Public overconfidence in understanding food date labeling undermines our efforts to reduce food waste

Given the profound social, economic, and environmental consequences of food waste, identifying effective and timely strategies to mitigate this issue is imperative. While prior research has explored the connection between consumers' misunderstanding of food date labeling (FDL) and food waste, questions remain regarding both the discrepancy between consumers' subjective (self-reported) and objective (test-based) knowledge of FDL, and how subjective knowledge influences the efficacy of information interventions on a global scale. Using online survey data ( N = 7830) from China, we measured consumers' subjective and objective FDL knowledge separately and constructed a knowledge deviation index. Our analysis reveals that 57.78% of consumers exhibit "knowledge overconfidence"-overestimating their understanding of FDL, and a significant correlation between knowledge deviation and food waste. Although the randomized information intervention experiment and difference-in-differences (DID) model results demonstrate the effectiveness of specific label information in enhancing consumers' objective FDL knowledge and reducing food waste willingness, the subsequent fixed-effects model results indicate that subjective FDL knowledge significantly hinders the beneficial effects of the intervention on both knowledge correction and the reduction in willingness to waste food. These findings offer novel insights for policymakers and stakeholders working toward United Nations Sustainable Development Goal 12.3 "halve food waste by 2030" by highlighting the critical role of addressing knowledge overconfidence in reducing food waste.