Double Border Dichotomous CVM Statistical Models Research And Application

The contingent valuation method (CVM) is availably, flexible nonmarket valuation method which is widely used to evaluate the environmental goods. The double bounded dichotomous choice is the most ective format of contingent valuation models and is widely used in the CVM。However, compared the payment card questionnaire form with Dichotomous CVM questionnaire, the dichotomuous CVM form is relatively complex in the calculation. It can not provide a direct estimate of the WTP and its parameter model can not fully fit the WTP as well as exploit the sample data information, must need to rely on subsequent statistical analysis to obtain the average willingness to pay. Parameter model assumes that the distribution of WTP is known; construct a statistical model based on the known and inferred distribution. The disadvantage is only concerned about the empirical distribution, failed to consider the possibility of other distribution. There are large differences between different distributions based on the estimated value of the resulting WTP, WTP estimates obtained lacks reliability and validity. However,non-parametric model for the distribution of WTP makes no assumptions, at the same time, avoiding to choose the WTP distribution of parameter model, can be very easy to get WTP estimation。It was be concerned because of the simplicity to calculate. However, comparing with the parameter estimation, the estimation of WTP obtained by the non-parametric model is quite different.Semi-Parametric model is an available model between Parametric model and non-parametric estimation. Currently more and moer academics concerned about it and try to be applied in CVM. However, the validity and reliability of the estimation results yet to be studied.This article summarizes the statistical model of dichotomous CVM.There are parametric model, semi-parametric model and non-parametric methods in the dichotomous CVM data for statistical calculations.Based on past studies, the double boundary dichotomous CVM parametric calculation model is divided into the WTP function model, random utility models and survival analysis methods, and detailed analysis those model of the processing building and calculation. The double bounded dichotomous choice is the most ective format of contingent valuation models except that it can not provide a direct estimate of the WTP and its parameter model can not fully fit the WTP as well as exploit the sample data information. This research provides a new path by addressing an analysis method of the CVM based on survival analysis and building a semi-parametric proportional hazards model to analysis the impact factors of willingness to pay. For it’s simple to calculate of non-parametric model, more and more scholars received this method. This paper presents non-parametric estimation turnbull, processing and analysis of survey data. Taking Sanjiang plain wetland landscape evaluation as an example, we use the above model for the investigation to get double boundary dichotomous CVM data processing and analysis.The paper used the WTP function model, random utility model and survival analysis method to analyze and calculate questionnaire data. The average WTP of the WTP function model is126.37Yuan per year and131.93Yuan per year. The average WTP of random utility model is135.05Yuan per year. The average WTP of weibull and logit in survival analysis method is126.24Yuan per year and147.02Yuan per year. Then constructed Cox proportional hazards model, the average WTP is110.33Yuan per year.The average WTP of turnbull estimation is108.01Yuan per year.The paper used parametric model, semi-parametric model and non-parametric methods to analyze affecting factors and risk factors of WTP.Male, age, income level, education level, the level of concerning and Satisfaction of the current environmental are important factors for the WTP of the wetland environment protection. At the same time, these proved the feasibility of the method of survival analysis in the CVM, expanded the calculation and analysis methods of CVM. Research enrich double boundary dichotomous CVM computing model that provides a variety of effective methods of computation willingness to pay, the assessment results will provide reasonable theory to develop policies for government.