Panel survey recruitment with or without interviewers? Implications for nonresponse, panel consent, and total recruitment bias

Abstract

Panel surveys are increasingly experimenting with the use of self-administered modes of data collection as alternatives to more expensive interviewer-administered modes. As data collection costs continue to rise, it is plausible that future panel surveys will forego interviewer administration entirely. We examine the implications of this scenario for recruitment bias in the first wave of a panel survey of employees in Germany. Using an experimental multi-mode design and detailed administrative record data available for the full sample, we investigate the magnitude of two sources of panel recruitment bias: nonresponse and panel consent (i.e., consent to follow-up interview). Across 29 administrative estimates, we find relative measures of aggregate nonresponse bias to be comparable between face-to-face and self-administered (mail/Web) recruitment modes, on average. Furthermore, we find the magnitude of panel consent bias to be more severe in self-administered surveys, but that implementing follow-up conversion procedures with the non-consenters diminishes panel consent bias to near-negligible levels. Lastly, we find the total recruitment bias (nonresponse and panel consent) to be similar in both mode groups—a reassuring result that is facilitated by the panel consent follow-up procedures. Implications of these findings for survey practice and suggestions for future research are provided in conclusion.