Consumer preferences for sustainability labels: A comparative analysis of the green-score and other established labels

The Green-Score label aims to complement established certifications by providing a standardized and easily interpretable assessment of products’ environmental performance. This study examines (i) the relative influence of Green-Score, organic, and Protected Designation of Origin (PDO) certifications on consumers’ willingness to pay (WTP); (ii) how label effectiveness varies across food categories; and (iii) the impact of a salience nudge on consumer choices. A Discrete Choice Experiment was conducted with a nationally representative sample of 1,102 Italian consumers, using a between-subjects design to evaluate the nudge. Results show that PDO labels, leveraging strong institutional credibility and symbolic value, consistently generate the highest marginal WTP (€7.61), especially for culturally and traditionally significant products. Green-Score A+ labels, valued for their diagnosticity and cross-product comparability, achieve an average marginal WTP of €6.25, slightly above organic certification (€4.59), with variation across product categories and treatment conditions. The salience nudge enhances the perceived value of Green-Score, particularly in contexts where environmental performance is salient, and can reduce the marginal contribution of overlapping labels such as organic certification. These findings demonstrate that the effectiveness of sustainability labels depends on both the balance between credibility and diagnosticity and the product-specific context, offering actionable insights for policymakers and stakeholders seeking to design targeted and effective environmental labelling strategies in food markets.