Nudging against consent is effective but lowers welfare.

Behavioural nudges are often criticised because they "work best in the dark". However, recent experimental evidence suggests that the effectiveness of nudges is not reduced when they are delivered transparently. Most people also endorse transparent nudges. Yet, transparent nudging may undermine human autonomy-a minority may oppose to being nudged and feel manipulated, even if they know what is happening. We propose an alternative way of maintaining autonomy that is not reducible to transparency: individuals can be asked if they consent in advance to being nudged. To assess whether consensual nudges are effective, we ask consent from 1518 UK citizens to be nudged. Subsequently, we default all participants into donating to a charity of their choice, irrespective of self-reported consent. We find that the default nudge is equally effective for both consenting and non-consenting individuals, with negligible difference in average donations. However, non-consenting individuals report higher levels of resentment and regret and lower levels of happiness and support compared to the consenting group. Based on these findings, we argue that ignoring consent can have serious ethical ramifications for policy-making with nudges.

Thinking about default enrollment lowers vaccination intentions and public support in G7 countries.

Policymakers often face a conundrum between being transparent about policies and ensuring that those policies are effective. This challenge is particularly relevant for behavioral nudges, which are not usually disclosed. Rather than avoiding transparency, we suggest that policymakers encourage citizens to reflect on nudges to help them understand their own views and align those views with their behaviors. Using data from an online survey experiment with 24,303 respondents in G7 countries, we examine the impact of reflection on a hypothetical default nudge policy for COVID-19 booster appointments. Contrary to expectations, participants say they would be less likely to get the booster when automatically enrolled compared with a control condition. Similarly, encouraging citizens to think about the status quo (baseline) policy also reduces intentions for boosters. These interventions have no effect on approval of the policy. Further, encouraging people to think about automatic enrollment decreases approval of the policy and further decreases their intentions to get vaccinated. These findings suggest that reflection on a nudge can increase backlash from a nudge and also elicit policy disapproval, thereby aligning policy support with behavioral intentions.

The future of experimental design: Integrative, but is the sample diverse enough?

Almaatouq et al. propose an "integrative approach" to increase the generalisability and commensurability of experiments. Yet their metascientific approach has one glaring omission (and misinterpretation of) - the role of sample diversity in generalisability. In this commentary, we challenge false notions of subsumed duality between contexts, population, and diversity, and propose modifications to their design space to accommodate sample diversity.

Public support for more stringent vaccine policies increases with vaccine effectiveness.

Under what conditions do citizens support coercive public policies? Although recent research suggests that people prefer policies that preserve freedom of choice, such as behavioural nudges, many citizens accepted stringent policy interventions like fines and mandates to promote vaccination during the COVID-19 pandemic-a pattern that may be linked to the unusually high effectiveness of COVID-19 vaccines. We conducted a large online survey experiment (N = 42,417) in the Group of Seven (G-7) countries investigating the relationship between a policy's effectiveness and public support for stringent policies. Our results indicate that public support for stringent vaccination policies increases as vaccine effectiveness increases, but at a modest scale. This relationship flattens at higher levels of vaccine effectiveness. These results suggest that intervention effectiveness can be a significant predictor of support for coercive policies but only up to some threshold of effectiveness.

Nudge or not, university teachers have mixed feelings about online teaching.

We designed and administered an online survey experiment to 444 educators in a large social sciences university in the United Kingdom to evaluate their perceptions on the effectiveness of online teaching methods. We find that a nudge, designed to inform educators about the benefits of online teaching, does not improve the personal evaluations of educators in our sample (ntreat = 142, ncontrol = 142) about this new mode of teaching. Overall, most respondents in our sample report being comfortable with online teaching methods and think this form of teaching can continue to have some positive impact. Nonetheless, they do not favour any further online transition away from traditional modes of teaching. Online teaching is largely perceived by a majority of these educators to negatively affect student well-being and their overall university experience. We call for more experimental research in higher educational settings to evaluate the role of edunudges in improving the uptake of online teaching tools.