Public willingness to pay for coastal protection infrastructure: Benefit-cost trade-offs, risk attitudes and spatial proximity

Large-scale public coastal protection infrastructure is increasingly required to safeguard densely developed urban areas from rising flood risks associated with sea-level rise and more frequent extreme weather events. Such investments impose costs on the public in the present while delivering benefits primarily through reduced future risk, making public support critical to political feasibility and successful implementation. This study employs a choice experiment to examine public support for a planned coastal protection project and to analyse preference heterogeneity within an urban population. The approach enables explicit examination of the trade-offs individuals make between flood risk reduction, ecological impacts, inconvenience and project costs, and the identification of the factors that influence heterogeneity in willingness to pay, including risk attitudes and spatial proximity. Respondents place high value on flood risk reduction and limiting ecological damage, while construction-related inconvenience significantly reduces support. Individual attitudes towards risks and response measures, trust in government, and residential proximity drive considerable heterogeneity in willingness to pay among respondents. Furthermore, interaction analysis shows that spatial factors amplify attitudinal attributes. Those with higher flood risk perceptions living in proximity to the project express significantly higher support for flood risk reduction than others. These findings highlight the need to take into account attitudinal and spatial heterogeneity when assessing public support for climate adaptation and designing and funding coastal protection measures.