Communicating eco-tax labels and sustainability messages on menus: Evidence from online experiments in Austria and Germany

Reducing meat consumption is an important lever for climate mitigation, yet evidence on how menu-based sustainability cues influence food choices remains mixed. This paper reports two online experiments conducted in Austria (n = 159) and Germany (n = 399) using hypothetical menu choices in a 2 × 2 between-subjects design. The studies examined eco-tax labels as disclosure cues without actual price changes and sustainability messages, both separately and in combination. Dish-level meat choices were analysed using logistic regression models with cluster-robust standard errors at the participant level, supplemented by pooled country models and participant-level robustness checks. Sustainability messages were associated with lower odds of choosing meat in both country-specific main models, whereas eco-tax labels showed no consistent independent effect. The combined presentation of both cues produced different patterns across countries. In Austria, the eco-tax label attenuated the effect of the sustainability message, whereas the corresponding interaction was not statistically significant in Germany. A pooled model confirmed that the interaction pattern differed significantly between countries. Taken together, the findings suggest that sustainability messages may influence hypothetical online menu choices more consistently than eco-tax labels without price changes. However, given the hypothetical setting and the absence of manipulation checks, conclusions about psychological mechanisms and real-world restaurant behaviour should be drawn cautiously. The study highlights the importance of communication design and contextual sensitivity when developing and testing menu-based cues aimed at supporting more sustainable food choices.