Using social norms to reduce plate waste in corporate dining.

Food waste is a massive global issue, resulting in unnecessary carbon emissions and unnecessary costs. Because of their scale, corporate dining settings have a major role to play in reducing food waste. To minimize the amount of waste produced by corporate dining settings, waste produced by the consumers - plate waste - cannot be ignored. In this work, we applied behavioral science methods to reduce plate waste at a large international technology company (Google). In Study 1, we conducted a global survey to understand social norms surrounding food waste. Findings from Study 1 informed the development of social norms-based messaging that emphasized that waste reduction was an almost unanimously shared value among employees. Studies 2 and 3 tested the effectiveness of social norms messaging and portion prompting signage in six cities across five countries around the world. We used cutting-edge waste tracking technology to track the actual amount of waste produced across a total of 13,150 user meals. Results from difference-in-difference RCTs showed that these interventions reduced waste by an estimated 31% compared to expected levels without signage. These findings demonstrate that behavioral science methods offer a cost-effective, scalable approach to reducing plate waste in corporate dining environments.