Digital Nudging and Cookie Rejection: An Experiment

When browsing the Internet, web users tend to accept all cookies even though this may threaten their online security. We apply a salience nudge and a framing nudge to the design of a cookie banner and test their individual and combined effectiveness in fostering rejection of unnecessary cookies in an online experiment (N = 358). The salience nudge makes the rejection button more visible, and the framing nudge phrases button labels as negations. Compared to the control with no nudges, which elicited a rejection rate of 27%, the salience nudge increased rejection rate by 7 percentage points (but p = 0.305), the framing nudge by 18pp (p = 0.009), and the combination of the two by 53pp (p < 0.0001). We also find that, when users are offered a customization option rather than the rejection button, only 3% of them select the option and reject non-necessary cookies. Finally, we explore how cookie rejection is related to the time users spend making the decision and to their personality traits. Our findings suggest that cookie rejection can indeed be fostered by an appropriate design of cookie banners and that legislation for protecting the online security of users should introduce specific design guidelines.