Morality meets menu: investigating the impact of moral appeals on vegetarianism through a conjoint survey experiment

Can moral appeals motivate individuals to choose less carbon-intensive diets? In a survey-embedded forced-choice conjoint experiment involving 1520 US respondents, we asked participants to compare two menus across six dimensions: (1) burger/sandwich patty type and its corresponding carbon footprint value, (2) calories, (3) protein, (4) price, (5) ingredient origin, and (6) farming method. Within each menu, the values for these dimensions varied randomly. Further, respondents were randomly assigned to three frames: a reference frame that highlighted the scientific rationale for pro-climate action, and treatment frames with a moral-secular and a moral-religious framing of pro-climate action. We found that moral appeals did not influence individuals to make low-carbon food choices. Across the entire sample, respondents tended to favor non-vegetarian options with higher carbon footprints. Those who prioritized taste were less inclined to choose the vegetarian menu. However, some subgroups did show a preference for the vegetarian menu, including women, those with pro-climate attitudes and prior exposure to a vegetarian diet, and those who considered the health impact of their food choices. In conclusion, it appears that moral appeals are unlikely to drive significant changes in individual food choices toward a more climate-friendly food system. Instead, dietary preferences are primarily shaped by individuals’ pre-existing climate attitudes and demographics.