A Comparison of Direct and Indirect Methods for Estimating Environmental Benefits
比较了直接和间接两类方法估算水质改善带来的休闲效益，发现结果相当，但分析师的判断对两种方法都很重要。
Abstract Two classes of methods are currently available to estimate consumers' valuations of improvements in environmental resources—direct and indirect. This paper reports the results of a detailed comparison of the estimated recreational benefits associated with water quality improvements using one member of each class. The findings indicate that while the estimates are quite comparable, analyst judgment played a very important role in the development of both methods.