A meta-analysis on the effectiveness of food-waste reducing nudges

Food waste is a global concern and is increasingly addressed by various policies and campaigns, especially in the consumption stage. Among these efforts, a promising instrument is gentle interventions based on nudges. To investigate whether and how a nudge works, we develop a theoretical framework and conduct a meta-analysis to synthesize empirical effects of nudges on reducing consumption food waste. The meta-analysis's summary effect size of cognitively-oriented nudges is a 0.27 SD (Cohen's d) reduction in food waste, and that of behaviorallyoriented ones is a 0.54 SD reduction. The effects of nudges are robust across sampled populations (i.e., U.S. vs. non-U.S. samples) but vary across settings (i.e., public vs. private). We further map nudge interventions to the driving factors of food waste behaviors and reveal potential research gaps in the literature. Based on these findings, we discuss implications for policy making to reduce food waste.