Population counts and estimates fact sheet

Introduction

Purpose

There are three main population measures produced by Statistics New Zealand:

  • census night population count
  • census usually resident population count
  • estimated resident population

It is important that users are aware which population measure has been used when comparing data from different sources.

Between Censuses

The Census of Population and Dwellings gives a snapshot of the population at a point in time, every five years. To provide population data between census dates, Statistics New Zealand estimates the population, using the most recent census data as a base.

National and subnational

The definitions given below explain the inclusions and exclusions of each population measure at both the national and subnational area levels. Examples of subnational areas include territorial authorities, regional councils and urban areas.

Census population counts

Census counts

The New Zealand Census of Population and Dwellings counts people where they are on census night. As this may not be where they usually live, respondents are also asked to provide the address of their usual residence.

Census night population count

The census night population count of New Zealand (or of a subnational area) is a count of all people present in New Zealand (or in that area) on a given census night.

Census usually resident population count

The census usually resident population count of New Zealand (or of a subnational area) is a count of all people who usually live in New Zealand (or in that area), and are present in New Zealand, on a given census night.

This count excludes visitors from overseas and excludes residents who are temporarily overseas on census night.

For a subnational area, this count excludes visitors from elsewhere in New Zealand (people who do not usually live in that area), but includes residents of that area who are temporarily elsewhere in New Zealand on census night (people who usually live in that area but are absent).

Residents are counted at the meshblock (smallest geographic area for statistical purposes) of their usual address. If insufficient information about a person's usual address is given, then the geographic information that is available is used to select (impute) a meshblock within that area.

Most of the output and analysis of census data is based on the census usually resident population count.

The census usually resident population count of New Zealand at 6 March 2001 was 3,737,280.

Population estimates

Estimated resident population

The estimated resident population of New Zealand (or of a subnational area) is an estimate of all people who usually live in New Zealand (or in that area) at a given date.

This estimate includes all residents present in New Zealand and counted by the census (census usually resident population count), residents who are temporarily overseas (who are not included in the census), and an adjustment for residents missed or counted more than once by the census (net census undercount). Visitors from overseas are excluded.

For a subnational area, this estimate excludes visitors from elsewhere in New Zealand (people who do not usually live in that area), but includes residents of that area who are temporarily elsewhere in New Zealand on census night (people who usually live in that area but are absent).

Estimated resident population after a Census

The estimated resident population at a given data after a census is calculated by including births, deaths and net migration (arrivals less departures) of residents during the period between census night and the given date.

The estimated resident population of New Zealand at 30 June 2001 was 3,880,500.

Frequency of estimates

National population estimates are produced quarterly (reference dates at 31 March, 30 June, 30 September and 31 December) and subnational population estimates are produced annually (reference date at 30 June).

Comparability of counts and estimates

Counts and estimates are different

The estimated resident population is not directly comparable with the census counts. Census counts give a snapshot of the population, and are not adjusted for net census undercount or residents who are temporarily overseas.

The Census of Population and Dwellings is a five-yearly survey providing a wealth of data for: small geographic areas; variables such as occupation and country of birth; and families, households and dwellings.

The estimated resident population is updated regularly for population changes due to births, deaths and net migration. It gives the best measure of the population that usually lives in an area, for a limited range of variables (age, sex, ethnicity), and limited geographic areas.

Summary table of population measures

Inclusions and exclusions

The following table summarises the inclusions and exclusions of each population measure for an area in New Zealand on census night.

Group Census night population count Census usually resident population count Estimated resident population (1)
Residents who are present Yes Yes Yes
Residents who are temporarily elsewhere in New Zealand No Yes Yes
Residents who are temporarily overseas No No Yes
Visitors from elsewhere in New Zealand Yes No No
Visitors from overseas Yes No No

(1) Usually includes an adjustment for net census undercount of residents. For a given date after census, the estimated resident population is updated for births, deaths and net migration (arrivals less departures) of residents during the period between census night and the given date.

More information

Statistical standard

Note that the explanations above are non-standard descriptions only. For standard definitions, please refer to the Standard for Population Terms or email: info@stats.govt.nz.