Protest Responses in Contingent Valuation Method for Coral Reefs in Kerama Islands

Abstract

The purpose of this paper is to estimate the value of the coral reefs in the Kerama Islands in Okinawa and to clarify the reasons for biases in the responses to the questionnaires. This research was conducted at Zamami village in March 2003, and the respondents to the questionnaires were passengers on ships between Naha and Zamami. The questionnaire is based on “Contingent Valuation Method” (CVM), which is used to evaluate the non-used value of the environment. In this questionnaire, we used the “double-bounded two-choice approach” in order to determine the passengers' willingness to pay (WTP) for the conservation of Kerama's coral reefs.Coral reefs are very important resources for ecology and the economy, especially in island areas like Okinawa. They have several public functions that provide material and spiritual benefits to human beings with regard to fisheries, ocean biodiversity value, purification of the ocean, underwater views, coastal protection, resources for tourism and recreation and so on. Recently, however, the drastic changes in certain environmental conditions have caused considerable damage to the coral reefs. We should recognize the necessity of protecting the coral reefs in order to retain their public functions; hence, we attempted to define the value of conservation of the Kerama coral reefs.First, we estimated the passengers' WTP for the conservation of the Kerama coral reefs, using the Turnbull method, which is a type of survival analysis. The results revealed that the average WTP per person was 3, 995 yen, and the total value for the annual passengers traveling to Zamami village was 367, 488, 065 yen per year.Second, we considered protest responses in order to assess the reliability of CVM as a method of evaluating environmental value. A total of 94 protest responses were obtained in this research, and we analyzed the reasons for which the respondents expressed objections to the scenario presented in this questionnaire. We clarified four factors: The method of payment, the taxable, the area of conservation, and the misunderstanding of the scenario presented. Closely performing a pre-test can solve some of these problems.While CVM is one of the small-number methods that can measure the non-used value of the environment, such as biodiversity conservation, its results are debatable due to its hypothetical character. Therefore, we will continue to examine the reliability of CVM by repeating this research.