Are Default Nudges Deemed Fairer When They Are More Transparent? People's Judgments Depend on the Circumstances of the Evaluation

To avoid concerns of manipulation, nudges should be transparent to the people affected by the intervention. Whether increasing the transparency of a nudge also leads to more favorable perceptions of the nudge is however not certain, and may depend on the circumstances of the evaluation. Across three preregistered experiments (N = 1915), we study how increased transparency affects the perceived fairness of a default nudge, in joint vs. separate, and description- vs. experience-based evaluations. We find that transparency increases perceived fairness of the nudge in a joint comparison, when the relative benefits of transparency are easy to see. However, in a real choice-context, with nothing to compare against, transparency instead decreases perceived fairness. Efforts to make nudges more ethical may thus ironically make choice architects perceived as less ethical. Additionally, we find that the transparent default nudge still successfully affects behavior, that different default-settings communicate different perceived intentions of the choice architect, and that participants consistently favor opt-in defaults over opt-out defaults nudges – regardless of their level of transparency.