基于离散选择模型的水质改良非市场价值评估——以滇池为例

ESTIMATION OF NON-MARKET VALUE OF IMPROVING WATER QUALITY USING CHOICE MODEL——A CASE STUDY OF DIANCHI LAKE

关键词:  离散选择模型 非市场价值 水质改良 滇池

Key words:  discrete choice model  non market value  water quality improvement  Dianchi lake

摘要:

非市场价值的评估是水质改良项目经济可行性分析或水生态补偿决策必须考虑的难题之一。该文以滇池为例，通过选择卡和开放式问卷调查获得昆明市居民对滇池水污染的认识及对水质改良的支付意愿，利用离散选择模型估计了滇池水质改良的非市场价值，利用Tobit模型分析了影响对居民最大支付意愿的影响主要因素，其中将离散选择模型用于水质改良在国内尚属首次。结果表明，多数居民对水质水污染有较清晰好的认识，居民的支付意愿与家庭收入、目标水质、对项目的了解程度、对湖泊环境影响的认识等成正相关关系；居民户对四类水和三类水水质的支付意愿分别为每月42元/月和91元/月，或504元/年和1092元/年，分别占家庭年平均收入的011%和023%；因此，可以计算算得滇池目前的水质改良到IV类和III类的非市场价值分别是6 91996万元/年和1499 3亿元/年。研究具有以下意义：首先，非市场价值是水质改良价值的重要组成部分，在评估水质改良项目的经济可行性时应给予考虑；其次，在为水质改良项目进行公共融资时，应考虑到居民支付意愿的影响因素，并让居民更多地了解水质改良对湖泊生态的影响；最后，通过对环境产品或服务的定价，将弥补未定价稀缺性所带来的经济问题。研究结果可为水质改良项目可行性分析和生态补偿决策提供参考依据。

Abstract:

Non-market value assessment is necessary for analyzing economic feasibility of water quality improvement project or making water ecological compensation strategies. Taking Dianchi Lake, which located in Kunming Yunan province, as an example, this paper used the Selection Card, Open Questionnaire and interview methods to acquire local residents' awareness of pollution in the Lake and their willing ness to pay (WTP) for improving its water quality in Kunming. Then, the Random Selection Model was adopted to estimate non-market value of water quality improvement in Dianchi Lake, and the Tobit Model was utilized to analyze the influence of each factor on the respondents' WTP and find out which led the maximum WTP. It was the first attempt in China to use the Random Selection Model to make such estimation on water quality improvement. The results showed that most of the local residents had a comprehensive and clear understanding of water pollution in Dianchi Lake and local residents' WTP had significant positive correlations with household income, water quality target, understanding of this project, knowledge of the environment influence of lake pollution, and so on; the average WTP per household for improving water quality to meet the requirement of Level IV and Level III was 42 Yuan/Month and 91 Yuan/Month, respectively, or 504 Yuan/Year or 1092 Yuan/Year, accounting for 011% and 023% of their annual income. Therefore, the non-market values of water quality improvement to Level IV and Level III amounted to 692 million yuan per year or 1499 million Yuan per year. It concluded that: 1）Non-market value was a significant part in the water quality improvement and should be given careful considerations in the estimation of water quality improvement. 2）As for the public financed water quality improvement projects, local residents' wiliness to pay (WTP) needed to be taken into consideration as well, since the WTP largely depended on their knowledge of the influences on ecological system in lakes and rivers. 3）Another, which is. When the environmental and related services are priced, some economic problems due to the scarcity pricing can be solved. These conclusions can provide information for economic feasibility analysis of water quality improvement projects and ecological compensation, and then make contribution to certain policy making.