Sustainability discourse in tourist reviews: Activation, framing, and associations with ratings

Sustainability is widely promoted in tourism, yet it appears unevenly in tourists' evaluations. This study conceptualizes sustainability as a conditionally activated narrative dimension and distinguishes whether sustainability appears at all (eco activation) from how prominent it becomes within a review (eco-term density). Using 138,683 English- and Vietnamese-language reviews from ten island and coastal destinations in Southeast and East Asia, we combine bilingual dictionary-based text analysis, manual and machine-learning validation, and clustered regression models. After removing rating from the text-stage models, service-failure cues are negatively associated with eco activation, whereas the positive climate association is weak under small-cluster inference. Among activated reviews (N = 22,120), crowding and certification-related textual mentions are associated with less supportive framing, while climate-framing evidence is not robust. In the rating-bearing activated sample (N = 20,517), supportive eco stance remains strongly associated with higher ratings after controlling for a non-eco valence proxy. Density and density-by-stance associations do not remain statistically reliable under small-cluster and destination-balanced robustness checks. The findings therefore support a contextual view of sustainability discourse while placing clear limits on causal, cross-language, and certification interpretations. Practically, destinations and tourism firms should treat sustainability communication as something that must be backed by observable service and environmental practices, not as a guaranteed route to higher ratings. The certification result is too sparse and language-concentrated to support claims about certification itself.