National Ethnic Population Projections

PDF Data Dictionary

Series Description

Title

National Ethnic Population Projections

Alternate Title

National European Population Projections

National Māori Population Projections

National Asian Population Projections

National Pacific Population Projections

National Maori Population Projections

Rights

Stats NZ

Abstract

National Ethnic Population Projections provide projected 'European or Other (including New Zealander)', Māori, Asian, and Pacific ethnic populations of New Zealand, based on different combinations of fertility, mortality, migration, and inter-ethnic mobility assumptions.

Demographic projections provide an indication of future trends in the size and composition of the population, labour force, families and households. The projections are used for community, business and government planning and policy-making in areas such as health, education, superannuation and transport. The projections are typically updated every two to three years.

Purpose

Ethnic population projections are produced to assist local and ethnic communities, as well as central government, in planning and policy-making. The projections provide information on the changing characteristics and distribution of the population, which are used to develop social policies in areas such as health and education. For example, where different ethnic groups experience different health conditions, ethnic population projections can help identify likely future service needs.

The projections are neither predictions nor forecasts. They provide an indication of possible future changes in the size and composition of the ethnic populations. While the projection assumptions are formulated from an assessment of short-term and long-term demographic trends, there is no certainty that any of the assumptions will be realised. Each ethnic population consists of all people who identify with ethnicities within that ethnic group.

It is important to note that these ethnic populations are not mutually exclusive because people can and do identify with more than one ethnicity. People who identify with more than one ethnicity have been included in each ethnic population that they identify with.

Significant events impacting this study series

1953

First set of national Māori population projections produced. The base population was the estimated de facto population of Māori ethnicity of New Zealand at 31 March 1952.

1993

First set of national Pacific population projections produced. The base population was the census usually resident population count of Pacific ethnic group (but excluding people with Māori ethnicity) of New Zealand at 5 March 1991.

1995 (September)

New birth and death registration forms introduced carrying a revised question on ethnicity. Previously the ethnic questions asked for the degree of Māori or "Pacific Island" blood, if any. The new ethnic question instructs the respondent to "tick as many circles as needed to show which ethnic group(s)...". This resulted in a number of changes:

  • the ethnic concept is now self-identified ethnicity (previously Māori and Pacific respondents were classified by their 'degree of blood')
  • ethnic vital statistics are now available for a wider range of ethnic groups (previously information was only sought for Māori and Pacific groups)
  • ethnic data is now directly available for newborn babies and the deceased (in both cases this was previously derived from their parent's ethnicity)
  • multiple response to the ethnicity question is now possible (previously the degree of Māori or Pacific blood, but not both, could be identified)
  • non-response to the ethnicity question can now be quantified.

See also Births and Deaths Profiles.

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.

1998

First set of national Asian population projections produced. The base population was the estimated resident population of Asian ethnic group of New Zealand at 30 June 1996.

2003

First set of national European population projections produced. The base population was the estimated resident population of European ethnic group of New Zealand at 30 June 2001.

2015

The first time, Statistics NZ applied a stochastic (probabilistic) approach to producing ethnic population projections. This follows the application of a stochastic approach to the national population projections (2011-base and 2014-base) and national labour force projections (2006-base, August 2012 update).

Usage and limitations of the data

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.

The 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. These projections are based on assumptions made about future fertility, mortality, migration, and inter-ethnic mobility patterns of the population. While the assumptions are formulated from an assessment of short-term and long-term demographic trends, there is no certainty that any of the assumptions will be realised.

The projections do not take into account non-demographic factors (eg war, catastrophes, major government and business decisions) which may invalidate the projections.

