Statistics New Zealand's 2011-base projections indicate that a population of 7 million by 2061 is unlikely, given current and assumed future demographic trends. The likelihood is estimated at 1 chance in 25.
The median projection (there is an estimated 50 percent chance the population could be lower, and a 50 percent chance it could be higher) is a population of 6.0 million in 2061. The median assumptions for this projection are:
How could we do it?
Higher than the assumed fertility, life expectancy, or net migration could allow our population to reach 7 million by 2061.
More people come to stay and fewer leave
Given the median fertility and mortality assumptions above, we need to average a net gain of 26,000 migrants a year during 2013–61 to reach 7 million by 2061. Although annual net migration has exceeded 25,000 occasionally, New Zealand’s external migration balance has also fluctuated widely, with several periods of net migration loss.
Women have more children
Alternatively, our population could reach 7 million by 2061 if women averaged 2.1 births each and net migration averaged 20,000 a year. Only occasionally in the last few decades have fertility rates reached that level, although in 2007–11 they were at or above that level.
People live extra-long lives
New Zealand's population could also reach 7 million by 2061 if women averaged 2.1 births each and life expectancy at birth increased to 95 years in 2061. Net migration needs to average 16,500 a year under that scenario.
Fertility has strong effect
If fertility and life expectancy were both very high (women averaged 2.5 births each and life expectancy at birth increased to 95 years in 2061), net migration of 7,000 a year is sufficient for our population to reach 7 million by 2061. The scenarios highlight that fertility levels have a large impact on future populations.
| Annual net migration required to reach given populations |
|
Population in 2061
|
Total fertility rate in long term
(births per woman)
|
Life expectancy at birth in 2061
(years of life)
|
Required annual net migration
2013–61(1)
|
| 7 million |
1.9
|
89.3
|
25,900
|
|
|
2.1
|
89.3
|
20,100
|
|
|
2.1
|
95.0
|
16,500
|
|
|
2.5
|
95.0
|
6,900
|
|
| 10 million |
1.9
|
89.3
|
68,600
|
|
|
2.1
|
89.3
|
61,100
|
|
|
2.1
|
95.0
|
57,000
|
|
|
2.5
|
95.0
|
44,400
|
|
| 15 million |
1.9
|
89.3
|
139,800
|
|
|
2.1
|
89.3
|
129,400
|
|
|
2.1
|
95.0
|
124,500
|
|
|
2.5
|
95.0
|
107,000
|
|
| 1. We assume net migration of -3,000 for the year ended June 2012. |
| Source: Statistics New Zealand |
Could our population reach 10 million or more?
For our population to reach 10 million by 2061, New Zealand needs a sustained net migration gain of nearly 70,000 a year (assuming median fertility and mortality).
To reach 15 million in 2061, we require 140,000 net migration every year in 2013–61. This is equivalent to roughly 210,000 immigrants each year, assuming emigration averaged 70,000 a year. However, if net migration increases gradually over time from the assumed -3,000 in 2012, then to reach 15 million we need significantly more than 140,000 migrants a year as we near 2061.
In summary
For New Zealand to reach a population of 7 million or more by 2061, we need sustained fertility and/or migration levels that are significantly higher than those we have experienced in recent decades.
Using past growth rates or natural increase levels to project populations over a long period is too simplistic. This is because New Zealand's changing age structure makes the way our population will change in the future different from the past.
For more information on the 2011-base projections see National Population Projections: 2011(base)–2061.
Published 19 July 2012