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Sub-brand to go here. Want to be an Early Bird? Can encouraging respondents to contact interviewers to make appointments increase co-operation and save costs?. Matt Brown and Lisa Calderwood Centre for Longitudinal Studies. GSS Methodology Symposium – 27 th June.
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Sub-brand to go here Want to be an Early Bird? Can encouraging respondents to contact interviewers to make appointments increase co-operation and save costs? Matt Brown and Lisa Calderwood Centre for Longitudinal Studies GSS Methodology Symposium – 27th June CLS is an ESRC Resource Centre based at the Institute of Education
Context • Survey costs increasing (Stoop, 2005) • Increased focus on cost-effectiveness • Main element of survey costs is fieldwork • Experiment conducted to attempt to reduce fieldwork costs by encouraging respondents to initiate contact with interviewers to arrange appointments
Background • “Early Bird” innovation pioneered by National Longitudinal Studies – 1979 cohort • Respondents sent letter 2 weeks prior to fieldwork inviting them to call free telephone number to arrange appointment for interview. • W22 (2004): $60/$80 incentive paid if telephoned within 4 weeks of receiving letter (+ standard incentive ($40) for completing interview). • 49% took up offer • Some impact on response rates: • 80% overall • 83% amongst those offered Early Bird • Big impact on fieldwork effort: • 3 hours to complete interviewing for Early Birds • 5 hours to complete interviewing for ‘non’ Early Birds
Research questions • Can this approach be successful on longitudinal studies in the UK context? • Incentives typical in household panel surveys but usually much lower value than US. • Can sample members be motivated to be ‘early-birds’ without a financial incentive? • Incentives unusual in cohort studies in the UK • Appeal to ‘helping’ tendencies (Groves, Cialdini and Couper, 1992) • Increasingly consumer-drive, time-poor society
UKHLS • Understanding Society: UK Household Longitudinal Study (UKHLS) • 40,000 households • Experiment conducted on the ‘Innovation Panel’ – 1500 households • Develop and evaluate methodologies for longitudinal data collection • Open call for proposals to carry out experimental designs in a longitudinal context • A unique resource for methodological research.
Implementation • Two treatment groups sent letter three weeks before fieldwork • Next wave of study about to begin • “Opportunity to request an Early Bird Appointment by contacting interviewer on their mobile phone to arrange your interview at a time that suits you”. • Also sent a leaflet “Want to be an Early Bird?” which explained the offer (identical other than mention of incentive or appeal) • Given two weeks to contact interviewer to book an appointment for any date within first 4 weeks of data collection. (Interviewers all issued with mobile phones). • Control group just sent letter
Results • Take-up of offer • Impact on response rate • Impact on fieldwork efficiency
Number of interviewer visits to complete all interviewing Results – Impact on fieldwork effort
Total Number of Interviewer Visits – All issued households Results – Impact on fieldwork effort
Summary and Conclusions • Low take-up rates: • Small incentive – in absolute terms? • Small increase in incentive relative to standard incentive? • Poor marketing? Emphasis on the term ‘Early-Bird’? • Materials not read • Mode effects – Face to face vs telephone? • Panel loyalty? • Take-up rate significantly higher if incentive offered • Appeal to ‘helping tendencies’ unsuccessful? • More emphasis on how beneficial to the respondent?
Summary and Conclusions • When taken up EB leads to big reduction in interviewer visits needed to fully complete a case (as per NLSY) • Low take-up means little impact on overall fieldwork effort • Need to boost take-up rates • Higher incentive rates? • Better marketing of the EB offer?
References • Groves, R.M., Cialdini, R.B. and Couper, M.P. (1992). Understanding the decision to participate in a survey. Public Opinion Quarterly, 56, 475-495 • Stoop, I. A. L. (2005). The Hunt for the Last Respondent: Nonresponse in sample surveys. The Hague: Social and Cultural Planning Office.