Anja Weber

• Consumers often struggle to assess food's environmental impact. A product ranking based on a standardized scoring approach (aggregating multiple indicators) that is easily accessible, for instance, via a mobile app, could serve as a simple decision aid for consumers. However, to avoid information overload, research is needed in which format such information should be presented. This paper examines how different information levels of an eco-score ranking influence decision uncertainty and sustainable food choice. In an online experiment (n = 332, representative by age and gender), we compared a basic eco-ranking and an extended eco-ranking (eco-rank plus additional indicators: transportation distance and eco-certifications) against a control group (no eco-ranking) in three different food categories: milk, juice, and eggs. The basic eco-ranking successfully lowered decision uncertainty compared to the two other groups. In contrast, the extended eco-ranking did not reduce consumers' decision uncertainty level. Further, the basic (extended) eco-ranking increased the likelihood of choosing a sustainable product by 26 (17) percentage points compared to the control group. Thus, providing access to a simple eco-ranking can help avoid information overload and increase sustainable consumption.