Towards a high quality 2011 Census

The 2011 Census Questionnaire

Pete BentonPete Benton

Deputy Director, Census ProgrammeDeputy Director, Census Programme

Overview

• Quick look at– Development history– Questionnaire content

• How does it all come together to produce a high quality population estimate?

• What about short term migrants?

Census provides statistics on:

• Population units: – people and housing &– key demographics (age, sex, marital status,

ethnicity)

• Population structures: – households, families

• More detailed characteristics :– eg religion, labour market status, industry,

qualifications, health/disability; etc

• Key requirement to ‘Get the Count Right’

Key lessons from 2001 Census

• Need to gather information on more than just usual residents

– Include visitors

• Need more information to aid understand of coverage

– Addresses/households– People within households

Subsequent changes in society

• More people at more than one address– Weekday residences for work– Holiday / weekend homes– Children of divorced parents

• International migration– More ‘short term visitors to UK’ – resident or not?

• Plus familiar issues of students, armed

forces, prisons, hospitals, hotels, hostels• Risk of undercount, overcount, or wrong location• Need to count the right people, in the right place

– and be able to demonstrate this with confidence

Questionnaire research to date

• Formal 3 month consultation (May 2005)

• Over 2000 responses from 500 users

• Scoring of user requirements

• Initial topic proposals

• Further topic-specific consultation

• Roadshows

• Question testing– Qualitative: Cognitive testing (6 waves over 3 years), focus

groups– Quantitative: 2007 test, omnibus survey, postal tests

Summary of user requirements

• Most 2001 topics• Many new topics, including:

- income (not included)- language- second residences- sexual identity (not included)

- national identity• More than 3 pages of questions!• Difficult trade-offs to be made• Additional £22m funding for 4th page of

questions per person obtained

New topics - population

• Population units and structures– National identity– Citizenship– Visitors– Year / month of entry into UK

• Intended length of stay??

– Second residence address and purpose

• Population characteristics– Language

New topics - housing

• Housing characteristics– Number of bedrooms– Type of central heating (just ‘yes/no’ in 2001)

Removed topics (since 2001)

• Bathroom and toilet• Size of workplace• Lowest floor level

Changed questions (selected)

• Marital status – civil partnerships• Ethnicity

– Additional tick boxes– Revised grouping / wording

• Qualification – clearer categories• Banded hours worked – actual hours in 2001• Address one year ago – identification of

students• Updated ethnicity

UK comparability

• 30 common topics– 11 others in one or more countries

• Common wording in approx 40 out of 50 questions

Production of population estimates (1)

• Step 1: Create best possible initial address register• Step 2: Census field work / initial questionnaire

processing– Add new addresses– Remove non-existent addresses– Assess status of non-responding addresses– Remove of duplicate responses

• Step 3: Assess and adjust for coverage– Of addresses / households– Of people within households, and adjust– Using address register, census and CCS data

Production of population estimates (2)

• Step 4: Quality Assure– a) Using “Census” data

• Visitors, second residences, dummy forms, migration data– b) Using other sources

• Admin data, surveys, demographic data• Step 5: Investigate

– Further visitor / second residence matching– Further admin /demographic data analysis

• Step 6: Translate to MYE base– 6 mths to 12 mths residence rule– Family/permanent residence to ‘majority of time’ address– Roll forward 3 months

• Step 7: Explain– Second residence data (questionnaires and dummy forms)– ?? Short term migrant data / intention to stay

Step 8: Investigate / Prepare for the future?

• ‘Freeze’ admin datasets on 27 March 2011• Compare census and other sources• Especially immigration data?

Second residences in coverage assessment / QA

• Duplicate returns from different locations:– e.g student counted at both term-time and parents’

address, people with second residences for the working week, children of divorced parents

• General matching process to search for duplicates

– use second residences information to help

• During QA, use to explore address status– No usual residents, clearly a second residence?

Second residences in 2007 postal test

• 2.5% of respondents said they had a second residence• A further 1% of respondents said they had a second

residence outside the UK

• Of those who said they had a second residence:– 87% entered the address

• 69% of those entered the full postcode• 11% of postcodes were half completed• 20% of postcodes were left blank

• Of those that entered an address, the highest frequency of location was London (13%), followed by West Sussex (9%)

Visitor information for Quality Assurance

• Sample matched back to usual residence– check whether they were missed where they usually live

• In CCS areas, match to CCS record for household they were visiting

– check whether they were mis-classified– Apply the mis-classification rate to visitor numbers in

non-CCS areas

• Full match in some LAs if QA suggests concerns• Considered matching all

– low cost benefit– Delays– Let the CCS do its job

Visitors in the 2001 Census

• From a sample of 7 Enumeration Areas:– 9.5% of people recorded as visitors were actually

recorded as usual residents too– 1.5% were of no fixed abode and should have been

recorded as usual residents– 17% of visitors were overseas visitors– 67% of visitors were from elsewhere in the UK

• 20% of these UK visitors were missed at their usual residence

– 4.5% of visitors did not have an address recorded

• It is estimated there will be around 2.1 million visitors on Census night in 2011

Use of short term migrant data

• Users will cross check census data with other sources– 2001: used council tax lists

• 2011: likely to use information on migrants– Already challenging MYEs on this basis– Significant volumes (at present)

• Proposal: Migrants in UK for > 1 (3?) months fill in full questionnaire, with ‘intention to stay question’

– Filter out 3-6 month migrants from UR base– But use info on numbers / characteristics

• Likely to be poor quality, but plan would be to use to understand administrative sources

– Aggregate, perhaps individual matching

“Not a census question”

• Snapshot – rapidly changing• Quality

– Will they answer the census?– Even if they do, would they answer an intention to

stay question– If so, what would the quality be like?

• Would 1 month or 3 month cut off be better?

– How could we use the resulting info anyway?

Research

• Focus groups / interviews (NCSR)• Cognitive testing• IPS interviewers• Omnibus survey• Postal test

– 10,000 random national sample of households• 50% 6 month, no intention to stay, < 6mths as visitors• 50% 1 month (full question set), with intention to stay

– 10,000 random sample from Northampton• Similar 50/50 split

High level findings

• Would fill in the census, IF they realised they had to

• Would then answer an intention to stay question– With a reasonable degree of confidence– Better with a 3 month cut-off than 1 month

• Postal test– No impact nationally– Small, statistically significant impact locally

• Still analysing the data

Discussion

• Short term migrants– Better to ‘ignore the problem’

• Discussion will happen post 2011• STMs will have to make a choice

Either explicitly or implicitly

– Better to have some information than none?• Wouldn’t provide robust estimates• New paradigm in census questions

– include a ‘poor’ topic, solely to aid administrative source analysis

• A step into a brave new world or a foolish misadventure?