【作者】 赵莉；

【导师】 顾海英；

【作者基本信息】 上海交通大学 ， 应用经济学， 2016， 博士

【摘要】 自从转基因作物商业化种植以来,转基因作物种植面积持续迅速增加。2014年全球转基因的种植面积已从商业化伊始的170万公顷增长至1.8亿公顷,扩大了100倍以上。当前,中国已种植了390万公顷转基因作物,全球排名第六。转基因技术在农业生产应用中得以迅猛发展的同时,转基因农产品在科学上的不确定性和信息上体现的不对称性引发了公众的争议,强烈要求政府能承担起监管转基因农产品的责任。论文基于转基因农产品的发展态势、社会认知及监管需求,利用实验经济学方法获取消费者对转基因农产品和非转基因农产品的拍卖竞价数据,以标签为导向,从减少信息不对称和保障消费者知情权的角度满足消费者的监管需求,以消费者福利最大化为立足点,分析转基因农产品的标签政策对消费者福利的影响;在此基础上,运用经济学理论与方法从动态博弈视角探究转基因农产品企业与非转基因农产品企业的定价策略及完美贝叶斯分离均衡,以寻求依靠市场力量实现监管目标;然后从激励相容视角剖析转基因农产品生产者的信用决策机理,试图从经济学角度营造激励相容条件,促使转基因农产品企业的理性选择转为诚信生产,进而有效控制生产者的机会主义行为,落实消费者的监管需求;最后提出相关政策建议。首先,在介绍了转基因农作物的商业化种植情况以及美国、欧盟和中国的监管政策后,依据《中国重要报纸数据库》2010-2014年期间重要报纸有关转基因农产品的报道,揭示转基因农产品有关争论背后的事实,探索消费者对政府监管的需求。其次,运用经济学实验数据,通过结合Matlab数值拟合与极大似然法估计出消费者对转基因苹果的态度的概率密度函数,模拟结果表明修正的K分布优于以往文献中常设定的均匀分布。继而计算消费者在自愿标签政策和强制标签政策下的福利差异。研究发现:当市场分离成本较高时自愿标签政策显著优于强制标签政策;当市场分离成本较低时,强制标签政策未能如预期般的优于自愿标签政策。再次,基于信息不对称和科学不确定,构建一个典型消费者和双寡头厂商的动态博弈,采取逆向归纳法先以效用最大化为原则求解消费者问题,再依据利润最大化为原则求解生产者问题,进而求解该博弈的完美贝叶斯分离均衡,并分析双寡头农产品企业的定价策略。结果显示:存在两个完美贝叶斯分离均衡,且转基因农产品价格显著低于传统农产品的均衡价格,而转基因农产品厂商与传统农产品厂商定价策略呈策略互补。当传统农产品均衡价格低于基本效用时,较高的转基因农产品价格与传统农产品价格组合为最优的完美贝叶斯分离均衡;相反,则较低的转基因农产品价格与传统农产品价格组合为最优的完美贝叶斯分离均衡。实际上,当传统农产品与转基因农产品之间的差异度足够大时,转基因农产品价格将高于基本效用,此时最优的完美贝叶斯分离均衡为较低的价格组合。最后,构建一个应用性更为广泛的委托代理模型,将政府监管密度、消费者维权意识、供应链诚信状况和追溯体系精确度等考虑在内,然后聚焦转基因农产品企业的激励相容约束条件,探讨如何缓解因生产商的机会主义行为引致的农产品安全问题。研究显示:促进激励相容机制的实现,可以采取加大政府监管密度与力度、提升供应链诚信水平和消费者维权意识以及完善农产品追溯体系等手段。本研究的贡献主要体现在:在研究中国转基因农产品标签政策对消费者福利的影响时,运用修正Kumaraswamy分布替代以往文献中普遍使用的均匀分布函数,而且强制标签政策与自愿标签政策下的修正Kumaraswamy分布函数形式是根据实际的拍卖数据模拟得出,而不是像以往大多数文献假设两种政策下消费者对转基因农产品的态度遵循同一个均匀分布;在研究双寡头农产品厂商的定价策略时所构建的典型消费者模型中考虑了转基因农产品具有的科学不确定性,并将科学不确定性简化为一种具有既定期望和方差的风险;在研究政府监管、消费者维权对农产品企业的信用决策的影响时所构建的委托代理模型中将政府监管密度、消费者维权意识、供应链诚信状况和追溯体系精确度等考虑在内。更多还原

