| Abstract: |
Greenhouse gas emissions from the food system constitute about one-third of
the global total, hence mitigation in this sphere of human activity is a vital
goal for research and policy. This study empirically tests the effectiveness
of different interventions to reduce the carbon footprint of food choices made
on food-delivery apps, using an incentive-compatible online randomized
controlled trial with 4, 008 participants. The experiment utilized an
interactive web platform that mimics popular online food-delivery platforms
(such as Just Eat) and included three treatment conditions: a sign-posted meat
tax, a carbon-footprint label, and a choice-architecture intervention that
changed the order of the menu so that the lowest carbon-impact restaurants and
dishes were presented first. Results show that only the choice-architecture
nudge significantly reduced the average meal carbon footprint—by 0.3 kg/CO2e
per order (12%), driven by a 5.6 percentage point (13%) reduction in
high-carbon meal choices. Moreover, we find evidence of significant health and
well-being co-benefits. Menu repositioning resulted in the average meal order
having greater nutritional value and fewer calories, whilst significantly
increasing self-reported satisfaction with the meal choice. Simple
back-of-the-envelope calculations suggest that menu repositioning would be a
highly cost-effective policy instrument if implemented at scale, with the
return on investment expected to be in the range of £1.28 to £3.85 per metric
ton of avoided CO2 emissions, depending on implementation costs. |