Plans for Access to UK Microdata from 2011 Census

1. Plans for Access to UKMicrodata from 2011 Census Emma White Office for National Statistics 24 May 2012

2. Overview • Introduction • 2011 Census progress • Proposed products • Challenges • Microdata progress to date

3. Introduction • UK Censuses held since 1851 • Usually every ten years • Samples of anonymised records (SARs) made available for the first time in 1991 • Great Britain and Northern Ireland separately • Two files: individual, household • 2001 • Five files: individual SAR, small area microdata, special licence household SAR, individual and household controlled access microdata samples

4. 2011 Census progress • Confident that target response rates will be met • 94 per cent nationally • At least 80 per cent in every local authority in England and Wales • Fewer than 10 per cent of local authorities will be below a 90 per cent response rate • 2011 Census first release planned for July 2012 • Population estimates by age and sex to local authority • Household estimates • Web-based prospectus launched 29 March 2012

5. Six proposed products

6. Access level 3Secure products

7. Access level 2Safeguarded products

8. Access level 1Public use products

9. Challenges • Consolidation of England and Wales, Scotland and Northern Ireland data • Geography • Differences in questionnaires, variables and classifications • Level of detail and/ or geography to include in each environment • Licensing and access arrangements

10. Progress to date • Statistical disclosure control: targeted record swapping • Potential for increased sample sizes • Microdata file specifications prepared and under review • Single UK database agreed across the four countries, planning underway • Microdata planned for release from Autumn 2013 • Historical microdata under consideration • 1961, 1966, 1971, 1981

11. Contact Dr Emma White Head of 2011 Census Outputs Policy and Analysis Office for National Statistics emma.white@ons.gov.uk