【Abstract】 Transgenic technology has become one of the most rapid applied technologies.From 1996 to 2014,planting areas of GM crops have increased by more than 100 times and up to 181.5 million hectares.In 2014 China has planted 3.9 million hectares of transgenic cotton and papaya and 7.1 million farmers have planted genetically modified(GM)crops with $1.6 billion of output values.The expansion of GM crops is overwhelming.However,the public appeal for the regulation on GM product from the government due to the scientific uncertainty and asymmetric information of GM product.Based on the attitude and the status of the domestic reports on GM products,to use the method of experimental economics to obtain consumers’ auction bidding price on GM product and GMO-free product,and analyze the impact of labeling policy on consumer welfare;After analyzing the consumers,to use the theory and method of economics to study the separating perfect Bayesian equilibriums and the pricing strategy of the firms of GM product and GMO-free product from the perspective of dynamic game.Furthermore,to analyze the credit decision mechanism of the GMO-free product firm from the perspective of incentive.Finally,to summarize and puts forward to policy suggestions.First,following the research themes,according to the reports on GM products in the important newspaper in "Chinese important newspaper database" from 2010 to 2014,it reveals the fact behind the GM product debates and consumers’ demands for the supervision.Second,based on data from our economic experiments,the probability density function of consumer attitudes towards genetically modified apple is estimated using Matlab Numerical simulation and maximum likelihood method.By comparing the adjusted Kumaraswamy distribution with the Uniform distribution,we find that consumer attitudes in our experiments do not follow the Uniform distribution but instead fit an adjusted Kumaraswamy distribution.Moreover,consumer welfares under the voluntary labeling and the mandatory labeling regimes are calculated,which show that voluntary labeling is superior to mandatory labeling with the higher separation cost,while mandatory labeling is not necessarily better with lower separation cost.Third,in the context of imperfect competition,incomplete information and scientific uncertainty,a dynamic game with a typical consumer and duopoly firms is built.According to the backward induction,at first we solve the problem of the typical consumer based on the principle of the utility maximization,and then solve the problem of firms based on the principle of the profit maximization.After the separating perfect Bayesian equilibriums are deduced,we focus on the pricing strategy of duopoly firms.The results show that there are two separating perfect Bayesian equilibriums in which the price of the conventional product is significantly higher than that of GM product and the two prices are strategic complements.The larger separating perfect Bayesian equilibrium is the first-best solution if the price of the conventional product is low enough;otherwise,the smaller equilibrium is the optimal solution.In fact,when the difference between the conventional product and GM product is large enough,the price of GM product is higher than the basic utility and the smaller separating perfect Bayesian equilibrium is the first-best solution.Finally,taking the government regulation,consumer rights protection consciousness,the honest condition of supply chain and the degree of accuracy of traceability system into account,a principal-agent model with more wide applicability is constructed.Based on the incentive compatibility constraint condition of GMO-free firms,we discusse how to ease food problems due to the firms’ opportunism behaviors.Results show that the incentive compatibility mechanism will be promoted by improving the density and strength of government regulation,the honest level of supply chain,consumers’ rights consciousness and the agricultural product traceability system.The innovation of this study is listed as follows: First,when analyzing the impact of GM product labeling policy on consumer welfare,we use the adjusted Kumaraswamy distribution instead of the Uniform distribution commonly used in the past literature.Additionally,the PDFs under the voluntary labeling and the mandatory labeling regimes are estimated by the actual auction data respectively,which is different from the past literature to assume that the consumer attitudes towards GM product under the different regimes follow the same Uniform distribution.Second,in the study of the pricing strategy of duopoly firms,scientific uncertainty is taken into account and viewed as a risk with a given expectation and variance.Finally,when analyzing the effect of the government regulation and consumer rights protection on the honest decision of product firms,a principal-agent model considering the government regulation,consumer rights protection consciousness,the honest condition of supply chain and the degree of accuracy of traceability system is constructed.更多还原