Embed Size (px)
Citation preview
Introduction to the Integrated Household Survey (IHS)
Richard Clarke
Caroline Jones
ONS Social Surveys
Outline
• Background of the IHS
• How do these Social Surveys work then?
• Datasets – what and when!
• What are the results from the IHS?
Outline cont’d
• Dataset variables – End User License (EUL) vs. Special License (SL)
• Analysing the data – what to watch out for
• Questions and Answers
Background to the IHS
• ONS has several separate household surveys
Different samples, fieldwork designs and processing systems
• All surveys have similar introductions
Names, ages, work history
• Aim of the IHS is to integrate surveys into one modular survey with a core set of questions and survey modules ‘bolted’ to the core
Leading to …..
• The largest social survey ever produced by ONS
Why ONS wanted to Integrate its Surveys
• Harmonisation of questions
IHS consolidates existing work to harmonise questions over existing surveys
• Inter-Censal Data
pressure to provide more accurate data between censuses
• Demand for Local Level Data
increasing demand for more information, particularly at a local level within the UK
Surveys making up the IHS in 2009/10
• Annual Population Survey (APS) 4 wave panel interview at 12 month intervals + waves 1 + 5 of
the Quarterly LFS
• Living Costs and Food Survey (LCF)
single interview. Two week diary-keeping element.
• General Lifestyle Survey (GLF) 4 wave panel interview at 12 month intervals - longitudinal
• Life Opportunities Survey (LOS) a longitudinal survey
• English Housing Survey (EHS) single interview + surveyor visit
• Opinions Survey (OPN) single interview (OPN left the IHS after Dec. 2010)
Surveys making up the IHS in 2009/10 cont’d
IHS: 2009/ 2010 Sample Size by Component Survey
Interview Type April 2009 to March 2010 Achieved
Interviews
GLF 18,000
LCF 12,000
OPN 21,000
EHS 41,000
APS +LFS 334,000
LOS 23,000
Annual Total 449,000
•The expected breakdown of the annual sample is as follows:
• Common set of core questions
• Continual sampling
• Adding up to large scale quarterly datasets.
What is The Survey Process?
Design
PrepareTest
Conduct Survey / Collect Data
Assemble andCheck Data
Disseminate Data
Development of the questions
• Most IHS questions were pre-existing ones originating on the APS/LFS
• Sponsored questions added: e.g. for smoking prevalence
• New questions undergo extensive checks – e.g. cognitive testing and field tests before going live
• Consult with stakeholders
• Program the questionnaire
What are the IHS Core Questions
• Household composition• Accommodation• Tenure• Nationality• Country of Birth• National identity• Ethnicity• Sexual identity• Religion
• Period at current address
• Health• Smoking• Government training
scheme• Work• Looking for work• Education
Find someone to ask it to….
• The Royal Mail small user Postcode Address File (PAF) is the main sampling frame
We only interview people living in private households
Students in halls of residence or boarding
schools should be included at their parents address
Communal establishments are largely excluded
• Many are chosen.. Sadly not everyone will respond
Collecting the Data
• Data collected by CAPI
(Computer Assisted Personal Interviewing)
• 65% of interviews by field interviewers
in respondents home, remainder (mainly APS) done by telephone unit
• Respondents can answer for others in the household = Proxy Interviews
• Around 40% of IHS data collected in this wayException is sexual identity which is only asked in person
An example of what the interviewer sees
An example of a showcard used by interviewers
Please choose all that apply
1. Scottish
2. English
3. Welsh
4. Northern Irish
5. British
6. Other (please describe)
2 S
Data checks are built into the Questionnaire
Later, back in Newport
• The IHS team gets monthly data files from each survey
• Files are combined to give annual dataset
• Data cleaningMake sure all variable names are the same!
Harmonise the questions
e.g. GLF and APS have extensive education sections which
are simplified into one highest qualification variable for the
IHS
Later again…..
• Cases with missing data are imputed
• Weights are calculated
• Lots of derived variables are added
• The data set is checked
• Data is sent to GSS clients and to the UK Data Archive
What Datasets are available to you
• IHS releases data quarterly with a full years dataApril 2009 to March 2010 July 2009 to June 2010 October 2009 to September 2010 etc.
• Two type of publicly available datasets
End User License (EUL)
Special License Dataset (SL)
End User License vs. Special License
Special License• More disclosive
personal data, e.g. sexual identity, relationship grid
• Smaller Geographic areasDown to local authority
level
• Users need to apply & be accepted for approved researcher status
End User License• No disclosive
information
• Large geographic areasDown to Government
Office Regions
• Available after registration on ESDS website
Local authorities, counties
Examples of Variables ….
SLCountryGOR
Geography
Sex, ageEthnicity, marital status, national identity, religion,5 nationality categories, country of birth (3 categories UK, EU, other)
Relation to other people in household, sexual identity, civil partnerships, other nationality categories(200+), country of birth (200+ countries)
Identity SL
EUL
EUL
Variables cont’d
Industry & occupation codes
Economic activity (top coded)
Employment/training status
Detailed levels of occupation/industry coding
Work
Many more variables (197 on SL file) – see User Guides on the IHS Website
www.ons.gov.uk
EUL
SL
Analysing the IHS Data
Points to bear in mind:• Data has been imputed
Missing data “filled in” using nearest neighbour approach
• WeightingWeights to equate numbers of responses to the population
total• Household Weight – for most analysis
• Non-Proxy weight – for analysing sexual identity(Will be Sexual Identity Weight on subsequent
datasets)
• Sampling ErrorsWith any sampling survey there are confidence limits on the
data• Given in appendix 2 of the IHS bulletin
Example Output 1Results for GB and constituent countries – General Health, males aged 16+, Apr 2009- Mar 2010
42.7% 41.2% 43.3% 42.7%
37.7%34.6% 35.6% 37.4%
14.0%16.8% 14.4% 14.2%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
England Wales Scotland GB
Very badBadFairGoodVery good
Source: IHS
Example Output 2Dichotomised ‘Good’ General Health, adults aged 18-64 by Economic Position, Wales Apr 2009- Mar 2010
75.7%
50.1%
82.1%88.9% 74.0%
59.8%
78.8%88.4%
25%30%35%40%45%50%55%60%65%70%75%80%85%90%95%
In employment ILO Unemployed Inactive Good health' inWales
Male Female
Source: IHS
Media coverage
The Daily Mirror
The Sun
City AM
IHS website from www.statistics.gov.uk
Summary
• The IHS is the largest ONS Social SurveyMade up from a common core on 6 other ONS surveys
• Annual Datasets updated every 3 months
• End User License File for higher level analysis• Special User License File for more in-depth
investigations
• See the IHS Website for User Guides www.ons.gov.uk
