Where did you come from, where did you go?

The release of 2023 Census data enables us to explore the movements of people within New Zealand – internal migration – to understand not just where people have moved to, but where they have come from, and their age. We already have a good grasp of how net migration influences local population growth, but understanding more about internal migration helps us to understand the drivers and patterns across the country.

Migration is made up of internal or domestic movements, and international movements. The data that we analyse in this article is based on 2023 Census responses, and where those respondents were five years ago. This approach means that people who left the country between 2018 and 2023 aren’t captured, so we only know about inbound, not outbound international migration. For this reason, our analysis here focuses on internal migration movements.

However, we should note that internal migration is affected by international migration. International migrants typically first move to metro areas like Auckland, and then some migrants will move on to other parts of the country. Our analysis captures the second part of that movement – from their first New Zealand location to the second, but not the first – from overseas to their first New Zealand location.

Before we dive into specific regions, it’s worthwhile looking at the broader patterns around internal migration. Chart 1 shows that metro areas recorded a strong net gain of 17,700 15-29-year-olds (dark blue bar) between 2018 and 2023, reflecting that once young people leave high school, they often move away for education, employment, or simply life experiences. The majority (14,800) of these young people came from provincial areas.

However, provincial areas make substantial gains in other age groups – gaining 43,400 30-64-year-olds and 9,700 people aged 65-years-and-older. These patterns reflect that although young people may seek to leave provincial and rural areas, they are more likely to return when they are a bit older.

Diving deeper, we can look at how those general patterns play out for each specific region. Chart 2 shows that most regions record negative internal migration for 15–29-year-olds (dark blue bar), with the exception of Wellington, Canterbury, and Otago.

These flows aren’t necessarily permanent, however, with Wellington’s gain of 4,800 in the 15-29-year-old age group unwound by a net 7,900 loss in the 30-64-year-old age group. This trend implies that Wellington over the five years to 2023 gained a number of young people – likely for study – but then loses a number of people post-study or after their first post-study job. By contrast, Canterbury and Otago record a net gain across all four broad age groups, suggesting these areas are able to gain and retain people across age groups.

For Waikato, Bay of Plenty, Taranaki, Manawatu-Whanganui, West Coast, Marlborough, and Nelson-Tasman, significant net gains of 30-64-year-olds make up for the loss of 15-29-year-olds.

For Gisborne and Southland, their net loss of 15-29-year-olds is so significant that it drags their overall internal net migration negative – which means they rely on natural increase and international net migration to grow their populations. In net terms, young people that leave Gisborne and Southland don’t come back later in life.

That leaves Auckland. New Zealand’s largest city has seen a net outflow of essentially all ages groups over the 2018-23 period, with a large fall in 30-64 year olds. This outcome highlights the more usual shift to the regions that occurs after living in Auckland for some time. That’s likely true both for international migrant arrivals from overseas who settle in Auckland then shift after some time, and Kiwis who shift to Auckland for work at a younger age then over time shift to other parts of the country.

Through Census data we can look at not only where migrants are, but where they have come from. This source of migration is important because it indicates how much one area relies on another for its growth.

Focusing on Selwyn District, the fastest growing territorial authority of the past five years, Chart 3 shows that 48% of inbound migrants came from a single origin – in this case Christchurch City. Selwyn’s growth is highly sensitive to the attractiveness and economic performance of Christchurch City. If Christchurch’s growth were to stall, it would likely have a knock-on effect for Selwyn.

Kaipara has a similar story, with 55% of their inbound migrants coming from a single area – Auckland. For Auckland, 52% of migration comes from overseas, which means their overall population growth is highly sensitive to New Zealand’s international net migration. This fact helps explain why Auckland’s population fell in 2021 and 2022 while New Zealand’s borders were closed.

Focusing on our main centres, overseas is generally the largest single origin of migrants, but at the same time they have a good diversity of origins. For Invercargill, Dunedin, Christchurch, Wellington, Palmerston North, and Hamilton, overseas migrants are the largest single group yet account for less than a quarter of inbound migration.

The map also shows that more rural and provincial areas, that aren’t high-growth areas, tend to have a more diverse spread of where their internal migration comes from.

The age of incoming migrants varies widely throughout the country, reflecting that different areas attract people at different life stages. Chart 4 shows that areas with a strong reputation for pre-retirement and retirement life stages attract older migrants, such as Kaipara (average age of 44), Thames-Coromandel (52), Buller (47), and Kaikoura (47). Areas with a strong tertiary offering attract younger migrants, such as Dunedin (23) and Wellington (26). Hamilton has a strong tertiary offering too, but attracts slightly older migrants, with an average age of 29, reflecting that the city is also popular for those looking to raise a family.

Areas surrounding main centres that are more popular for raising a family tend to attract in people of child-bearing age. The average age of people leaving Wellington is 34, close to the average age of people arriving into Porirua (33), Lower Hutt (32), and Upper Hutt (34).

Understanding the makeup of your population, and the people coming to join it, is important for understanding what drives your growth, what trends your growth is most sensitive to, and can help inform campaigns to attract migrants.

Each area has a unique mix of internal migration outcomes, although as our analysis shows, there are some common themes. For a more detailed analysis of internal migration in your area, please contact Nick Brunsdon. Infometrics is able to prepare a short note on internal migration trends in your local area, with figures on who’s moving in and from where, who’s moving out and where to, and what may be driving those trends.