Plans for Access to UK Microdata from 2011 Census Emma White Office for National Statistics 24 May 2012

Overview Introduction 2011 Census progress Proposed products Challenges Microdata progress to date

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

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

Six proposed products File 1. Secure: Individual Controlled Access Microdata Sample (CAMS) 2. Secure: Household CAMS 3. Safeguarded: Individual Samples of Anonymised Records (SAR) 4. Safeguarded: Household SAR 5. Public Use: Individual SAR 6. Public Use: Individual Test Dataset

Access level 3 Secure products FileSample sizeGeographyLicenceAvailability Individual Controlled Access Microdata Sample (CAMS) 3%Local authority/ Northern Ireland constituencies Approved researcher Office for National Statistics (ONS) Virtual Microdata Laboratory (VML) Household CAMS 3%As above

Access level 2 Safeguarded products FileSample sizeGeographyLicenceAvailability Individual Sample of Anonymised Records (SAR) 5%Local authority End user licence Special user agreement/ Download Household SAR 1%Regional or national As above

Access level 1 Public use products FileSample sizeGeographyLicenceAvailability Public Use Individual Sample of Anonymised Records 3%Regional or national Open Government Licence Download Public Use Individual Test Dataset As above

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

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

Dr Emma White Head of 2011 Census Outputs Policy and Analysis Office for National Statistics Contact