Adapting, refining and expanding a validated questionnaire to measure food waste in U.S. households

The Household Food Waste Questionnaire (van Herpen et al. 2019a) was developed and validated as an effective instrument to identify statistically significant differences between households and to distinguish trends in household food waste over time. The original instrument was validated using consumers sampled from several European countries. We conduct a pilot study with U.S. consumers using the revised questionnaire. We find that a sample of 150 online panelists provided sufficient statistical power to replicate standard findings from the literature that smaller households and older respondents generate less food waste, but not enough statistical power to identify a statistically significant week-to-week reduction in reported food waste among households who received a food waste message rather than a control message. Power analysis conducted via bootstrapping with the pilot data suggests a usable sample size of 180 per group is required. In our study, we adapted the questionnaire for use with consumers in the United States by: • Adjusting food category descriptions and converting food quantity benchmarks to units and amounts more familiar to U.S. consumers. • Refining several elements to the questionnaire, including the addition of a visual guide to help respondents better estimate food quantities. • Expanding the approach by adding a second follow up questionnaire that permits assessment of within household changes over consecutive weeks.