From Ageing-Driven Growth Towards the Ending of Growth. Subnational Population Trends in New Zealand

Abstract

In this paper we report on population change and its demographic drivers for 143 New Zealand towns, 132 rural centres and 66 Territorial Authority Areas (TAs), for the period 1976-2013. We undertook the exercise to identify whether New Zealand’s towns and rural centres are following their international counterparts in declining from what is proposed as a ‘new’ and increasingly intractable form of population decline, where net migration loss is accompanied by natural decrease, as opposed to the ‘old’ form where natural increase is positive but fails to offset net migration loss. We also examined whether ‘age-selective migration’, as in the migration-driven loss of young people and/or gain of older people, is a major factor driving New Zealand’s subnational structural population ageing. We found that the old form of depopulation, net migration loss, was the major determinant of New Zealand’s subnational depopulation across the period 1976-2013; also that migration was highly age-selective. In the process, it accelerated the structural ageing of the majority of TAs, towns and rural centres. In 2013, 41 per cent of towns and 29 per cent of rural centres had populations with greater than 20 per cent aged 65+ years (compared with just 15 per cent for Total New Zealand); 85 per cent of towns were older with migration than they would have been in the absence of migration, as were two-thirds of rural centres and four-fifths of TAs. We also found the new, ‘dual’ form of depopulation to be present, but as yet affecting a relatively small number of towns and rural centres. However, projections at TA level indicate that the shift to natural decrease and the new form of depopulation will soon escalate, the latter becoming the major cause of depopulation by 2043 and the major cause of population change per se. Overall our analysis confirms that migration is not a panacea for growth. Just 39 per cent of towns, 33 per cent of rural centres, and 26 per cent of TAs were larger in 2013 than 1976 as the result of migration. A further 27 per cent of towns, 17 per cent of rural centres, and 36 per cent of TAs also grew across the period, but were smaller with migration than they would have been in its absence; for them, natural increase played the major role in determining growth. Moreover, we found that migration is negatively correlated with natural increase, and, relatedly, that the proportion of women aged 15-44 years heavily determines natural increase. These findings suggest that areas losing their young, reproductive age population are paying the price of the gains made by other areas. These findings have a number of policy implications, all of which point to the need for regionally-specific policies.

Appendices

Appendix 1: Definition of Geographic Spatial Units Referred to in this Paper

Mesh block: A mesh block is the smallest geographic unit for which Statistics New Zealand collects statistical data. Mesh blocks vary in size, from part of a city block to large areas of rural land. Each mesh block borders on another to cover all of New Zealand, extending out to the 200-mile economic zone (approximately 320 km). Mesh blocks are aggregated to build larger geographic areas, such as area units, territorial authorities, and regional councils. At the time of the 2013 Census, there were 46,637 mesh blocks in New Zealand.

Urban area: Urban areas are statistically defined areas without administrative or legal basis. They are hierarchically subdivided into main, secondary, and minor urban areas. Together they comprise the statistically defined ‘urban’ population of New Zealand.

Main urban areas are very large urban areas centred on a city or major urban centre, with a minimum population of 30,000. Urban areas in the main conurbations have been further divided into urban zones, with each urban zone defined as a separate urban area.

Secondary urban areas were established at the 1981 Census. They have a population between 10,000 and 29,999 people and are centred on the larger regional centres.

Minor urban areas are urbanised settlements (outside main and secondary urban areas), centred around smaller towns with a population between 1,000 and 9,999 people. This complies with the international definitions of ‘urban’ population that includes towns with over 1,000 people.

Rural area: The rural areas of New Zealand are those that are not specifically designated as ‘urban’. They include rural centres, and district territories where these are not included in main, secondary, or minor urban areas; and inlets, islands, inland waters, and oceanic waters that are outside urban areas.

The standard urban area classification as used by Statistics New Zealand has two categories of rural areas: rural centres and other rural. Rural centres are defined by population size, having a population of 300–999 in a reasonably compact area that services surrounding rural areas (district territory). They have a defined statistical boundary (an area unit) but no legal status. ‘Other rural’ is the urban area classification residual category and includes all area units not in urban areas or rural centres. This category includes inlets, islands, inland waters, and oceanic waters outside urban areas.

One rural centre⁶ growing by over 2000% at the final observation 2006–2013 was deemed an outlier, substantially biasing some results, and was removed from the analysis.

Territorial Authority Area: Territorial Authority Areas have both administrative and legal status. A territorial authority is defined under the Local Government Act 2002 as a city council or district council. There are 67 territorial authorities comprising 12 cities, 53 districts, Auckland Council and Chatham Islands territory. Representing just one territorial authority area but four ‘urban zones’, the Auckland Council was formed as part of new local government arrangements in 2010. It is the single-largest administrative area, in 2013 accounting for just on one-third of the New Zealand population (Stats NZ 2013).

Appendix 2

Source Stats NZ (2017a)

Annual net permanent and long-term international migration (number), New Zealand, 1976–2016.