From eco-signals to green trust: How tourists evaluate sustainability credibility through online reviews

Growing sustainability claims in tourism have intensified concerns about credibility and greenwashing. This study examines how tourists interpret environmental practices by analyzing 138,683 online reviews from major Southeast and East Asian coastal and island destinations. Drawing on signaling theory and attribution theory, the study proposes that observable sustainability cues are associated with eco-authenticity inference, which is linked to green trust and, in turn, more positive review sentiment. Using natural language processing, topic modeling, regression analysis, mediation analysis, and robustness checks for sparse text-derived variables, the findings show a positive association between eco-signal richness and eco-authenticity inference, as well as a significant indirect association from eco-authenticity inference to sentiment through green trust. Eco-authenticity inference is not directly associated with more positive sentiment once green trust is included. Because the focal sustainability, authenticity, and trust expressions are infrequent and have median values of zero, the findings identify a consistent but sparse textual pattern rather than a large or pervasive psychological effect. Because the Valence Aware Dictionary and sEntiment Reasoner (VADER) is English-oriented, VADER-based sentiment models were also checked using the English-language subset; the qualitative pattern remained consistent. Topic modeling provides supplementary contextual evidence that sustainability discourse in reviews is episodic and grounded in concrete visitor experiences. Practically, the findings suggest that destinations and tourism providers should make sustainability practices visible, verifiable, and experience-based rather than relying on abstract promotional claims.