Using administrative data – the statistical potential - RSS, 5 Dec 2014

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• No population register • Nobody has attempted this without a register • Definitions • Data quality • Incomplete • Out of date (especially address data) • Duplicates • Erroneous entries (people abroad or have died) • Not all topics are available in admin data (or that we have access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. 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 * Possible or known definitional differences

15. 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 ofadministrative 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 • 2021 online Census operation • Research, development, implementation & operation of a 2021 online Census • Maximise online response, minimise digital exclusion • Integrated population statistics outputs • Integration of census, admin & survey data => Production of more detailed and more frequent outputs • Early benefit 2015 onwards: trial outputs • 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? • Demonstrate continual development and improvement of methods • Seek user feedback on the usefulness and quality • Begin building time-series for comparison against MYEs, and 2021 Census – building evidence for 2023 Recommendation • Demonstrate ‘early benefits’ • Need to develop ‘operationalised’ processes

24. Annual timeline Publish trial outputs Winter Roadshows Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Annual MYEs published Research Conference Publish evaluation

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