意愿价值法评估生态服务价值的有效性与可靠性及实例设计研究

Review on the Validity and Reliability of CVM in Evaluation of Ecosystem Service and a Case Design Study

意愿价值评估法(CVM)以新古典经济学需求理论为基础,通过构造假想市场使生态服务价值的评估成为可能。但是,经验研究中出现了与新古典经济理论及其预期不一致的异常现象,致使CVM的有效性与可靠性受到广泛质疑,而成为目前国际CVM研究的主要方向。对国际、国内CVM有效性与可靠性的研究进展进行了综述,重点梳理了国际上对WTP的内容依赖性、WTP与WTA的显著差异及可靠性与效益转移等方面的经验研究;而国内由于缺乏该方面的系统研究,制约了CVM在我国生态价值评估及环境公共政策制定中的应用。为此,在前期开展的实例研究基础上,设计了适合我国社会经济特征和生态环境特点的CVM有效性与可靠性研究的技术路线和多重调查方案,以期推动CVM在我国的进一步发展与应用。

Allocating appropriate funds to the provision of non-market public goods must be based on appropriately measuring the benefits gained. The Contingent Valuation Method （CVM） is a technique based on stated individual preferences, which has been extensively used for assigning monetary values to goods such as those provided by the ecosystem. But due to the hypothetical market it employs, the validity and reliability of the method has been controversial especially since 1993. This paper is a review on the above field： This paper can be divided into the following three parts. （ 1 ） CVM has been primarily developed：by economists and is founded on neo-classical demand theory. Its core assumption is that the preferences of consumers are stable. But the present abundant literature has shown that results of CVM often appear to be inconsistent with this core assumption and the expectations of economic theory. The dependence of CV outcomes on the hypothetical situation the respondent is to value （content dependence ） and the often large divergences between WTP-and WTA measures of benefits raise question about whether measured benefits in one study can be transferred to other locations or situations. This paper cites many CVM case studies to illustrate these anomalies and summarize different explanation ; （2） Based on a general review of CVM research in China, the authors points out that the absence of tests of validity and reliability will hamper the future application and practicality of cost-benefit analysis ; （3） The paper puts forward multiple schemes for establishing CVM＇s validity and reliability testing which are in accordance with the ecosystem characteristics and social structure particularities in China based upon a previous case study about the ecological restoration of urban river in Shanghai. The scheme provides some direction and suggestions for future research in China. Improving validity and reliability is the key for CVM to being applied in practice and to making a decisive input to policy-making. In spite of not reaching a conclusion it is a hot problem in developed countries but not in China. Despite the different social circumstance, further studies including this paper are necessary and urgent for the application of CVM in China.