Queenstown-Lakes district is a drawcard for people in their twenties and thirties to live in, while Thames-Coromandel has a bigger share of people nearing retirement, according to figures by Stats NZ.
At June 30 2018, the estimated resident population suggests that more than one in five people who live in Queenstown-Lakes district are aged 25 to 34 years.
This compared with nearly one in three people in Thames-Coromandel district who are aged 65 and over, with a much smaller proportion of residents in other age groups.
According to data people aged 15-39 years make up 34 percent of New Zealanders, with larger proportions living in cities like Wellington, Hamilton, Auckland, Dunedin, Palmerston North, and Christchurch (proportions range from 44 percent to 37 percent). This results in smaller proportions of residents in other age groups.
"Net migration, measured by arrivals minus departures, is driving the young age structure," says population insights senior manager Brooke Theyers. "Large urban areas attract young migrants from other areas of New Zealand and from overseas, who are seeking work or tertiary education opportunities."
The Queenstown-Lakes district, a popular tourist destination, is also attracting young adult migrants.
A larger proportion of people in younger age groups lowers the median age of a population (half are younger, and half older, than this age). The median age of residents in these areas ranges from 31.8 to 36.6 years, which is below the national average of 36.9 years.
In older age groups over 65-year-olds make up 15 percent of all New Zealanders, with larger proportions living in areas like Thames-Coromandel district, Kapiti Coast district, and Central Otago district (proportions range from 31 percent to 23 percent). The median age ranges from 47.3 to 53 years in these areas.
"Places with large proportions of people over 65 are typically those that are desirable locations for New Zealanders to retire," says Brooke. "We expect to see more age structures like these as the number of people in older age groups grows."
On the other hand under 15-year-olds make up 19 percent of New Zealanders. Kawerau and Wairoa (both 24 percent) are examples of areas that have larger proportions of children than other territorial authority areas.
These parts of New Zealand have had a relatively high number of births. Kawerau had 0.7 percent and Wairoa had 0.5 percent of growth by natural increase (more births than deaths) in the June 2018 year, which contributes to the size of the younger age groups.
These areas also do not experience the high net migration gains seen in cities and other areas. For example, Wairoa has negative net migration (more departures than arrivals) but the population remained largely stable in the June year.
Many people who leave Kawerau and Wairoa are young to middle-aged adults, as they represent the smallest proportion of Wairoa’s total population. This results in a larger proportion of residents in the other age groups.