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09 July 2024

'Nudges' can be effective tool for policymakers but consent is key

A new study has found behavioural nudges can be an effective tool even when used without consent but doing so can cause feelings of resentment towards the policy.

Nudge Illustration

While academics found that people ‘nudged’ against their wishes to donate a default amount to a charity did not subsequently change their decision when the nudge was revealed, they did express significantly higher levels of regret and resentment at the deception.

Researchers say the findings could have implications for charities trying to boost donations through nudges, showing the effectiveness both of nudges and in the informed consent of those being contacted.

The findings were revealed in a new study published in Scientific Reports and co-authored by Dr Mollie Gerver and Professor Peter John (King’s College London) with Dr Sanchayan Banerjee (Vrije Universiteit Amsterdam).

Professor Peter John, of King’s College London, said: “Our study found greater resentment was felt amongst those who did not consent to being nudged, and this resentment may be tracking some type of moral wrong. If individuals have an interest and right in controlling whether they are nudged, this interest and right can be set back even if the nudge has no effect, or has an effect that one struggles to undo.

“Our findings generate insights for organisations such as charities who are seeking to increase their received donations or in medical settings where patients could be made better off with certain defaults. In particular, our experimental insights provide good reason for organisations to ask individuals if they consent to being nudged before given a default.”

Behavioural nudges are subtle signals that encourage citizens to make welfare-improving decisions, as judged by themselves and society.

The practice has been criticised for manipulating people into making a choice that does not fit their true preferences. Two solutions are typically offered: making the nudge transparent before administering the nudge by letting people know they are about to be nudged, or seeking people’s validation for the nudge after administering the nudge by asking people if they support the nudge. In both cases, people’s consent is not explicitly considered.

For the study, the academics tested a third way: asking people’s consent to be nudged.

To test this, more than 1,500 participants were told about nudges and then asked if they would like to be nudged to donate to a charity of their choice. Following this, regardless of their consent, all participants were nudged into donating £2 out of 10 to a charity of their choice.

Following the donation choice, participants were provided with a disclosure about the nudge – those who had not consented were informed that they were nudged despite not having consented, while the remaining who had consented were informed that they were nudged as per their consent. All individuals were then asked if they would like to revise their donation amount following this disclosure and choose a revised amount.

The academics found, despite the disclosure, the amount of donations between the two groups did not significantly differ. However, the non-consenting participants reported lower levels of happiness and support, and higher levels of resentment and regret about the donation.


You can read more about the study here: Nudging against consent is effective but lowers welfare.

In this story

Mollie Gerver

Lecturer in International Ethics

Peter John

Head of the School of Politics and Economics and Professor of Public Policy