条件价值评估法的发展与应用

环境物品或生态系统服务的经济价值评估是国际上生态经济学、环境经济学研究的前沿领域。由于绝大多数环境物品或生态系统服务的公共物品特性，其经济价值的评估需要运用非市场的价值评估技术。条件价值评估法（CVM）是非市场价值评估技术中应用最广、影响最大的一种方法。详细介绍了国际上CVM及其发展与应用研究的现状，分析了CVM在环境价值评估技术中的地位及其理论基础，总结了最大支付意愿（WTP）的各种引导技术，全面归纳了CVM研究中可能出现的各种偏差及其相应的解决方法，简要介绍了最大支付意愿的数据统计分析方法。

THE UPDATED DEVELOPMENT AND APPLICATION OF CONTINGENT VALUATION METHOD (CVM)

    The proper valuation of non-market environmental commodities has significant policy implications. Environmental valuation is also important in the event of natural disasters, either man-made or naturally occurring.  The economic valuation of non-market environmental goods or ecosystem services has been becoming a research frontier and hotspot field of ecological economics and environmental economics. Non-market valuation techniques should be applied to measure their economic value because of the public goods properties of most environmental goods or ecosystem services.
    Non-market valuation techniques can be broadly classified into two categories: revealed preference (RP) approaches and stated (or expressed) preference (SP) approaches. Stated preference methods attempt to elicit environmental values directly from respondents using survey techniques, hence the alternative name of “direct approach”. Stated preference methods can be further classified into two categories: contingent valuation method (CVM), and choice experiment. The CVM is the most significant approach of non-market valuation technique and has been using most widely. 
    CVM is a direct interview approach that can be used to provide acceptable measures of the economic value of environmental goods or ecosystem services. The CVM uses interview techniques ask individuals to place values on environmental goods or ecosystem services. The term “contingent” in CVM suggests that it is contingent on simulating a hypothetical market for the good in question. The most common approach in the CVM is to ask individuals the maximum amount of money they are willingness to pay（WTP）to use or to preserve the given good or service. Alternatively, the respondents could be asked the minimum amount of money they are willingness to accept in compensation (WTA) to forgo the given environmental good or service. Theoretically, these two measures should be equivalent. However, some empirical studies have indicated that WTA estimates exceed WTP estimates, this is maybe due to the feelings that the cost they loss the given good or service is more than the benefit they get the given good or service.
    This paper introduced the concept of CVM and the status of its development and application, analyzed the significance of CVM in environmental evaluation methods and its theoretical underpinning, summarized the available elicitation techniques or the question formats that acquire maximum WTP, assembled together various biases and their solutions, and introduced briefly the statistical analysis methods of contingent valuation (CV) survey data, especially the dichotomous choices data.
    In recent years, increasing attention has been given to the statistical aspects of CV survey design and data analysis. The main reason for the growing interests in statistical issues is the shift in CV practice from using open-ended question to ask about WTP to using a close-ended question format. With the close-ended question format, the CV responses are not money amount but answers of “yes” or “no”, and one obtains a WTP value from these responses by introducing a statistical model that links them to the money amounts that people faced in the survey. 
    The theory and practice research of CVM in China was almost equal to naught. Finally, the urgent research need of CVM in China was pointed out because of the need of green environmental and economic accounting and sustainable development assessment.