The effectiveness of incentives on completion rates, data quality, and nonresponse bias in a probability-based internet panel survey
Stanley, M., Roycroft, J., Amaya, A., Dever, J. A., & Srivastav, A. (2020). The effectiveness of incentives on completion rates, data quality, and nonresponse bias in a probability-based internet panel survey. Field Methods, 32(2), 159-179. Article ARTN 1525822X20901802. Advance online publication. https://doi.org/10.1177/1525822x20901802
Previous research has shown that increasing the size of incentives can increase response rates for probability-based, cross-sectional surveys. However, the effects of incentives on web panels has not been extensively studied. While larger incentives for web panelists may improve response, their effect on data quality and nonresponse bias is debatable. We sought to answer the question: what is the effect of larger, postpaid incentives on (1) response, (2) data quality, and (3) nonresponse bias for individuals in a web panel? We analyzed data from the 2015 and 2016 National Internet Flu Survey, a survey that uses the GfK KnowledgePanel® as its sampling frame. We compare panel members who received a postpaid, standard 1,000-point (the equivalent of $1) incentive in 2015 to panelists who received a larger, 5,000-point (the equivalent of $5) incentive in 2016. We found that larger incentives were associated with increased interview completion rates with minimal impact on data quality or bias.