Beyond 2011 – A new paradigm for population statistics?

Pete Benton, Beyond 2011 Programme Director

Office for National Statistics, UK

Programme Purpose

• Established April 2011

• To identify the best way to provide small area population and socio-demographic statistics in future

• Provide a recommendation in 2014- with cost-benefit analysis- design for implementation

Context

• Census – every 10 years for over 200 years• The potential for change

- Rapidly changing society- Evolving user requirements- Technological advances- Improved data sources- Improved data access

• Successful 2011 Census- The only approach possible in 2011

Approach

• Review user needs• Consider possible census approaches• Evaluate using published criteria, including:

- cost

- statistical quality

- social and economic benefit

- public acceptability

- risk

• Publish findings in 2014• Final decision for Government and Parliament

Beyond 2011 : Statistical options

Aggregate analysis

100% linkage to create ‘statistical population spine’

(Intermediate) Sample linkage e.g. 1% of postcodes

Address register + Survey

Administrativedata options

Traditional Census (long form to everyone)

Rolling Census (over 5/10 year period)

Short Form (everyone), Long form (Sample)

Short Form + Annual Survey (US model)

Censusoptions

Surveyoption(s)

Beyond 2011 : Statistical options

100% linkage

Administrativedata options

Traditional Census (long form to everyone)

Censusoptions

4% survey every year

Two potential future approaches

• A census once a decade, primarily online

Provides detailed statistics once every ten yearswith updated population estimates each year

• A census using existing government data and compulsory annual surveys

Provides more statistics each year, but less detail than an online census once a decade

Administrative data and surveys

Potential data sources:

•NHS Patient Register•DWP/HMRC Customer Information System•Electoral roll (> 17 yrs)•School Census (5-15 yrs)•Higher Education Statistics Agency (Students)•Birth and Death registrations

•All sources anonymised prior to linkage

Major statistical challenges

• No population register• Data quality

Incomplete

Out of date

Duplicates / erroneous entries

• Little reliable population attribute data

Þ Coverage survey requiredÞ Attribute survey required

2011 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 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

Linked admin data compared with 2011 Census population estimates

Linked 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 linked 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

Population characteristics – potential outputs

• 4% random sample per year • Gives Coefficient of Variation of 20% for

800 people using 1 year’s data• Any geographic level• Any cell in a cross-tabulation

320 people using 2 years’ data

230 people using 3 years’ data

130 people using 5 years’ data

• Additional topics from administrative data?E.g. Household income?

Public Consultation

• 23 Sept to 13 December• Series of user and other events over next

three months• Consultation Document (and lots of

supporting material and research papers) on ONS website

• Views welcome from anyone

Key risks of a census using administrative data and surveys

• Public opinion

• Data quality / technical challenge

• Changes in administrative datasets

• Managing the transition if moving to a census using administrative data

• Harmonisation of UK outputs

Next steps

• Review consultation responses• Consider legislative implications• Consider risks and potential transition plans• Consider implications for wider statistical

system (surveys; IT systems)

… Conclusions in 2014