Abstract

Many online surveys offer incentives to enhance response rates, betting on stronger motivation for a response once respondents' participation costs are rewarded. Commonly, respondents receive monetary incentives such as cash, money transfers, or vouchers. Additionally, online panel surveys may include a points-based incentive program allowing respondents to accumulate reward points throughout the study and redeem them anytime. In 2023, the Institute for Employment Research in Germany launched a new online panel survey of the German workforce (IAB-OPAL) using a push-to-web approach. The quarterly survey utilises a post-paid points-based incentive program, allowing respondents to earn reward points in their accounts after completing the survey. They can collect these points over time and redeem them for shopping vouchers from various providers at their convenience. We comprehensively assess respondents' redemption behaviours across survey waves using individual tracking data on inflows and outflows of reward points. We analyse recurring redemption patterns and identify distinct behavioural clusters by applying econometric and machine learning methods. Additionally, we explore other dimensions of redemption behaviour, such as the timing of point redemption across different demographic groups and specific temporal trends, including seasonal peaks. Furthermore, we investigate the demographic and socioeconomic drivers of redemption behaviours, giving special attention to the respondents who collect reward points without redeeming them. We also analyse whether respondents' redemption pattern affect their survey responses and the likelihood of temporary drop-out. Our findings shed light on the dynamics of reward point redemption in online panels and have practical implications. By identifying the redemption patterns of different demographic and socioeconomic groups, we provide valuable guidance for designing online panel surveys that may incorporate a points-based incentive program. Moreover, our results can assist survey practitioners in budget planning, decision-making, and fieldwork preparation.