Continuity Trumps? The Impact of Interviewer Change on Item Nonresponse

Allocating the same interviewer to each respondent over multiple waves is typically recommended for panel surveys. While some studies have investigated the effect of this strategy on unit nonresponse, there is scarce empirical evidence on how interviewer (dis-)continuity affects item nonresponse. This is surprising, given that the amount and pattern of item nonresponse is a crucial aspect of data quality. Using the first seven waves of the German Family Panel pairfam, we investigate whether interviewer continuity indeed influences item nonresponse. Our analysis differentiates between "I don't know" responses and the complete refusal to answer, both with respect to the specific question of household income as well as the entire question program. By applying respondent fixed effects methods we can base our results on a within-person comparison, controlling for time-constant unobserved characteristics. Our analysis shows no detrimental effect of interviewer change over the panel; in fact, being assigned to a new interviewer even leads to lower refusal percentages. Only temporary dropouts showed lower percentages of "I don't know" answers if an interviewer change occurred. Changes in social distance with respect to age and gender do not prove to be relevant mechanisms for this effect. However, both female and male respondents exhibit a higher likelihood of "I don't know" responses over all questions when reassigned to a female interviewer. Reassignment to a more experienced interviewer produces less "I don't know" answers