How the Diagnosticity of AI-Based Sustainability Information Relates to Sustainable Consumption Behavior: The Roles of Perceived Consumer Effectiveness and Environmental Self-Identity

Artificial intelligence (AI) is increasingly used to provide sustainability-related information to consumers. Yet, its relevance to sustainable consumption may depend less on the presence of AI itself than on whether the information it provides is perceived as useful for decision-making. This study examines how the perceived diagnosticity of AI-based sustainability information is associated with sustainable consumption behavior through perceived consumer effectiveness (PCE) and environmental self-identity. Drawing on the Stimulus–Organism–Response framework and the information diagnosticity perspective, the study proposes an information–agency–identity–behavior pathway in which diagnostic sustainability information is associated with stronger perceptions of the environmental consequentiality of individual choices, which are subsequently associated with environmental self-identity and sustainable consumption behavior. Survey data were collected from 313 South Korean adult consumers with recent experience using AI-based services to obtain or evaluate sustainability-related information, and the proposed relationships were examined using structural equation modeling. The results supported the hypothesized associations: perceived diagnosticity was positively associated with PCE (β = 0.582), PCE was positively associated with environmental self-identity (β = 0.638), and environmental self-identity was positively associated with sustainable consumption behavior (β = 0.597). The sequential indirect association through PCE and environmental self-identity was significant (indirect effect = 0.214, 95% CI [0.145, 0.298]), while the direct association between perceived diagnosticity and sustainable consumption behavior also remained significant (β = 0.157, p = 0.008), consistent with complementary mediation. These findings are consistent with the proposed sequence but do not establish the temporal ordering between PCE and environmental self-identity. These findings highlight the decision relevance of AI-provided sustainability information and distinguish agency-related cognition from identity-related self-concept as complementary psychological mechanisms that may jointly relate information appraisal to sustainable consumption. The findings further suggest that the sustainability relevance of AI may depend not merely on technological adoption, but on whether AI-mediated information helps consumers evaluate environmental alternatives, recognize the significance of their choices, and connect environmentally responsible consumption with their self-concept.