A problem unstuck? Evaluating the effectiveness of sticker prompts for encouraging household food waste recycling behaviour

This Randomised Control Trial (RCT) investigated the effectiveness of using stickers as a visual prompt to encourage the separate collection of household food waste for recycling in two local authorities in South East England. During a baseline period of up to 15 weeks, separately collected food waste was weighed (in tonnes) and averaged across households in both treatment (N = 33,716 households within 29 defined areas) and control groups (N = 30,568 households within 26 areas). A sticker prompt was then affixed to the lids of refuse bins in the treatment group area only. Weights for both groups were subsequently measured across a 16-week experimental period. Results showed that, in the control group, there was no change in the average weight of food waste captured for recycling between the baseline and experimental period. However, there was a significant increase (20.74%) in the treatment group, and this change in behaviour persisted in the longer term. Sticker prompts therefore appear to have a significant and sustained impact on food waste recycling rates, while being simple, practically feasible and inexpensive (£0.35 per household) for local authorities to implement at scale.