In this paper, long-term effects of convincing efforts in the PPSM-Panel are analyzed. The PPSM-Panel is a probability-based, mixed-mode Access Panel. It was recruited in 2009. For the recruitment, special effort was made to convince possible respondents and to document the refusal conversion. As shown by Vehre (2011), these efforts do have a positive effect on initial cooperation. As discussed among researchers, it is important to evaluate the effort of convincing strategies not only with respect to response rates, but also to sample composition. In Panelresearch, it is also of importance to explore the long-term effects of refusal conversion e.g. with respect to later response-behavior (e.g. Burton, Laurie, Lynn 2006).
The research question of the paper is thus twofold: first of all, we are interested in possible long-term effects of initial convincing strategies and secondly, we will focus on the question, whether people that had to be convinced differ from other panel members and thus contribute to a change in sample composition. The analysis focuses on socio-demographic variables, but other survey related items (survey attitudes, satisfying) are also discussed.