1. Using administrative data – the statistical potential - RSS, 5 Dec 2014 Research into using administrative data and surveys to produce census and population statistics Ann Blake Beyond 2011 Programme, Office for National Statistics, UK

2. The Beyond 2011 Programme Census – every 10 years for over 200 years Review a normal part of the census cycle but the need greater than ever Rapidly changing society Evolving user requirements Technological advances Improved data sources DRIVERS : Cost, efficiency, opportunity, burden CRITERIA : Cost V social and economic benefit of outputs, privacy, public acceptability, risk etc

3. Programme Purpose Identify the best way to provide small area population and socio-demographic statistics in future Provide a recommendation in 2014 England and Wales (but similar programmes in Scotland and Northern Ireland)

4. Narrowed down to two potential approaches A census once a decade -like that conducted in 2011, but primarily online A census based on administrative data and large annual surveys

5. Major statistical challenges in using admin data No population register Nobody has attempted this without a register Definitions Data quality Incomplete Out of date (especially address data) Duplicates Erroneous entries (people abroad or have died) Not all topics are available in admin data (or that we have access to) → We would still need surveys to help adjust for data error and/or definitional differences, and fill gaps.

6. 2011 NHS Patient register population counts compared with 2011 Census population estimates Patient register is … More than 13 % lower 8.5% to 13% lower 3.8% to 8.5% lower Within 3.8% 3.8% to 8.5% higher 8.5% to 13% higher More than 13 % higher

7. Tax/Benefit register population counts compared with 2011 Census population estimates Tax system is … More than 13 % lower 8.5% to 13% lower 3.8% to 8.5% lower Within 3.8% 3.8% to 8.5% higher 8.5% to 13% higher More than 13 % higher

8. Using Administrative data and surveys to produce population estimates National Health Service Patient register (PR) Tax and Benefits Customer information System (CIS) Student data population estimates

9. Admin Data based estimates compared with 2011 Census population estimates Admin data is: More than 13 % lower 8.5% to 13% lower 3.8% to 8.5% lower Within 3.8% 3.8% to 8.5% higher 8.5% to 13% higher More than 13 % higher

10. Population Pyramids using admin data SPD 5

11. Percentage difference between administrative data based estimates and Census estimates – Output Areas (average 300 people) Percentage of OAs Percentage difference from 2011 Census Estimates

12. Using Administrative data and surveys to produce population estimates National Health Service Patient register (PR) Tax and Benefits Customer information System (CIS) 1% coverage survey Student data population estimates

13. TopicAvailability NameYes Age/Date of birthYes Marital status*Partial Address (including one year ago, alternative)*Yes EthnicityPartial National identity*Partial Country of birth*Partial Residence/migrant status*Yes/Partial Passports heldPartial Intention to stay in UKNo Language*Partial Religion*Partial Availability of census topics/variables in administrative data held by central government * Possible or known definitional differences

14. Availability of census topics/variables in administrative data held by central government TopicAvailability General health (Derived Health index/condition*) No Partial? Caring responsibilities*Partial Long-term limiting illness/disability*Partial QualificationsPartial Economic activity*Partial? Hours worked*Partial OccupationNo? Industry of employerPartial? Personal Income* (historically not included in Census) Yes Place of work*Partial Mode of travel to workNo * Possible or known definitional differences

15. 2011 Census ethnicity English School Census ethnicity White British Irish Irish Traveller/ Gypsy/Romany Indian Bangladeshi Pakistani White and Asian Other Asian Chinese African White and Black African Caribbean White and Black Caribbean Other White Other Black Other Mixed Other Ethnicity Missing Total (denominator) White British95%0.50% 2%0.50% 2%5,048,672 Irish41%47%1%0.50% 1%0.50% 5%0.50%3%0.50%2%22,609 Irish Traveller/ Gypsy/Romany 35%2%54%0.50% 6%0.50% 1%2%9,150 Indian 0.50 % 89%0.50%1% 5%0.50% 1%0.50%2%169,609 Bangladeshi 0.50 % 92%1%0.50%2%0.50% 4%99,905 Pakistani 0.50 % 1%0.50%86%1%4%0.50% 1%3%4%252,189 White and Asian 11%0.50% 1%0.50%2%54%3%0.50% 3%0.50%15%3%4%82,152 Other Asian1%0.50% 12%0.50%2% 58%1%0.50% 4%17%2%84,028 Chinese2%0.50% 1%2%83%0.50% 7%2% 27,577 African1%0.50% 1%0.50%83%1% 0.50%1%7%2%1%3%190,489 White and Black African 6%0.50% 8%55%1%3% 14%2%4%38,611 Caribbean1%0.50% 3%0.50%77%3%0.50%9%3%1%4%71,256 White and Black Caribbean 12%0.50% 2%3%62%1%2%12%1%4%108,920 Other White8%0.50%1%0.50% 1%0.50% 75%0.50%6%5%3%169,626 Other Black1%0.50% 34%1%30%2%0.50%20%6%1%4%27,625 Other Mixed10%0.50% 1%0.50%1%5%3%1%2%3%2%8%5%4%47%5% 23,763 Other Ethnicity5%0.50% 2%12%0.50%2%1%0.50% 10%2%10%50%4%66,760 Missing69%0.50% 2%1%3%1%2%0.50%4%0.50%2%1%5%1%2% 3%222,193 Census and England School Census Ethnicity

16. National Statistician’s RECOMMENDATION An online census of all households and communal establishments in 2021 - with support for those who are unable to complete the census online. AND Increased use of administrative data and surveys in order to enhance the statistics from the 2021 census and improve annual statistics between censuses.  Make the best use of all available data to provide the population statistics required and  offer a springboard to the greater use of administrative data and annual surveys in the future.

17. The evidence  Statistical research - population estimates  Statistical research - population characteristics  Public acceptability  Data linkage methods  Legislation  Independent reviews – Chris Skinner and international review  Public discussions and the consultation 30+ papers published – Search “Beyond 2011”

18. Beyond 2011 Programme conclusions – phase 1 Huge potential for use of administrative data But not there yet Way forward agreed with Government Online Census in 2021 With increased use of administrative / survey data Government ambition that 2021 Census should be the last subject to evaluation of admin data based alternative in 2021

19. Next steps - three key strands 1.2021 online Census operation Research, development, implementation & operation of a 2021 online Census Maximise online response, minimise digital exclusion 2.Integrated population statistics outputs Integration of census, admin & survey data => Production of more detailed and more frequent outputs Early benefit 2015 onwards: trial outputs 3.Beyond 2021 Ongoing development of new methods using administrative data and surveys Trial outputs and annual assessment and evaluation against 2021 census outputs Dependent on data access and data quality (and methods) In 2023, proposals for the future of the census and population statistics beyond 2021

20. Location Accuracy: PR, CIS and School Census when compared to 2011 Population Census

22. Longitudinal analysis of lag update

23. Why produce trial outputs? 1.Demonstrate continual development and improvement of methods 2.Seek user feedback on the usefulness and quality 3.Begin building time-series for comparison against MYEs, and 2021 Census – building evidence for 2023 Recommendation 4.Demonstrate ‘early benefits’ 5.Need to develop ‘operationalised’ processes

24. Annual timeline JulJunOctSepDecNovJanFebAprMarMayAug Publish trial outputs Research Conference Winter Roadshows Publish evaluation Annual MYEs published

25. What will we publish? Start with SPD-based population estimates and begin to build a time-series/compare with MYEs Start with 2013 or 2014-based output, range of geographies Over time, extend to characteristics, improve detail and quality