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

Research into using administrative data and surveys to produce census and population statistics

Ann BlakeBeyond 2011 Programme, Office for National Statistics, UK

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 everRapidly changing society

Evolving user requirementsTechnological advances

Improved data sources

DRIVERS : Cost, efficiency, opportunity, burden

CRITERIA : Cost V social and economic benefit of outputs, privacy, public acceptability, risk etc

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)

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

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Out of date (especially address data)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.

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

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

Using Administrative data and surveys to produce population estimates

National Health Service

Patient register (PR)

Tax and Benefits Customer information

System (CIS)

Student data

populationestimates

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

Population Pyramids using admin data

0-45-9

10-1415-1920-2425-2930-3435-3940-4445-4950-5455-5960-6465-6970-7475-7980-8485-8990+

2.5 2.0 1.5 1.0 0.5 0 0 0.5 1.0 1.5 2.0 2.5

population (millions)

Administrative data method population pyramid with Census comparison: England & Wales

Admininstrativedata methodCensus

Males FemalesAdmininstrativedata methodCensus

SPD 5

Percentage difference between administrative data based estimates and Census estimates – Output Areas (average 300 people)

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Percentage difference from 2011 Census Estimates

Using Administrative data and surveys to produce population estimates

National Health ServicePatient register (PR)

Tax and Benefits Customer information

System (CIS)1%

coveragesurvey

Student data

populationestimates

Topic Availability

Name Yes

Age/Date of birth Yes

Marital status* Partial

Address (including one year ago, alternative)* Yes

Ethnicity Partial

National identity* Partial

Country of birth* Partial

Residence/migrant status* Yes/Partial

Passports held Partial

Intention to stay in UK No

Language* Partial

Religion* Partial

Availability of census topics/variables in administrative data held by central government

* Possible or known definitional differences

Availability of census topics/variables in administrative data held by central government

Topic Availability

General health

(Derived Health index/condition*)

No

Partial?

Caring responsibilities* Partial

Long-term limiting illness/disability* Partial

Qualifications Partial

Economic activity* Partial?

Hours worked* Partial

Occupation No?

Industry of employer Partial?

Personal Income* (historically not included in Census)

Yes

Place of work* Partial

Mode of travel to work No

* Possible or known definitional differences

Census and England School Census Ethnicity

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.

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”

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

Next steps - three key strands1. 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

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

Longitudinal analysis of lag update

Same address information on 2011 PR as Census

Different address information on 2011 PR to Census

Same address information on 2011 PR as Census

Same address information on 2012 PR as Census

Different address information on 2011 PR and 2012 PR to Census

Same address information on 2011 PR as Census

Same address information on 2012 PR as Census

Same address information on 2013 PR as Census

Different address information on 2011 PR, 2012 PR and 2013 PR to Census

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

Annual timeline

JulJun OctSep DecNov Jan Feb AprMar MayAug

Publish trial outputs

Research Conference

Winter Roadshows

Publish evaluation

Annual MYEs published

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