This privacy impact assessment (PIA) assesses the implications for integrating 2023 Census data into the Integrated Data Infrastructure (IDI).
Download the document below, or read the recommendations and summary online.
Recommendations from Stats NZ's privacy team
There are no recommendations for the integration of 2023 Census data into the IDI that are different to or not covered in the Integrated Data Infrastructure: Overarching privacy impact assessment.
These risks are system wide and not specific to any dataset:
- individuals being re-identified in the data
- unfavourable public perception of data integration
- maintaining data security
- data used for non-approved purposes.
The procedures in place to mitigate the identified risks include:
- the application of the 'five safes' framework
- the removal of unique identifying information from the datasets researchers can access
- the strict confidentiality checking of the output of analysis
- the stringent application process that researchers must follow to gain access to the IDI data, including the need to:
- seek ethics approval for all projects wanting to access health data
- meet strict access protocols in order to access the IDI data
- demonstrate that the proposed research has a statistical purpose and is for the public good.
If a review determines that the benefits no longer outweigh the risks, then the integrated datasets will be archived or destroyed (as required by the laws governing the archiving of government information).
Currently, the public benefits of the proposed data integration outweigh the potential privacy concerns. Well-established processes are in place to mitigate the risks identified, and these will continue to be reviewed and updated.
Summary
Describe the work you are doing and what you intend to achieve in as much detail as possible (as if explaining to a member of the public). Where available, include links to any relevant supporting documentation, or send it through to the Privacy Team at [email protected].
The New Zealand Census of Population and Dwellings is the official count of how many people and dwellings are in Aotearoa New Zealand. It currently provides a five-yearly snapshot of our society at a point in time and helps to tell the story of its social and economic change.
On 7 March 2023 we ran a national census, attempting to collect information from every person and household in New Zealand through a secure online form, paper forms, and directly assisting to gather response. This collection period ran from February to June 2023. We then combined this response data with administrative data to build the final data files. Extraction and combination of the administrative data was undertaken between October 2023 and February 2024.
Census information is used by government agencies, local authorities, businesses, iwi, Māori organisations, community organisations, and the public for developing and implementing new policies, research, planning, and decision-making. It helps us decide how to best use public funding, especially for health, education, housing, and transport. It is information about and for all people in Aotearoa, and Stats NZ is merely the steward of this publicly owned and accessible data. Stats NZ does put out products and services to enable access.
To assist with accessibility, we will integrate the 2023 Census microdata into the Integrated Data Infrastructure (IDI) for research under Part 5 of the Data and Statistics Act 2022. The microdata provided to the IDI is a subset of the 2023 Census information. The data is at all or most geographic and classification levels. We will also supply corresponding metadata (that is, a data dictionary and user guide) to assist those accessing this data.
The data is sent to the Integrated Data Infrastructure with names and other identifying details, which are used to match each person to the IDI 'spine'. When matching is complete, the name and day of birth are stripped from the file, and they are given an anonymised unique identifier that can link them between IDI datasets.
The IDI is only accessible by approved researchers on approved projects, in controlled data labs. These researchers must send the data through an output checking system before publishing, and making their research available is a condition of use of the IDI ).
ISBN 978-1-991307-13-2
