From Strangers to Acquaintances? Interviewer Continuity and Socially Desirable Responses in Panel Surveys

Abstract

In many panel surveys that rely on face-to-face interviewing, interviewers are repeatedly allocated to the same respondents in each wave. Researchers and fieldwork agencies argue that interviewer continuity can contribute to the quality of the data collected, for instance, by reducing panel attrition. However, there is almost no empirical evidence focusing on the effects of growing familiarity between interviewers and respondents on responses and measurement error in repeated interviews. This paper focuses on questions containing socially (un)desirable answer options. It is argued that interviewer continuity promotes the development of trust, emotional closeness, and loyalty, as well as interview rapport between respondents and interviewers, and that this, in turn, increases the respondents' motivation to answer truthfully rather than in a socially desirable way. Drawing on data derived from 31 waves of an ongoing household panel study in Germany, the results show a consistent effect of interviewer continuity on response behavior: Respondents who are more familiar with their interviewers are less likely to choose answer options associated with socially desirable connotations. This study provides evidence for a rare advantageous panel conditioning effect on data quality in longitudinal studies and points to the importance of taking into account the familiarity between respondents and interviewers when investigating conditioning effects on measurement error in longitudinal studies.