Interviewer Effects on Respondents’ Willingness to Provide Blood Samples in SHARE

Inhalt This paper deals with the influence of the interviewer on respondents willingness to provide blood samples in the German part of the Survey of Health, Aging and Retirement in Europe (SHARE). A multilevel approach highlights the importance of the interviewer: the empty model shows an intraclass correlation (ICC) of 36% meaning that 36% of the variance are at the interviewer level. Information coming from an additional interviewer survey is used to identify determinants which can explain these effects, focussing on interviewers’ experience in the job and with the measurement as well as the expectations regarding their own success at getting respondents’ consent. The results show that interviewers’ experiences as well as their expectations are important determinants of consent. The ICC can be reduced substantially to 9%.