Exploring donation willingness for urban public parks in Vietnam through socio-demographic factors, motivations, and visitation frequency

Urban public parks are increasingly vital to sustainable city development, particularly in rapidly urbanizing countries like Vietnam. Yet, despite national policy efforts, many parks remain underutilized, underfunded, and neglected. This study investigates the factors influencing Vietnamese urban residents’ willingness to donate to planting projects in public parks, utilizing the Bayesian Mindsponge Framework (BMF), which combines Granular Interaction Thinking Theory (GITT)'s ’s informational entropy-based notion of value with Bayesian analysis. Based on survey data from 535 residents in major Vietnamese cities, we found that while men visit urban parks more frequently, they show less willingness to donate to planting projects. Older residents visit parks more often and are more willing to donate, while higher-income individuals show greater willingness to donate. Most motivations, such as relaxation, physical activities, nature enjoyment, socializing, and family time, are positively linked to park visit frequency and indirectly linked to donation willingness. However, only relaxation and enjoyment of nature are directly associated with willingness to donate. Interestingly, higher education levels and visiting parks for children’s educational activities are associated with lower donation willingness. These findings suggest the possible presence of free-rider behavior, gender inequality, and ineffective environmental education. At the same time, they suggest opportunities to cultivate an eco-surplus culture through interactive nature experiences in urban parks.