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Official statistics

Screenshot of the Tier 1 statistics homepage on the Stats NZ website.


The Official Statistics System (OSS) is the whole-of-government system that underpins the production of official statistics.

Stats NZ leads the OSS and is New Zealand’s major producer of official statistics. Other government agencies contribute to the OSS by collecting and supplying data, and producing official statistics.


What has been released for re-use?

Tier 1 statistics are New Zealand’s most important statistics, and are essential to help the Government, business, and members of the public to make informed decisions and monitor the state and progress of New Zealand. Tier 1 statistics describe New Zealand’s economy, environment, population, society, culture, international relations, and civil and political rights. Tier 1 statistics are also used by a range of organisations to develop new services and products. Statistics NZ and other agencies release Tier 1 statistics on their websites, with many available via NZ.Stat.

Tier 1 statistics are of good quality and have integrity. Producers of Tier 1 statistics adhere to the Principles and protocols for producers of Tier 1 statistics. Tier 1 statistics must be presented impartially and clearly without judgement and must be managed in such a way to ensure that the statistics are free from undue influence.

In August 2012, Cabinet signed off an updated list of 162 Tier 1 statistics. Some of the statistics are well-established, with summary information and statistical data available for re-use. Other statistics on the list are yet to be developed and released.


Release rationale

Tier 1 statistics are intended for public use. Guided by the principles and protocols, producers of Tier 1 statistics balance publishing these statistics with protecting private and confidential information. Access is equal and open and enough information must be provided to allow users to decide if the quality of the information fits the intended use.

In order to serve a wide range of users, Tier 1 statistical information is delivered in a broad range of formats, including information in reports and products, through to the release of aggregate data, and restricted release of microdata in limited circumstances.


Risk mitigation

Confidentiality and privacy: The confidentiality and privacy of individuals is protected at all times, in accordance with the principles and protocols. Tier 1 data must be securely stored to protect the confidentiality, integrity and security of data. Published data is aggregated and confidentialised. Where necessary, data is adjusted to make sure that no individual or business can be identified, using techniques such as random rounding, collapsing categories, and suppressing cells. De-identified personal data may be accessed only in very restricted circumstances.

Data integrity and quality: The principles and protocols have guidelines to ensure the integrity and quality of the data used to create Tier 1 statistics. For example, access to aggregate results and analysis is restricted prior to official release.

Ongoing production of Tier 1 statistics: Tier 1 statistics are the priority for the Government’s statistical production. Agencies are working together to find ways to fund the development and production of any currently unfunded Tier 1 statistics. In consultation with the Chief Executive’s Steering Group for the OSS, the Government Statistician provides annual purchase advice to Treasury and the Minister of Finance on proposed investment in official statistics.


Cost and timeframe

Costs: Tier 1 statistics are funded from appropriations to agencies. Agencies that produce Tier 1 statistics work together to ensure that the statistics are produced efficiently and cost-effectively.

Timeframes: Each Tier 1 statistic is regularly released according to a predetermined timetable. The Tier 1 list is reviewed every five years to ensure it remains relevant. Statistics that require further research or development to reach Tier 1 standards are included in the list if they can be developed within the five-year review cycle.


Economic and social impacts

  • Zoodle uses Tier 1 census data to create property reports for prospective home buyers. Zoodle was launched in January 2009 by Terralink and Real Estate NZ and has become a significant source of property information for consumers
  • NZ Public Health Observatory uses Tier 1 health and population data to create reports for public health services, district health boards, public health researchers, industry groups, and other interested parties
  • Businesses use Tier 1 data to inform decision-making, such as identifying target populations and deciding where to locate their business
  • ASB Bank has used Tier 1 data to create the Cantometer, an indicator of economic activity, designed to provide insight into the earthquake recovery
  • Community organisations use Tier 1 statistics to target their services and understand their customers. For example, the Cancer Society uses cancer registrations data.


Transparency and democratic impacts

  • Central bank performance statistics guide the decisions of investors and inform commentary on the economy and government performance
  • Tier 1 statistics are the basis for a number of the performance indicators for the Better Public Services programme. For example, immunisation coverage will be used to assess progress on increasing immunisation rates and school leavers’ highest attainment statistics will measure progress towards the target of increases in the proportion of 18 year olds with NCEA level 2 or above
  • The latest State of the Nation Report issued by the Salvation Army referred to a number of Tier 1 statistics, including criminal offences, welfare assistance, and education
  • The McGuiness Institute used Tier 1 statistics such as the planted production forest stocks data to inform ongoing work on a National Sustainable Development Strategy.


Efficiency impacts

  • Tier 1 statistics are used to allocate funding and set benefit rates. For example, the New Zealand Superannuation entitlement computation is linked to the CPI and average weekly earnings
  • Population estimates underpin decisions on electoral boundaries and are re-used to allocate health funding
  • Workforce skills (a Tier 1 statistic in development) will assist training organisations, businesses and government agencies in the education and training fields to better understand existing workforce skills, and target funding and/or services to fill priority gaps
  • Releasing an authoritative set of industry productivity statistics provides a common measure, reducing reliance on, and the cost of producing, alternative and sometimes misleading measures of productivity
  • Human induced emissions and greenhouse gas removals are reported under the Kyoto Protocol to UN Framework Convention on Climate Change, providing information on climate change cause and effect
  • Work is underway in the justice sector to provide a multi-agency view of recidivism (a Tier 1 statistic in development) which will contribute to better understanding of the risk of reoffending
  • Government financial statistics provide details of central and local government financial performance
  • Freshwater quality and soil health are being developed as Tier 1 statistics by the Ministry for the Environment, leading to consistent and coordinated data collection across all regions.


Find out more

If you have any feedback or want more information, please email You can also contact the Stats NZ Information Centre on 0508 525 525 toll-free or +64 4 931 4600.