1. Release of Microdata
John Cornish

2. Global trends
Users around the world are seeking access to more detailed data for research & analysis
More international comparisons and exchange of information amongst researchers
More NSOs are finding ways of providing access to detailed data, including microdata services
Trend towards ‘self help’ for most users
2003 Conference of European Statisticians agreed that more needed to be done to support research and analysis
But must not go beyond what is legal or acceptable to the public

3. International Guidelines
Guidelines on “Managing Statistical Confidentiality and Microdata Access” by Trewin et al
Contains many case studies on good practices
Available on the UNSD website

4. Guideline Principles
Appropriate to use microdata for research as long as confidentiality is protected
Only use for statistical purposes
Must be legal
Transparency

5. Options for microdata access
Release of confidentialised microdata files
Remote access to more detailed files
Microdata services
Data Laboratories
Research collaborations
In addition to Special tabulations & Data cubes

6. Key concerns of NSOs
Breaches of confidentiality may impact on reputation of NSO and public/respondent confidence
Response rates
Data quality may not stand up to scrutiny
Legislative authority may not be clear
Costs (documentation & confidentiality checking)

7. Key concerns of researchers
NSOs are being unduly conservative
Researchers can be trusted and have their own ethics
There is too much bureaucracy involved with access
Researchers are forced to conduct their own lesser quality surveys

8. How to manage the tension
Risk management rather than risk aversion
More clearly explain concerns of bureaucracy
Shift some responsibility to researchers
They should feel some pain for breaches

9. Australian arrangements
Specified in legislation since 1983
Used widely - ~300 releases in last 12 months
Confidentiality maintained through a mix of file modifications & access methods
Microdata Review Panel makes independent assessment of confidentiality risk for the Statistician
Users must sign legally enforceable undertaking
Criticism comes from researchers (about limitations), not the public

10. Managing the Risks Microdata Review Panel Variety of access methods
Legally enforceable undertaking is important
Withdrawal of service is easiest to implement
Training of researchers before allowing access
Audits of actual practices

11. International Microdata Services
International Census Microdata Service (IPUMS) provided by Uni of Minnesota
Key benefits to NSOs
Harmonisation of variables to facilitate comparisons across countries & time
Allows access to international data sets
Archiving & data recovery services
Documentation of microdata in English