Interviewer Effects in Panel Surveys

This chapter focuses on two main objectives. First, it compares different strategies in order to identify interviewer effects in panel data. The advantages and disadvantages of identification strategies are neither sufficiently discussed nor empirically compared. In this regard, a novel method that relies on the panel data structure itself is proposed. Second, the chapter analyses how interviewer effects develop in panel surveys: Are they comparatively stable or do they increase or decrease over time? It illustrates the background, defines concepts, and summarises the state of research on interviewer effects (in panel surveys). The chapter describes the data and variables. The methods and results are presented, followed by a summary and discussion. Finally, the chapter makes use of rich information about interviewers and investigates the influence of characteristics beyond socio-demographics, including their opinions on a variety of topics.