Natural increase and migration

Recently I noted that the population estimate for New Zealand was currently registering a total of 4.4 million people, which is a far cry from the 'traditional' figure I remember from my youth, which held that New Zealand had a population of three million. You still hear people use that three million figure today, even though it's woefully out of date - it just seems to have stuck in the national psyche: one million during WW1, two million during WW2, and three million after that.

I decided to take a look at how the overall population growth figures are changing. Following a delve through the Stats website trying to hunt down historical data, I decided to limit my search for information to recent years. So here's a look at how the New Zealand population has been growing in the early years of the 21st century (March annual figures):

Source: Statistics NZ

The rate of population growth from natural increase (the difference between live births and deaths) has remained rather static, although the numbers have risen from around 30,000 at the turn of the century to around 35,000 in 2011. But net immigration has fluctuated much more widely, showing the fluidity of modern population movement, which often follows changing economic conditions in New Zealand or overseas.

For the first three years of the table above, New Zealand experienced a net population loss from migration. This was offset by natural increase, but ultimately meant that the national population grew slowly from 1999 to 2001. This was followed by a reversal and three big years of net migration to New Zealand, perhaps partly spurred by the 2001 terrorist attack in New York. In 2002 and 2004 migration contributed nearly half of New Zealand's total population growth, while in 2003 it contributed even more, at 60 percent.

Over the past seven years years net migration decreased to between five and ten thousand people per year, with the exception of a temporary leap to twenty thousand in 2010. This has meant that in recent years New Zealand's population growth has been largely driven by natural increase, with an average of 22.8 percent of population increase derived from migration, with the remaining 77.2 percent of the increase caused by natural increase.

While New Zealand still struggles to construct sufficient new dwellings to house its expanding population, at least the patterns of population growth in recent years have been more consistent than in the earlier part of the century, making planning a little easier.