Interventions to reduce consumers' carbon footprint: A randomized evaluation

We use a field experiment to study whether nudging individuals with information about the carbon footprint of their transport choices leads to behavioural changes. A random sample of bank-card owners who typically use private transport (e.g. cars) receives, over a period of two months, regular feedback on the carbon footprint of their transport choices, based on the observed card transactions. Another sample randomly chosen is additionally exposed to customized notifications that praise the use of public transport or propose sustainable alternatives to the use of private transport. We compare post-treatment transport-related expenditures between the two treatment groups and a control group that typically uses private transport but is not targeted with the intervention. Apps and services offering carbon calculators and carbon footprint feedback are proliferating, yet little is known about how effective they are at inducing behavioural changes and thus ultimately at helping address the climate crisis.