Bridging Human Behavior and Environmental Norms: A Cross-Disciplinary Approach to Sustainable Tourism in Vietnam

Vietnam’s tourism sector has experienced rapid expansion, yielding significant economic gains, but also escalating environmental and socio-cultural challenges. This necessitates a shift toward sustainable tourism practices. This study develops and tests an integrative model combining the Theory of Planned Behavior (TPB) and Value–Belief–Norm (VBN) theory to investigate the Sustainable Consumption Behavior (SCB) of domestic travelers in Vietnam. Grounded in the country’s collectivist culture—characterized by a strong emphasis on communal values and social harmony—the research examines how rational decision-making and normative pressures jointly drive eco-friendly travel behaviors. Data were collected from 549 Vietnamese tourists through stratified sampling across three major regions, and were analyzed through a robust multi-step methodology, including Exploratory Factor Analysis, Confirmatory Factor Analysis, and structural equation modeling (SEM), supplemented by regression analysis. The SEM results indicate that the proposed model accounts for 60.8% of the variance in SCB, underscoring its explanatory power. Within the TPB framework, Attitude, Subjective Norms, and Perceived Behavioral Control significantly predict Behavioral Intention, which, in turn, mediates their influence on SCB. In the VBN component, Environmental Awareness shapes Altruistic and Biospheric Values, fostering the New Environmental Paradigm and activating Personal Norms, which exert a direct effect on SCB. This direct influence of Personal Norms, bypassing Behavioral Intention, highlights the role of implicit moral obligations in Vietnam’s collectivist cultural context and challenges Western-centric behavioral models. Beyond these frameworks, Destination Attributes and Consumer Innovativeness emerge as critical direct predictors of SCB, with Destination Attributes showing the strongest effect. Mediation analyses confirm Behavioral Intention’s central role, while moderation tests reveal that gender and travel experience modulate TPB-based relationships, suggesting the value of targeted interventions. Theoretically, this study advances TPB–VBN integration by applying it to a collectivist setting, revealing how cultural norms amplify normative influences on sustainable behavior. Practically, it advocates for strategies such as community-driven initiatives leveraging Personal Norms, educational campaigns to enhance Perceived Behavioral Control, and sustainable destination management initiatives in locations like Da Nang and Ha Long Bay. While the cross-sectional design limits causal claims, the findings provide a foundation for future longitudinal studies and cross-cultural comparisons, particularly in other collectivist societies, potentially incorporating digital engagement and policy incentives as novel factors.