Abstract

As part of the online panel IAB-OPAL, an experiment is conducted to increase panel consent. The experiment investigates the extent to which the timing of obtaining panel consent and the amount of monetary incentive influence participants' willingness to commit to long-term participation in a study. Respondents are randomly assigned to four groups, which differ in terms of the timing of asking for panel consent and the incremental incentivization. The experiment addresses two central research questions: First, it examines whether asking early for panel consent leads to higher consent rates than asking later on in the survey. Second, it analyzes whether an increase in incentives actually results in higher panel consent. Besides immediate consent for panel participation, the long-term effect of the intervention is also investigated. We evaluate whether the experimental groups differ in their actual registration on the study portal and their willingness to participate in follow-up surveys. The findings will contribute to optimizing strategies for panel recruitment in online surveys and provide insights into the effectiveness of different recruitment approaches.