Psychological distance and physical distance induced residents' heterogeneous willingness to pay for transboundary watershed ecosystem services in the Wei River Basin, China.

Under the framework of payment for transboundary watershed ecosystem services (ESs), identifying midstream and downstream residents' preference and willingness to pay (WTP) for ESs provided by the upstream is crucial for sustainable watershed management. The residents' preferences and WTP are not evenly distributed within the watershed. This study uses a choice experiment assessing the spatial impact of physical distance (including residents' watershed location and distance to waterbody) and psychological distance on residents' preference and WTP for the Wei River Basin ESs. The results showed that midstream and downstream residents' preference and WTP for the ecological attributes have a significant distance-decay effect, either the physical distance to the upstream exit or physical and psychological distance to the waterbody. However, compared with the residents in the midstream, the residents downstream have a stronger preference and WTP for upstream ecological governance. Besides, the distance-decay effect differs between urban and rural residents. There is a psychological distance-decay effect in rural residents' preference for water quality and a physical distance-decay effect in their preference for water quantity, entertainment area, and cost; there is a physical distance decay effect in urban residents' preference for entertainment areas. The above differences lead to heterogeneity in WTP and total economic value (TEV) for ESs. When calculating the TEV of the transboundary watershed ES and charging the public, policymakers should consider the location of the residents, the physical and psychological distance to the water body, and the difference between urban and rural areas.