We often think of population as having great inertia – when the population grows 1% or 2% per year, that means most people stayed put, right? However, population growth rates are a net figure, and there can be a great deal of inflows and outflows beneath the surface. How many people stick around in an area then provides a view of people’s loyalty or stickiness to an area.

In this article we explore the topic of population loyalty, by looking at Stats NZ’s Administrative Population Census (APC) data on usual residence one and five years ago.

We will use the share of the population living at the same residence as five years ago (or one year ago, depending on the context) as a proxy for population loyalty. However, we should note that this measure doesn’t account for people who may have stayed in the same community but moved house. As a result, this measure will understate loyalty, but it will generally be consistent across areas. The exception would be areas with high loyalty and a high proportion of renting households – even if you are loyal to your area, if you are renting, you may find yourself forced to move around regularly. Students are likely to be a key group here, who may live in the same area of a period of years, but move each year.

As of 2022, 76% of the population nationally were living at the same usual residence as they were one year ago, and 42% of the population had at the same address for the last five years. So, in broad terms, around one in four people move each year – whether that be across town, across the country, or across the world. Around three in five will people generally move within a five-year period. We’re a mobile bunch! But this mobility varies considerably by age, reflecting different levels of flexibility at different life stages.

The share at population living at the same address one- and five years ago rises between the 0-4 and 5-9-year-old age group, reflecting that families more often move around before children are of school age, and are more likely to settle down as their children enter their school years (see Chart 1). The share of the population residing at the same address as five years ago rises to a peak of 47% in the 10-14- and 15-19-year-old age groups. This peak not only reflects families settling down while children are of school age, but also the fact that as parents get older, they become more likely to own their own home, and enjoy the stability that comes with home ownership.

The share of the population at the same address as five years ago falls away to 29% in the 20-24-year-old age group, and reaches a trough of 18-20% in the 25-29- and 30-34-year-old age group. This trough reflects young people leaving home and moving around – whether that be from rented flat to rented flat or exploring different parts of the country or world.

The share staying at the same address rises sharply between 30-34 and 35-39 years old, to 29%, reflecting the stage at which many people ‘settle down’ – including starting a family and buying a house. The share rises sharply again, to 40% in the 40-44 year old age group, and 49% in the 45-49 year old age group. From ages 60-69, there’s something of a lull, as people often look to reassess their living arrangements after children leave home and as they approach retirement. The share remaining in the same house peaks at 79% in the 75-79 year old age group, by which time most people are into retirement, before falling away to 59% in the 90 years and older age group, reflecting people moving to different living arrangements to suit the final years of their lives – whether that be in a retirement village, a rest home, or with family.

Before diving into specific centres, it’s useful to look at the broader trends in population loyalty. Chart 2 shows that our rural areas consistently have the greatest loyalty, with over 55% of the population in 2022 still living at the same address as five years ago. Rural settlements are similarly sticky, with 52% still living at the same address. At the other end of the spectrum are our urban areas – major urban areas (e.g. Auckland), medium urban areas (e.g. Whangārei) and small urban areas (e.g. Timaru) all have similar loyalty, with 46-48% of residents in 2022 still living at the same address as five years ago.

Strong population growth and migration over the 2010s had the effect of driving down loyalty, as it effectively increased the flows of new residents, thus diluting existing loyal residents.

Drilling down to territorial authorities in Chart 3, we see that the areas with the least loyal populations are generally those with the fastest population growth, which reflects the phenomenon of new residents effectively diluting existing loyal residents. Queenstown-Lakes reported the lowest loyalty, with only 33% of their population in 2022 still living at the same residence as five years ago. Queenstown-Lakes recorded the second fastest population growth in the five years to 2022. Tauranga reported the third lowest loyalty at 43%, and the fifth fastest population growth. Selwyn reported the fifth lowest loyalty at 45% and fastest population growth.

However, areas such as Hamilton, Christchurch, Palmerston North, and Auckland all reported low loyalty, despite moderate population growth. These areas all experience strong international net migration, with migrants often coming to these main centres first, and then moving on to regional centres after finding their feet in New Zealand, and it is this churn which affects the loyalty measure.

Kaikoura’s loyalty started to fall after the 2016 Kaikoura earthquake, reflecting an influx of workers for the area’s post-earthquake infrastructure rebuild.

Moving onto specific urban areas is more illuminating that territorial authorities, with Table 1 revealing that towns with the most loyal residents are largely small communities with a strong reputation for lifestyle and community identity. The top five settlements for loyalty were Muriwai (Auckland), Brighton (Dunedin), Paekākāriki (Kāpiti Coast), Diamond Harbour (Christchurch), and Bluff (Invercargill).

By contrast, the least loyal communities are generally growth hotspots, reflecting the same relationship between population growth and loyalty seen in Table 1 for territorial authorities. In the case of these growth hotspots, many of the houses there today would not have existed five years ago. Among the least loyal areas are Pokeno (24%), Queenstown (27%), Kumeu-Huapai (28%), Te Kauwhata (31%), Lake Hawea (32%), and Pegasus (32%).

There are exceptions to this rule however, and Kaitaia is one – only 38% of their population lived in the same residence as five years ago, but their population growth hasn’t been particularly strong. Kaitaia has a relatively low home ownership rate, with only 46% of households owning their own home, compared to 65% nationally, based on the 2018 Census. Insecure housing tenure could lead to Kaitaia’s households moving more frequently.

The least loyal area is Burnham Camp, which is almost entirely Army barracks, where only 13% of the population in 2022 resided in the same residence five years ago.

Differences in loyalty can make a big difference in how communities come together and form a collective identify. Do they know their neighbours? Do they participate in local groups? To what degree can they band together and support each other in a time of crisis? To an extent, community loyalty is evidenced by the well-known community identity common across the communities with the most loyal residents, such as Raglan, Muriwai and Paekākāriki.

However, areas with a relatively new population can still form strong connections, with a little help. Selwyn District Council have recognised the importance of community connections. To overcome the challenge of low population loyalty that comes from a fast-growing population, Selwyn District Council funds small neighbourhood gatherings to help form community connections. Now is great time for this sort of initiative, as record high migration inflows and outflows are likely to reduce the proportion of the population living at the same address as five years ago.