Economic Value of Water Quality Improvement by One Grade Level in Erhai Lake: A Willingness-to-Pay Survey and a Benefit-Transfer Study

摘要

Water quality in China has seriously deteriorated in recent years. However, very few valuation studies have been conducted to estimate the monetary values associated with water quality changes. As a result, the decision makers can hardly make rational choices with regard to investments in water quality improvement. This paper presents a valuation study conducted in Dali, Yunnan Province, which aims to estimate the total economic value of improving the water quality of Erhai Lake by one grade level. Both the contingent valuation method and the benefit transfer approach are employed in this study. The contingent valuation estimation strategy reveals that, on average, a household located in Dali is willing to pay about 27 yuan per month continuously for 5 years for the water quality improvement, equivalent to 1.7% of the household monthly income. The elasticity of willingness-to-pay with respect to income is estimated to be 0.28. The internal rate of economic return of the proposed pollution control project is estimated to be 13%. The benefit transfer exercise produces a similar estimation on willingness to pay (WTP) values, with a difference of less than 2% compared with the contingent valuation approach. The results indicate the potential reliability of using the benefit transfer approach for valuation estimations in Chinese provinces.