Economic assessment of ecosystem services with a novel concept of elevation: An application of the discrete choice experiment method

This research was conducted in the Hei River Basin of China to understand respondents' willingness to pay (WTP) for ecological services towards sustainable river system management. A discrete choice experiment is used to gauge respondents' preferences. In addition, elevation was introduced as a novel spatial attribute to account for heterogeneity. Primary data from 1680 respondents were collected across the Hei River Basin. The elevation of the river was categorized into five ad hoc elevation ranges to analyze the potential effects of elevation on environmental attributes. These samples were stratified as 1000-1600 m, 1601-2200 m, 2201-2800 m, 2801-3400 m, and 3401-4000 m. Pooled data results showed that the maximum WTP was for water quality, that is, 142.05 RMB, without considering the effect of elevation. However, when the interaction with elevation was included, the amount decreased to 133.52 RMB. Likewise, elevation-based group estimates showed a varied pattern of spatial preference, with different preferences for each distinguishing attribute. Group A prioritized water quality (92.81 RMB) and the East Juyan area (4.12 RMB). In contrast, Group B preferred the guaranteed rate of irrigation of farmland (3.50 RMB) and reduced sandstorm frequency (17.90 RMB). Leisure and entertainment conditions had the lowest WTP across all groups (0.09-0.50 RMB). These findings highlight the importance of incorporating respondents' preferences in restoring and maintaining river systems. Additionally, it emphasized the need to consider respondents' socioeconomic characteristics when developing sustainable management policies.