Environmental Culture and Willingness to Pay for Clean Air: A Cultural Additivity Perspective and Bayesian Mindsponge Method

Urban air pollution has become a critical governance challenge for many developing cities, where sustained air quality improvement depends not only on pollution-control capacity but also on durable public participation and financial support. Building on Cultural Additivity Theory (CAT), this study employs Bayesian Mindsponge Framework (BMF) analytics with a Bayesian cumulative ordinal logistic specification to investigate how environmental perceptions, adaptive behavior, and household financial capacity are associated with household willingness to pay (WTP) for urban air quality improvement, using survey data from 604 households in Hanoi, Vietnam. The results show that household income, perceived pollution urgency, perceived pollution impact, and avoidance behavior are positively associated with higher WTP. More importantly, the positive associations of perceived pollution urgency and avoidance behavior with WTP are more pronounced at higher household income levels, indicating that these environmental orientations are more closely associated with higher contribution preferences at greater levels of financial capacity. These findings suggest that household WTP reflects a differentiated decision process in which environmental engagement and material circumstances jointly correspond to stated financial contribution rather than operating as isolated determinants. This study makes three contributions. First, it extends CAT into behavioral environmental economics by distinguishing environmental value formation from its expression in stated financial contribution and revealing within-decision differentiation across environmental attributes. Second, it extends the application of BMF analytics to payment card WTP data through a Bayesian cumulative ordinal logistic specification that supports posterior and probability-based interpretation. Third, it provides evidence for designing clean air governance that combines locally relevant risk communication and behaviorally informed public engagement with flexible participation arrangements that recognize heterogeneous household financial capacity.