[Seminaire CREM] Ranking effects on recipe selection: an experiment in a mobile food application - Faculté Des Sciences Economiques

Abstract:
Favoring the consumption of healthy and environmental-friendly products is both a major public health issue and one important lever to address climate change. Yet, how to achieve these objectives and whether they are compatible still remains an open question. This study leverages a field experiment on a mobile food application that provides lists of recipes from ingredients inputed by users to investigate the effect of changing the ranking of recipes on the nutritional and environmental value of selected recipes. Alongside a benchmark group where ranking is based on recipes' grades, we randomize users into an NutriScore-based ranking and an EcoScore-based ranking groups. Using a panel-data difference-in-difference setting, we find support for a positive effect of NutriRanking (resp. EcoRanking) on the nutritional (resp. environmental) value of selected recipes. Besides, we observe that NutriRanking has a higher impact than EcoRanking, and that crossover effects are also positive. However, all effect sizes are very modest and much lower than what was pre-registered. These findings suggest that low-cost "nudging" interventions may have positive effects in terms of both health and environmental impact in the field, although such improvements are likely small.