A Field Experiment on Biases in Food Waste Measurement Methods
(A2023-114212)

AUTHORS

Sybilla Merian, University of Zurich; Kevin O'Sullivan, ETH Zurich; Sabrina Stöckli, University of Zurich; Claudio Beretta, University of Applied Sciences Zurich; Verena Tiefenbeck, ETH Zurich, Friedrich Alexander University; Nadina Müller, University of Applied Sciences Zurich; Elgar Fleisch, ETH Zurich, University of St.Gallen; Martin Natter, University of Zurich

ABSTRACT

Reducing consumer food waste is currently on many national agendas. Despite the urgency of the issue, there is a lack of accurate measurement methods, making it difficult to quantify consumer food waste and identify effective interventions. Accurate measurement requires a deep understanding of how measurement methods are biased. In a field experiment with 369 households, we analyzed biases associated with different measurement methods (survey, diary, kitchen caddy) and procedures. Results allow us to quantify how different measurement methods deviate from each other and how biases impair reported and measured food waste estimates. Survey-based underreporting seems difficult to avoid, even when combined with other methods. Households’ awareness of food waste can only partially explain this. The analysis further suggests that results are affected by an Experimenter Demand Effect. Based on the insights generated, we discuss ideas for the improvement of measurement methods.