The effect of transparency on the temporal spillover effect of default nudges

Previous studies show that the effects of (non-transparent) nudges can spill over to later similar decisions without nudges. In the current study, we aimed to determine whether such nudge temporal spillover effects are affected by making nudges transparent. The latter is recommended to (partly) mitigate ethical concerns surrounding the use of nudges. In two experiments, we nudged participants to complete a longer version of a survey. Participants were randomly assigned to either a control, a non-disclosed nudge (using a default to promote taking the longer survey) condition or a disclosed nudge (in which the use of the default nudge was explained) condition. In both Study 1 (N = 1270) and Study 2 (N = 1258) we observed a temporal spillover effect of the disclosed nudge, suggesting that transparency does not negatively affect the temporal spillover effect.