Psychological Drivers of Carbon Offset Choice and Spending in Air Travel: Extension of the Value–Belief–Norm Framework

This study investigates the psychological mechanisms underlying tourists’ carbon offset behavior in air travel by distinguishing between offset choice (OC) and offset spending (OS). Grounded in the Value–Belief–Norm (VBN) framework, the model integrates Environmental Value and Literacy (EVL), Green Identity and Social Motives (GISM), Trust and Risk Perception (TRP), Personal Norm Activation (PNA), and Perceived Effectiveness (PEF). Data were collected onsite from 500 international and domestic tourists at Suvarnabhumi International Airport, Thailand, between June and July 2025, and analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). The results indicate that EVL and GISM significantly enhance both PNA and PEF, which in turn exert strong positive effects on OC and OS. PNA emerges as the strongest predictor of both participation and financial commitment, highlighting the central role of moral obligation in motivating carbon offset behavior. While TRP significantly strengthens personal moral norms, its direct effect on Perceived Effectiveness is not significant, suggesting that trust primarily operates through ethical pathways rather than cognitive evaluations of program effectiveness. By distinguishing between participation decisions and spending behavior, this study extends VBN theory to the context of carbon offsets in aviation and demonstrates the mediating roles of moral norms and Perceived Effectiveness in translating environmental values and social identity into compensatory climate action. The findings offer practical implications for airlines and policymakers, emphasizing the importance of moral framing, transparency, and social identity engagement to promote voluntary carbon offset adoption in emerging carbon markets.