the impact of different approaches of questionnaire eliciting on the willingness to pay in contingent valuation methods (case study: arasbaran forestst ecosystem)

consumers’ willingness to pay for nonmarket commodities such as wildlife, quality of the environment and forest services (including timber production, water conservation, soil conservation, oxygen supply, carbon sequestration, recreation services and wildlife preservation) is a measure of value of these resources. in recent years the contingent valuation has been used to determine this and other economic values by economists and policy makers. using different elicitation methods in contingent valuation yields different willingness to pay measures. so, it is important to determine which method is preferable. the objective of this study is comparing estimated preservation value of arasbaran forest ecosystem using open-ended and close-ended elicitation methods. in this paper, elicitation method were changed, ceteris paribus such as attributes of the commodity under valuation, socio-economic demographics of respondents, population, number of respondents and the payment vehicle, and based on these assumptions the results have been analyzed. data for this study is collected from 13 provinces using 509 questionnaires and logit and tobit models are used to econometric analysis of close-ended and open-ended data, respectively. results showed that some significant variables are different in two models; and also estimated willingness to pay using close-ended (112670 rials) is more than that in the open-ended (102700 rials) format.