Purpose of agency
Statistics NZ, New Zealand’s national statistical office and leader of the Official Statistics System, has been delivering New Zealand's most important official statistics for 120 years. It is governed by and administers the Statistics Act 1975. Under Section 3 of the Act, Statistics NZ holds a census every five years.
What high value public data has been released for re-use?
The census is one of New Zealand’s most important data sources and much of the census data is released for re-use. Statistics NZ released aggregated, confidentialised data from the 2006 Census including information on age, ethnicity, income, workplace, dwelling size and other variables.
Data included summary statistics, aggregate data in the NZ.Stat tool available via the Statistics NZ website (previously Infoshare and Tablebuilder), and a meshblock dataset. Data is available in comma delimited (.csv), Excel (.xls), Access (.mdb), Table Query (.tqx) and Beyond 20/20 (.ivt) formats.
The 2006 Census meshblock dataset contains counts at the meshblock level for selected variables from the 2006, 2001 and 1996 Census of Population and Dwellings, rebased to 2006 Census boundaries. This dataset also contains counts for area units, wards, territorial authorities, and regional council areas. The meshblock dataset can be integrated with other databases or mapping systems to assist analysis and decision making. Examples of re-use can be found at www.data.govt.nz/dataset/show/2286.
Releasing data for re-use is part of the census programme. Under the Statistics Act, release of official statistics must be balanced with the protection of personal information. A dedicated project team develops products and data for release, including output systems, tools, and supporting metadata. For each new census, changes and improvements to this range of products are made, based on user feedback.
Confidentiality and privacy - Information Statistics NZ collects can only be used for statistical purposes, must be kept secure to prevent unauthorised access, and must not be released where it could lead to disclosure of individuals' details. Where necessary, Statistics NZ adjusts data to make sure that no individual or business can be identified, using techniques such as random rounding, collapsing categories, and suppressing cells. Under specific conditions, researchers can access anonymised unit record data. See the census confidentiality rules at www.stats.govt.nz/Census/about-2006-census/methodologypapers/2006-census....
Data quality - Census data must meet the quality criteria set out in the Principles and Protocols for Producers of Tier 1 Statistics. The census aims to meet information needs with data that is fit-for-purpose. Of fundamental importance are the accuracy of the population count and statistics on the characteristics of small populations. Significant emphasis is given to ensuring the quality of core census variables including age, sex, ethnicity, and location. The 2006 Census achieved a coverage rate of 98 percent and the response rate was 94.8 percent. A post-enumeration survey measures the undercount,which was 2 percent in 2006.
Cost and timeframe
Release of data for re-use, as part of the core census budget, does not incur additional cost.
Census data is released in a phased manner following each census.
Access census data at www.stats.govt.nz/Census.aspx.
Note that the 2011 Census was deferred until March 2013 due to the 2011 Canterbury earthquakes. 2013 Census results will be released from December 2013.
Economic and social impacts
- The meshblock dataset is the basis of Mashblock, a mashup site, allowing users to view census information for geographical areas
- census data underpins the Wellington City Council community profiles
- property developers and consultants use the census count of dwellings to assess potential property sales and demand for future developments
- iwi authorities depend on census information for monitoring iwi post-treaty development plans
- prospective home buyers can access census information to assess neighbourhoods and inform their purchasing decision. Census data is mashed up with property and education information and made available in property reports on Zoodle (www.zoodle.co.nz).
Transparency and democratic impacts
- Te Puni Kōkiri and other government agencies use census data on Māori for reporting on initiatives to advance Māori development and well-being, such as WhānauOra and the Māori Language Strategy
- the Government Statistician is required by law to use the results of the latest census to determine the number of General and Māori electorates for the next general election. Statistics NZ also uses census data to support the Representation Commission make its decisions about the revision of electorate boundaries
- the Ministry of Education and Ministry of Health use census data to allocate funds to schools and district health boards
- census data on the size and composition of the eligible population plays a pivotal role in accurate forecasting of benefit expenditure
- census data is used widely to forecast future costs across government portfolios
- census data provides an important evidence base for monitoring communities and neighbourhoods where social and economic outcomes are poor or under threat, and for developing programmes to address the challenges faced by these areas.
- census data supports researchers investigating social patterns. For example, detailed census data accessed via Statistics NZ’s Microdata Access Services contributes to the NZ Deprivation Index, the Cancer Trends and Census Mortality Studies conducted by the University of Otago
- The disabilities Resource Centre Southland used census data to assess the need for a new centre in Queenstown
- NIU Development Inc used census data to gain government support to foster the Niuean language
- local authorities depend on census data to meet accountability requirements of local government legislation, which include producing regular monitoring reports on the well-being of their populations every three years.
Re-use of this case study is licensed under a Creative Commons Attribution 3.0 New Zealand License.