The WTA/WTP disparity in environmental and ecosystem services valuation
环境与生态系统服务价值的WTA/WTP不对称

Willingness to pay (WTP) and Willingness to accept (WTA) are the main two measures when using contingent valuation method (CVM) for valuation of environmental goods and ecosystem services, however, in most CVM cases there does exist a significant disparity between the two measures. Taking an urban river in Shanghai as a case, this paper using CVM values the ecosystem services of the river in both WTP and WTA measures. The comparative study of the two measures shows that, (1)There clearly exists a disparity between WTA and WTP, with a WTA/WTP ratio of 7.02, which is very consistent with some lastly international study results; (2)There is no significantly relationship between WTA and some important social-economic variables of respondents such as income, but WTA clearly related with population of respondents family, and education level, especially there is a remarkable relationship between WTA and WTP, all this indicates that the WTA may be a appropriate measure to value environmental change; (3)The WTA/WTP disparity may be caused by respondents income and education level, the WTA/WTP ratio is positively related with education level while negatively related with income of respondents. One important environmental management implication for the WTA/WTP disparity is that, when the same degree of quality or quantity of environment or ecosystem is changed, the welfare loss caused by damage or pollution will be many times greater than the welfare gain brought by protection or restoration.