Construction and Empirical Study of Trend Surface for Willingness to Pay Based on Improved Voronoi Method
International Journal of Smart Home
The study on spatial attributes of willingness to pay(WTP) is meaningful for cost sharing of environmental goods recovery. This paper forces on the rules of spatial variation of willingness to pay in different areas, by division of sub-area and construction of trend surface. It is divided 71 sub-areas by Voronoi Polygon and constructed trend surface of willingness to pay for each sub-area for the non-use value of Songhua River as a study case. The result shows that high WTP areas spatially
... reas spatially aggregated around the environmental goods, as low WTP areas dispersed on both sides of the environment goods uniformly. Which influenced the WTP is not only the distance, but the degree of understanding and the use of environment goods, interpretated by Probit models. It's an easier and faster method for the trend surface construction, which has a significant value for the study of spatial attributes of willingness to pay. 116 Copyright ⓒ 2016 SERSC quality improvement of American rivers by CVM , first advanced distance decay effect, and established a signal dimension model for it and visit frequency, the model result shows the significant correlation between them, i.e. the residents farther away from a river is less likely to visit the river. Some later studies show that the quality demand of respondents for an environmental article decreases with the increase of their distance from the environmental resource. Some studies conclude that "distance decay effect" needs special experimental design and model design, and all cases can't show such character  . After Sutherl and Walsh (1985) , a lot of studies center on the discussion about distance decay effect in different scales, involving verification of distance decay effect, application scale of distance decay effect, influencing factor of distance decay effect and so on, and most research methods center on the modeling of different experimental designs or different scale variables  . Model studies simply discuss the negative correlation between distance variable and WTP, seldom apply GIS data, gridding and other methods, and lack spatial visualization study. If an environmental article is river, the cost sharing study of its habitat improvement also centers on distance decay effect. Related study shows that, as to the WTP for quality improvement of river water, nonusers of resource show strong distance decay effect, but the researchers didn't measure the degree of WTP difference between users and nonusers  . A study defined "user" and "non-user", and discovered the obvious influence of the two kinds of respondents on structural model. Meanwhile, a study denies the conclusion above, and thinks the users are insensitive to distance change, and only nonusers can take on strong distance decay effect  . Songhua River, one of the most important rivers and with the widest drainage basin in Northeast China, surely attracts our attention to the spatial attribute of WTP for its water quality improvement. By improved Voronoi model, the paper provides a construction method of WTP trend plane, and makes statistical analysis for the regional data of WTP. Spatial attribute of WTP is studied by Moran's Index of trend plane, and influencing factors of spatial attribute of WTP are studied in combination with Probit model. Take non-use value of Songhua River as object of study, the applicability of trend plane construction method is verified. Trend plane of WTP has the characteristics such as small calculated amount, simple application, visible result and convenient analysis. For specific WTP study case, the method widely applies to different research scales and different regional division methods.