Improving Water-Footprint Estimates and Promoting Sustainable Food Choices: A Comparison of Three Simple Interventions

Water scarcity is intensifying globally, and a major contributing factor is thehigh water demand of food production. Changing consumers’ dietary habits couldreduce water use to sustainable levels, but this would require citizens to be wellcalibrated to the water footprint of food products. In three online experiments (totalN = 411), we tested three types of interventions to improve people’s estimates:seeding—presenting actual water-footprint values for selected food products;rule—providing a simple rule that distinguishes high- from low-water-consuming foods;and label—displaying a relative water-footprint score for selected products. Anassessment of people’s initial water-footprint estimates (i.e., before the intervention) fora wide range of food products revealed substantial limitations in calibration, both interms of metric knowledge (e.g., range and average water footprint, which were heavilyunderestimated) and mapping knowledge (i.e., relative rankings of products). Seedingled to the most comprehensive improvements in people’s estimates, enhancing bothmetric and mapping knowledge. The rule and label interventions improved onlymapping knowledge. Importantly, all three interventions also led to an improved abilityto choose the most water-efficient food products from multiple options (assessed in asubsequent task). The improved estimation abilities thus translated into moresustainable decisions. Our findings highlight water-footprint calibration as a critical yetunderappreciated factor in promoting sustainable consumption. Further, theydemonstrate that even brief interventions—particularly seeding—can effectively improveestimation competences and support environmentally responsible behavior.