Projections of ethnic populations are more uncertain than projections of the total population for several reasons:

  • Ethnic identification can change over time.
  • There are greater difficulties in establishing past trends in fertility, mortality, and migration. Different ethnicities can be reported in different collections (eg birth registration form, death registration form, census form), which makes deriving ethnic-specific fertility and mortality rates problematic. Furthermore, the measurement of ethnicity has changed over time in many collections, while it is not captured at all in some collections (eg international travel and migration data).
  • Ethnic populations are not mutually exclusive because people can and do identify with more than one ethnicity. People are not asked to prioritise their ethnic responses. Hence, Statistics NZ includes people in each of their reported ethnic groups.
  • Births to parents of different ethnicities add complexity. The parents may consider the child to belong to one or more of their ethnicities, or indeed to another ethnicity.
  • There is greater future uncertainty about the components of population change. For example, it is uncertain whether the fertility and mortality of different ethnicities will converge, and if so, at what pace. Assumptions about future migration, notably for people of Asian and Pacific ethnicities, are particularly susceptible to changes in migration patterns.

Stats NZ incorporates these factors into its methodology for ethnic population projections and has developed stochastic population projections to illustrate uncertainty. However, it is because of these factors that ethnic population projections are currently limited to the four broad ethnic groups and the 25-year projection period.

Main users of the data

Stats NZ, Ministry of Health, Government Planners/Local Body Planners, Ministry of Education, Consultants, Private Businesses

Frequency

11 Other

Information release

National ethnic population projections: 2018(base)–2043

Information release

National Ethnic Population Projections: 2013 (base) - 2038 update

Studies

Coverage

Subjects
Population, Ethnic
Keywords
European, Maori, Asian, Pacific, Māori

National Ethnic Population Projections

Name
National Ethnic Population Projections
Label
National Ethnic Population Projections

Methodology

Methodology

Methodology

A special cohort component method has been used to derive the ethnic population projections. By this method, the base population is projected forward by adding new birth cohorts and calculating the effect of deaths, migration and inter-ethnic mobility within each age-sex group according to specified mortality, migration and inter-ethnic mobility assumptions. New birth cohorts are generated by applying specified fertility assumptions to the female population of childbearing age, and specified paternity assumptions to the male population.

The method differs from the conventional cohort component method in two respects:

  • For each ethnic group, births are projected separately for women, and for men where the mother is not of that ethnic group. For example, Māori births have been projected separately for Māori women, and for Māori men where the mother is non-Māori.
  • The projections allow for population change due to inter-ethnic mobility (i.e. people changing their ethnic identification over time).

Fertility and mortality assumptions are derived for the purpose of projecting each population and should not be used as a precise measure of fertility or mortality differentials between ethnic groups.

Ethnic Concept

The ethnic concept used in these projections is the ethnic group or groups that people identify with or feel they belong to. Ethnicity is self-perceived and people can identify with more than one ethnicity. Ethnicity is different from ancestry, birthplace, and nationality. For example, people can identify with Māori ethnicity although they may not be descended from a Māori ancestor. Conversely, people may choose to not identify with Māori ethnicity even though they are descended from a Māori ancestor.

See Review of the Measurement of Ethnicity or the ethnicity classification for more information about ethnicity including information about the Statistical Standard for Ethnicity 2005.

European or Other

Projections have been derived for the combined 'European or Other (including New Zealander)' ethnic group. Sufficient demographic data is available to enable projection assumptions to be derived for the combined ethnic group, but not for the separate 'European' or 'Other (including New Zealander)' ethnic groups defined in level one of the ethnicity classification. This approach is consistent with Guidelines for Using Ethnicity Data: 2006 Census. If a person belongs to both the 'European' and 'Other' ethnic groups, they have only been counted once. Almost all people in the 'Other' ethnicity group belong to the 'New Zealander' sub-group.

Stochastic (probabilistic) population projections

Stochastic (probabilistic) population projections are produced to give estimates of uncertainty, although these estimates are themselves uncertain. The stochastic population projections are produced by combining 2,000 simulations of the assumptions. These simulations can be summarised by percentiles, which indicate the probability that the actual result is lower than the percentile. For example, the 25th percentile indicates an estimated 25 percent chance that the actual value will be lower, and a 75 percent chance that the actual result will be higher, than this percentile.

Nine alternative percentiles of probability distribution (2.5th, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 97.5th percentiles) are available for the 2020-base projections.

At the time of release, the median projection (50th percentile) indicates an estimated 50 percent chance that the actual value will be lower, and a 50 percent chance that the actual value will be higher, than this percentile.

Extra Metadata