Understanding Society: UK Household Longitudinal Study

1. Understanding Society: the UK Household Longitudinal Studywww.understandingsociety.org.uk/Professor Vernon Gayle ISER, Essex University

2. Background • Understanding Society is a longitudinal study based on a household panel design • Basic design similar to that of British Household Panel Survey, which it will replace • Target sample size of 40,000 households – largest HPS • Main fieldwork due to started in January 2009

3. Developments • ESRC secured funding for Understanding Society from Large Science Facilities fund (normally for physical science infrastructure), Spring 2006 • November 2006 – March 2007, commissioning of principal investigator team • From April 2007, PI team starts work with consultation and commission survey organisation • September 2007, NatCen selected to deliver the survey. • January 2008, ‘Innovation panel’ survey of 1500 households starts

4. Household panel study design • Start with a sample of addresses, all members of private households found will be sample members • At each wave all sample members above a threshold age eligible for interview • Other individuals who form households with sample members after wave 1 eligible for interview • A longitudinal sample of individuals representing the whole population, and interviewed within a household context • Individuals followed as they move and form new households • Following rules mean that the study remains representative of the population as it changes, subject to weighting and except for new immigrants to the UK

5. Key features of Understanding Society • Large sample size proposed • Representative sample of whole population (all ages) • Multi-purpose multi-topic design to meet a wide range of disciplinary and inter-disciplinary research needs • Ethnic minority research • Research linking social and biomedical sciences • Innovation in data collection methods

6. Managing innovation in a longitudinal study • Timetable does not permit long lead-in to develop new method and new content • Starting in an appropriately conservative manner to ensure that the study is properly established • But ensure that there is scope for significant innovation as the study develops • Understanding Society is intended as study over several decades: new research issues and new research methods are unpredictable

7. Understanding Societysample consists of: • A new equal probability main panel achieved sample of around 27,000 households. The fieldwork for this sample will commence in January 2009 • A boost ethnic minority sample, focussed on five main ethnic minority groups, comprising 4,000 households • The BHPS sample of approximately 8,400 households. BHPS sample data collection as part of the Understanding Society will start with wave 2 in October 2009 • An Innovation Panel of 1500 households to enable methodological research. The fieldwork for the Innovation Panel will commence in January 2008.

8. Role of the Innovation Panel • 1,500 household panel, taking place one year ahead of main stage • Role is to allow experimentation and methodological development • For first 2 waves used to explore mixed mode strategy and impacts on attrition / question response • Later for new data collection methods and innovative content, e.g. web, diaries, biomarkers and health measurement, etc

9. Data collection plan • 12 month intervals between interviews • Continuous fieldwork over 24 month field period, with second wave overlapping with first • Face-to-face interview at wave 1; mixed mode at wave 2, 20%+ face to face only • Individual interview not more than 30 minutes interview administered, plus self completion and consents to link data • Some data collection by self completion from children aged 10-15 from wave 1

10. Wave 1 content • Annual repeating measures • Initial conditions and life history, asked once only • Rotating and intermittent measures first introduced at wave 1 • Young persons questionnaire for sample members aged 10-15

11. Long term content plans • Annual content – carried forward from wave 1 (< 50% of content) • New annual content – event histories over past year, follow-up questions from event or change of status, age specific modules • Relatively stable characteristics measured occasionally • Other intermittent modules repeated every 2/3 years • Scope for including emerging issues

12. BHPS and Understanding Society • At wave 2 of Understanding Society (wave 19 of BHPS), the BHPS sample will become part of Understanding Society • Expected that BHPS will use new questionnaire from that point (with very limited modification to preserve some measurement continuity) • Development process recognised importance of comparability with BHPS – so likely to be significant use of BHPS questions in Understanding Society • But, likely that a high proportion of BHPS questions will not be included, or will be asked less frequently

13. Opportunities • Starting again, compared with BHPS, an opportunity to review activities and see which are worthwhile to continue, which not • Focus on new research issues • Opportunities for mixed methods: • Data linkage – administrative, organisation, spatial • Bio-markers and health indicators • Qualitative data • Other non-standard data: diaries, visual, audio • Use of different modes • E.g. web to collect data with higher frequency • Experiment with new technology as it is introduced • Overall aim: to build a robust survey structure within which can experiment and innovate while minimising risk

14. Importance of the large sample size • 40,000 households gives an opportunity to explore issues where other longitudinal surveys are too small • Small subgroups, such as teenage parents or disabled people • Analysis at regional and sub-regional levels, allowing examination of the effects of geographical variation • Large sample size allows high-resolution analysis of events in time, for example focussing on single-year age cohorts

15. Full age range • The Understanding Society sample includes full age range at any point in time – so complements age-focused studies sampling elderly people (e.g. ELSA) or young people (e.g. birth cohort studies) • Provide a unique look at behaviours and transitions in mid-life – e.g. for issues of pensions and long-term care, associated with old age, policy setting is influenced by earlier behaviour • Large sample size means that all cohorts can be analysed at a common point in time

16. Ethnic minority research • Ethnicity strand includes: • Boost sample for five key groups (Indian, Pakistani, Bangladeshi, Carribean, Black African) • Questions focused on ethnicity issues • Raises sampling and translation issues

17. Biomedical research • Understanding Society will support collection of a wide range of biomarkers and health indicators • Opportunity to assess exposure and antecedent factors of health status, understanding disease mechanisms (e.g. gene-environment interaction, gene-to-function links), household and socioeconomic effects and analysis of outcomes using direct assessments or data linkage • Challenges: • Consents • Mode of collection • Processing, storage, access issues • Different approaches in social and biomedical sciences

18. www.understandingsociety.org.uk/