Calculating and testing cultivated land protection externality using Contingent Valuation Method

This paper proposed the Contingent Valuation Method (CVM) for estimating cultivated land protection externality. The proposed CVM was based on reconstruction of cultivated land utilization benefit system and defined cultivated land protection externality. The paper discussed in detail specific techniques of sample size and distribution, determination of leading technology, pay/compensation interval setting, hypothetical market scenario setting, evasion of deviation, pretreatment of survey data, and results validity/reliability tests. The results showed that ecological and social benefits of cultivated lands included public goods with mixed classes across categories. These classes were provided by joint ventures between the pure positive externalities and the private sector (mainly farmers). This could be estimated by using CVM and other non-market valuation methods. The willingness to pay of interviewee for this service was heavily restricted and influenced by their levels of socioeconomic development. The recognition of ecological and social benefits of cultivated lands of farmers and urban residents formed the main causality factor for the differences in payment ratio between urban residents and rural farmers. Urban residents were more familiar with ecological and social benefits of cultivated lands than rural/farm households. This was probably a key factor influencing the willingness to pay for ecological services. Farm households preferred voluntary labor as mean of payment, while both money and voluntary labor were more preferred by urban residents. The probable reason for this was that farm households had more leisure time than urban residents. Unitary cultivated land protection externality for Jiaozuo City was 1.91×10⁸ Yuan·a^-1 and the cultivated land protection externality per unit area of cultivated land was 993.7 Yuan·hm^-2·a^-1 base on CVM. CVM validity and reliability test was a critical element of CVM theory, method and practice. This was obtained through questionnaire optimization, pre-survey, questionnaire revision, rational inquiry, comparative analysis of different estimation methods, and repeated tests of the same method. The test results showed it was reliable and valid to use CVM estimating the cultivated land protection externality.