Social Capital and Information Nudge Impact on Residents’ Willingness to Pay: Measures for Financially Sustainable Water Supply Services

This study examines how public acceptance of an increase in water rate can be enhanced to support financially sustainable water services. Using survey data from 1665 individuals in Japan, we analyse how information provision and social capital affect willingness to pay (WTP) by focusing on use and non-use values. The results show that non-use values play a central role in shaping WTP. In particular, values related to financial sustainability, disaster preparedness, and reducing burdens on future generations significantly increase WTP, whereas altruistic concerns for low-income households do not. We also find that information provision alone does not increase WTP. Instead, prior knowledge of water services is associated with higher WTP, suggesting that information is effective only when it is already internalised. Moreover, certain types of information can reduce WTP, such as messages emphasising individual losses, decrease WTP among respondents with prior knowledge. Finally, social capital significantly influences WTP. Trust, reciprocity, and interactions with neighbours increase WTP, while participation in community activities negatively affects WTP. These findings highlight the importance of social and informational factors in designing policies to achieve socially acceptable water pricing.