Consumer responses to sustainability signals: how country-of-origin image and eco-labels shape Willingness to pay

Against a background where sustainability and responsible consumption are becoming central to public discourse and strategic decision-making, this thesis explores how Country-of-Origin (COO) cues and sustainability signals (specifically, eco-labels) influence consumers’ perceptions of product sustainability and, ultimately, their willingness to pay (WTP). Addressing a critical gap in international marketing and sustainable consumption literature, the thesis develops an integrative conceptual model grounded in signaling theory, cue utilization theory, and attribution theory to uncover not just whether, but how and why these extrinsic cues shape consumers’ sustainable behavior. Departing from the dominant reliance on consumers’ attitudinal responses in prior research, the thesis adopts WTP as a robust behavioral outcome measure and employs a differentiated replication design, involving four complementary experimental studies in Italy. These studies vary in terms of product category (chocolate vs. microwave ovens), COO stimuli (Bulgaria, Denmark, Türkiye, Germany), and sustainability cues (Fairtrade vs. Energy Star). Results consistently show that both country image evaluations and the presence of sustainability labels significantly enhance perceived product sustainability, which in turn increases WTP—an effect weakened by consumer skepticism. The thesis makes several theoretical contributions: it demonstrates the mediating role of perceived sustainability between COO and sustainability cues on WTP, the predominantly additive (rather than interactive) effects of COO signals and labels, and the relatively stronger influence of country image on WTP. Furthermore, it highlights how individual-level factors, such as attribution of responsibility, can strengthen the link between sustainability and WTP in specific product contexts, although other moderators commonly cited in the literature on sustainable consumption (e.g., involvement in the cause, pro-environmental identity, perceived efficacy) do not modulate this relationship. The findings offer actionable insights for brands aiming to market sustainable products. They stress the importance of leveraging both country image and credible sustainability certifications to build consumer trust, especially when 6 one of the two signals is weak or ambiguous. Strategically, the results inform pricing, communications, and sourcing decisions—showing that COO is not just a marketing cue but a critical asset in sustainability positioning. By combining theoretical grounding, methodological rigor, and practical relevance, this thesis contributes to a deeper understanding of how direct (eco-labels) and indirect (COO) sustainability cues shape consumer price perceptions in international markets, and offers a solid basis for future research and applications in sustainable marketing.