Subnational Population Projections

1988

Local Government Amendment Act No 3 provides for the constitution of 14 regional councils. The regional council areas cover every territorial authority area in New Zealand with the exception of Chatham Islands Territory (formerly Chatham Islands County). These replaced 22 local government regions.

1989 (1 November)

Local government reorganisation creates 74 territorial authority areas. These replaced 213 local authorities.

1991

Classification of urban areas revised into a three-part classification consisting of main, secondary and minor urban areas differentiated by population size.

1992 (1 July)

The number of regions increased from 14 to 16 following boundary reorganisation in the northern South Island.

1996

Population concept for all demographic estimates, projections and indices changed from 'de facto' to 'resident'. Population estimates based on the de facto population concept (the estimated de facto population) include visitors from overseas, but made no adjustments for net census undercount or residents temporarily overseas. Population estimates based on the resident population concept (the estimated resident population) include adjustments for net census undercount and residents temporarily overseas, but exclude overseas visitors.

The reference date for projections is shifted from 31 March to 30 June.

2006

On 6 March 2006, Banks Peninsula district merged with Christchurch city

2010

On 1 November 2010, Auckland Council became a unitary authority, when Auckland regional council area and seven territorial authority areas – Rodney district, North Shore city, Waitakere city, Auckland city, Manukau city, Papakura district, and Franklin district – amalgamated.

Nature of Projections

These projections are not predictions. The projections should be used as an indication of the overall trend, rather than as exact forecasts. The projections are updated every 2–3 years to maintain their relevance and usefulness, by incorporating new information about demographic trends and developments in methods.

Demographic projections are designed to meet both short-term and long-term planning needs, but are not designed to be exact forecasts or to project specific annual variation. Demographic projections are based on assumptions about future fertility, mortality, migration, inter-ethnic mobility, living arrangement type and labour force participation patterns of the population. Although the assumptions are carefully formulated to represent future trends, they are subject to uncertainty. Therefore, the projections should be used as guidelines and an indication of the overall trend, rather than as exact forecasts.

The projections do not take into account non-demographic factors (eg war, catastrophes, major government and business decisions, changes to the ethnic classification) which may invalidate the projections. Demographic trends are monitored regularly, and when it is necessary, the projections are revised to reflect new trends and to maintain their relevance and usefulness.

Demographic projections should not be confused with economic forecasts. Changes in the number of people, families and households do not necessarily relate to the social and economic well-being of an area. The number of people, families and households may change independently of local economic factors.

Base population

These projections have as a base the estimated resident population of each area at 30 June 2013. This population was based on the census usually resident population count of each area at 5 March 2013 with adjustments for:

1. net census undercount
2. residents temporarily overseas on census night
3. births, deaths, and net migration between census night (5 March 2013) and 30 June 2013
4. reconciliation with demographic estimates at ages 0–9 years.

For more information about the base population, refer to Population Estimates.

Subnational population projections: 2013(base)–2043 Alternative projections

Three alternative projections (designated low, medium, and high) were produced for each area using different fertility, mortality, and migration assumptions to illustrate a range of possible scenarios. The terms 'low', 'medium' and 'high' do not correspond to probabilities, but merely indicate the combination of assumptions. The medium projection series uses medium fertility, medium mortality and medium net migration for each area. The medium series is consistent with median projection (50th percentile) of the National Population Projections: 2014(base)–2068 released November 2014.

The low and high projections allow users to assess the impact on population size and structure resulting from lower growth and higher growth scenarios, respectively. The low projection uses low fertility, high mortality, and low net migration for each area. The high projection uses high fertility, low mortality, and high net migration for each area. The low and high projections are independent of the national population projections as they represent plausible alternative scenarios for each area.

At the time of release, Statistics NZ considers the medium projection suitable for assessing future population changes. However, users can make their own judgement as to which projections are most suitable for their purposes.

Statistics New Zealand, Ministry of Health, Government Planners/Local Body Planners, Ministry of Education, Consultants, Private Businesses.

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