환경자원의 가치평가체계 구축

Abstract

Abstract Building the Environmental Valuation System This study deals with the issue of the biases in the contingent valuation method (CVM) in environmental valuations, especially focusing to the hypothetical bias in CVM. Since the exactness of a value which is estimated by CVM is a cornerstone for a rational and efficient environmental policy through a cost-benefit analysis, it is a crucial issue to investigate if there is a bias in the value estimated through CVM. As a result, there have been great efforts to find and sort possible biases in CVM. A guideline published in 1993 by NOAA is a product of such efforts, and it effectively suggests the ways to reduce or eliminate various biases. However, it is rather silent for the reason and solution of the hypothetical bias which has been regarded as the most problematic one in CVM. In fact, the serious efforts to resolve the hypothetical bias has been exerted soon after the NOAA guideline published. Unfortunately, the reason of the hypothetical bias is not yet exactly known and hence there is no clear solution either. This study mainly attempts to suggest the reason and solution of the hypothetical bias while briefly summarizing the other biases. While the problem of the hypothetical bias is a fundamental and general one, there could still be a bias if a researcher using CVM does not follow the various suggestions from a the guideline to reduce many possible biases. Thus, this could be a practical problem in CVM. One of the purpose of this study is to investigate whether this kind of practical problem exists in various CVM studies done in Korea. Thus we tackle and combine two different but entangled issues - the issue of the hypothetical bias and the issue of how a CVM study in Korea is actually done - for the ultimate purpose of improving the validity of the valuation results from CVM. In chapter 2, we briefly summarise the bases and issues in environmental valuation including (1) why we have to value environmental goods, (2) what we mean by the concept of value, (3) why CVM is so important in environmental valuation, (4) what the procedure of doing a CVM study is, (5) what possible biases are in CVM (6) what the solutions for the biases which has suggested up to now are. In chapter 3, we collect data of environmental valuation studies using CVM in Korea and summarise according to the methodological aspects and the type of an environmental good. We find that some operations which has to be done in order to reduce a bias are largely neglected. For example, a few studies have still used a voluntary contribution to elicit a respondent’s willingness-to-pay (WTP) and many studies do not include enough information on the survey design and method. These findings would partly explain why a very similar valuation studies using similar methods gives significantly varied results and would cast a doubt to the credibility of the environmental valuations using CVM done in Korea. In chapter 4, we move to the fundamental problem in CVM: that is, the issue of the hypothetical hypothesis. After we sketch the candidates of the reason and solution on the hypothetical bias, we introduce a new view about the reason of it. We argue that the hypothetical bias may be a personality of an individual. Our experimental study partially proves this perspective: the hypothetical bias at WTP from CVM increases with that at risk attitudes. This result implies that censoring and removing respondents who is subject to the hypothetical bias is the only and ultimate way to eliminate the hypothetical bias in CVM while affirming the hypothetical incentive compatibility may be a eclectic way to reduce it. In chapter 5, we summarise the results in this study and suggests the contents with which should be dealt in a guideline for CVM. The guideline should comprehensively contain from the ways to resolve fundamental problems including the hypothetical bias to the ways to correct practical problems. We suggest some necessary contents which should be included in such a guideline. We believe that this list effectively summarizes the main results of this study and could be a cornerstone for a complete guideline for CVM.