The Food Twin Method analysing consumer carbon footprint judgments

We address this gap by introducing the Food Twin Method, which captures realistic substitution decisions by pairing higher- and lower-CF alternatives within three supermarket categories: ready-to-eat meals, dairy products, and fruits and vegetables.

In a between-subjects survey (N = 2,069), participants estimated the CF of 18 items presented either in a structured, shelf-like format grouped by category and Food Twins or in an unstructured random order. Participants generally identified which product had the higher CF, indicating reliance on broad categorical cues. However, judgments were strongly compressed: participants showed limited sensitivity to the magnitude of differences, frequently overestimated low-CF items, and flattened large real gaps between substitutes, including within-category extremes.