths of baby boomers reached a peak, without their grandchildren breeding fast enough to replace them.


Coincidentally, the Statistics New Zealand’s population clock currently stands at just about the 4.81 million number mentioned above, with the number increasing by one new resident every 6 minutes and 39 seconds.  At this rate, the population is likely to reach 5 million sometime in early in 2020.   

Moreover, Statistics New Zealand’s most recent projections suggest that the population will be about 6 million in 2046, and will continue increasing after that date.


The question arising is: why have the projections changed so dramatically in a comparatively short time?

Population change is driven by two main forces: natural increase, which is the number of births less the number of deaths; and net migration, which is the number of permanent and long-term immigrants less the number of permanents and long-term emigrants.


As the graph below indicates, the natural increase in the population has varied relatively little during the past 25 years; with a minimum of 26,235 in 2002, and a maximum of 35,961 in 2008.  The number of births has varied by about the same amount, but the number of deaths has shown little year by year change.


graph 01


On the other hand, net migration has shown much more variation; from an outflow of 11,369 in 1999, to a maximum of 69,090 in 2016.  However, it should be noted that these are calendar year figures, and that net migration in the year to July 2017 was 72,400.  This compares with Statistics New Zealand’s assumption for its median (i.e. most likely) population projection that annual net migration will average only 15,000 over the longer term.


graph 02


The significance of high net migration is that it could easily cause the number to births to start rising, because permanent migrants tend to be of child-bearing age.  The peak age for migrants arriving on work visas is in the late 20s, while the peak age of migrants arriving on residents visas is in the early 30s.


Overall, therefore, the chances are that the next set of national projections (not due until late 2019) will show the population reaching 6 million sometime in the 2030s, and 7 million sometime in the 2040s.