1. Adding a Mode as a Final Step in the Follow-up of a Panel Survey Seminar on New Frontiers for Statistical Data Collection Geneva, Switzerland, 31 October – 2 November 2012 Birgitta Göransson, Statistics Sweden Anton Johansson, Statistics Sweden

2. About the Survey Level of Living Survey (LNU) The survey is commisioned by Stockholm University since 1968 Panel survey 10 years between each wave Statistics Sweden has been involved in data collection in all waves The most recent wave of the survey began in 2010 and was finished in 2011

3. About the Interview Face-to-face Telephone as an option Interview length approximately 60 minutes Household survey Data collection from several members of the respondent´s household Main respondent Husband/wife/partner Children between 10-18 years old Here we focus on the interview with the main respondent

4. Population and Sample Target population: Residents in Sweden, 18-74 years old Sample size: 8889 persons Sample Number of elements Panel5 555 New Sample Units: interviewed as a child in LNU 20001 485 New Sample Units: Young adults (18-28 years)1 381 New Sample Units: Immigrants468 Total8889

5. Response Rates in LNU 1968-2010 90 % 85% 82% 79% 76% 61%

6. About the Data Collection Response rate 2010 was very low compared to the response rate in year 2000 But still, to reach this response rate (61 %) we had put much effort in the data collection: For example: Follow-ups of refusals (in some cases more than two times) Using experienced interviewers in the follow-up of refusals Tracing phone numbers and new adresses of noncontacts Could anything more be done to increase the response rate?

7. Was it possible to do a third follow-up? Respondent burden – ”I’ve told you NO two times before – why can´t you understand what I’m saying?” Interviewer burden – could we really assign this task to the interviewers? We thought that the only option at this stage was to offer the nonrespondents a very short interview Therefore, the interview was shortened by Stockholm University to approximately 5 minutes

8. The Additional Mode A short interview would most certainly have a positive effect on the response rate But, couldn´t we also give the respondents the possibility to answer the questions in an optional mode? We wanted to try this approach. Therefore, in the final follow-up, we added a paper questionnaire with the same questions as in the short telephone interview

9. Refusals and Noncontacts n% Respondents533461,3 - Face-to-face 395345,4 - Telephone 138115,9 Nonrespondents337138,7 - Not able to participate 2042,3 - Noncontacts 90810,4 - Refusals 225926,0 Ineligible Units184 Sample8889 Refusals were given the option to answer the questions in a telephone interview or as a paper questionnaire Noncontacts were only given the option to answer the paper questionnaire

10. Results of the Final Follow-up 90 % 72% 85% 82% 79% 76% 61%

11. Results of the Final Follow-up About half of the additional responses were paper questionnaires Response rate before follow-up61,3 % Short telephone interviews (earlier refusals)5,2 % Paper questionnaires (earlier refusals) 4,0 % Paper questionnaires (earlier noncontacts)1,3 % Response rate after follow-up71,9 %

12. Further work is needed The main concern with the follow-up was to increase the response rate No evaluation of mode effects with a paper questionnaire No evaluation if bias changed in the final follow- up It would be interesting to study this further!

13. Response Rate in the Different Sample Groups (n=8889) Before (%)After (%)Difference Panel63,173,910,8 New sample units: interviewed as a child in LNU2000 64,273,99,7 New sample units: Young Adults 55,267,011,8 New sample units: Immigrants 47,056,29,2 Total61,371,910,6

14. Response Rate (by Gender) Response rate before follow-up Additional responses in the follow-up

15. Additional Responses (by Mode and Gender)

16. Response Rate (by Age)

17. Additional Responses (by Mode and Age)

18. Response Rate (by Education)

19. Additional Responses (by Mode and Education)

20. THANK YOU FOR YOUR ATTENTION!