上海池塘养殖环境成本——基于双边界二分式CVM法的实证研究

池塘养殖具有食品供给、空气质量调节、文化服务等多重功能,但在其生产过程中也会产生环境成本。正确认识池塘养殖的正、负生态服务价值,对于避免养殖生产过程中存在的盲目和短视、保持水产养殖业本身的可持续发展、促进水产养殖经济与环境的和谐发展具有重要的现实意义。依据双边界二分式CVM法,通过随机抽样调查法获得当地居民对于环境污染时的受偿意愿(WTA)水平,利用STATA10.0软件定量核算了2010年上海环淀山湖地区的池塘养殖环境成本为1982.26万元/a,约合5105元.a-.1hm-2)。研究表明,居民家庭收入、受教育程度、年龄等社会经济因素对居民的环境污染受偿意愿具有显著性的影响,但其具体的影响力大小和方向还有待进一步的探讨。研究同时表明,双边界二分式CVM法具有较强的稳定性,政府应综合考虑各种因素,制定并执行针对性、公平性的生态补偿政策。

Environmental cost of pond aquiculture in Shanghai: an empirical analysis based on double-bounded dichotomous CVM method

At present, academics on the ecological services value research focus on the positive aspects, while the negative service values, such as environment cost, is received little attention. Pond aquaculture performs multiple functions, including aquatic products supply, air quality adjustment as well as culture service and so forth. As a kind of special ecological system, the pond aquaculture also has the environment cost in its production process. A clear cognition of the positive and negative ecological services values in pond aquaculture will be a great significance to avoid the blindness and short-term version in the process of production, keep the development of pond aquaculture sustainable and promote the development of aquaculture in harmony with the environment protection. This paper firstly adopts double-bounded dichotomous contingent valuation method (CVM) and random cluster sampling method to attain the local residents' willing to accept (WTA), 354 questionnaires were sent out and 340 effective questionnaires were returned, the effective response rate was therefore 96.05%. Then the paper adopt Logit and Biprobit regression models of econometrics and STATA10.0 software was utilized for analyzing the environment cost of pond aquaculture in the DianShan Lake, Shanghai. Through these methods adopted, the paper has summarized these results as following: 1) The ecological compensation E(WTA) standard of Shanghai residents for the environment pollution damage is 104.89 RMB Yuan per person in Logit model and 121.89 RMB Yuan per person in Biprobit model; 2) In 2010, the total pond aquaculture environment cost is about 19.8226 million Yuan, namely 5105 RMB Yuan·a^-1·hm^-2); 3) The latest research released that several economic social factors such as the income of the household, education background and age lay a great influences on residents' willingness to accept the ecological compensation, but these factors will cause no strict trend influences on the residents' WTA at present. Such as the income of the household, education background of residents affect the E (WTA), which shows a positive effect on the relationship of E (WTA) standard. The 18-45 years old residents pay more attention to the environmental protection. If government takes the ecological compensation policy, they may be the main stakeholders. The paper also mentions the discussions: 1) Because these social economic factors have common influences on the E (WTA) standard of residents, but the size and direction of these influences are not absolute, it needs to do a further study based on the actual situation to establish a stable structure model to determine the size and direction of these influences; 2) By the LR and WALD test, the research indicates that the double-bounded dichotomous discrete CVM has a stronger stability than the single-bounded dichotomous discrete CVM, thus the double-bounded dichotomous discrete CVM can become a relatively stable research method for ecological system service value study; 3) The environment property right should be the applicable standard to WTA and WTP. Meanwhile, improving the questionnaire design accuracy, adjusting the research course etc can overcome the differences between WTA and WTP effectively; 4) Government should make and conduct a make-up policy for ecological compensation according to the real situation in order to achieve the environmental equity and sustainable development.