我国蔬菜田头价格剧烈波动的农户种植行为非对称调整策略研究

The abnormal price fluctuations of vegetable occurs frequently, the phenomenon of low-priced vegetable hurting the peasant and high-priced vegetable hurting the people ofen takes place, it has been the focus in China recent years. Once the original vegetable price fluctuates violently, asymmetric responses and adjustments will be produced in the vegetable farmers planting choices. This subject researches asymmetric adjustment and strategy of the original vegetable price fluctuations based on the vegetable farmer planting behavior perspective, applies game theory model, discrete choice model as well as structural equation model approach, takes the main line of “price fluctuations -asymmetric adjustment of the vegetable farmer planting behavior-factor analysis-policy simulation-policy suggestion". Primary coverage: (1) Establishing the discrete choice model, analyzing whether or not the farmers adjust their planting behavior;(2)Constructing structural equation model, analyzing the factors of the asymmetric adjustment in the vegetable farmers planting choices;(3) Constructing the subjective game model between vegetable farmers and wholesalers, analyzing the factors of the asymmetric rising and slump in the vegetable price; (4) Researching the effect of vegetable price insurance and adjustment fund on vegetable price fluctuation;(5)Investigating and analyzing the two policy effect and policy evaluation, verifying the hypothesis and proposing the appropriate policy recommendations. This research can further improve the theory and method of price fluctuation of vegetable, and has great value to steady the China price fluctuation of original vegetable, safeguard the people's livelihood and coordinate the interests of vegetable producers and operators.

近年来我国蔬菜价格涨跌频现，“菜贱伤农、菜贵伤民”现象时有发生，蔬菜价格异常波动时常成为关注焦点。一旦蔬菜田头价格剧烈波动，菜农的种植选择就会产生非对称反应和调整现象。本课题从菜农种植行为的视角，以蔬菜田头价格剧烈波动为主题，借助主观博弈模型、离散选择模型、结构方程模型等方法，以“价格剧烈波动-菜农种植行为非对称调整-影响因素分析-政策模拟-政策建议”为主线，研究蔬菜田头价格剧烈波动的农户种植行为非对称调整策略问题。主要内容：（1）构建离散选择模型，对菜农对蔬菜种植选择调整与否的关键影响因素进行分析；（2）构建结构方程模型，分析菜农种植行为非对称调整的关键影响因素；（3）构建菜农和批发商的主观博弈模型，分析蔬菜田头价格长期涨跌非对称的影响因素；（4）研究蔬菜价格保险和价格调节基金对蔬菜价格波动的影响；（5）调研分析两种政策的效果，进行政策评估，验证理论假设并提出恰当的政策建议。

近年来我国蔬菜价格涨跌频现，“菜贱伤农、菜贵伤民”现象时有发生，蔬菜价格异常波动时常成为关注焦点。蔬菜田头价格剧跌，势必会对菜农的收入造成影响，如何缓解菜农损失，减少价格波动幅度，就成为政府迫切需要解决的问题。.本项目重点研究了：（1）蔬菜价格的非对称波动现象。首先，本文从运用Census X12季节调整法和H—P滤波法对蔬菜价格波动的特征进行分解，分离出季节性要素、趋势性要素、周期性要素和不规则要素四个价格波动要素的特征及其对蔬菜价格波动的影响，并对不同蔬菜表现出的价格波动特征进行比较分析；其次运用ARCH类模型研究外部冲击对蔬菜价格整体波动的影响；最后得出结论。（2）菜农面对蔬菜价格剧烈波动的非对称调整现象。首先，构建了离散选择模型和结构方程模型，发现菜农种植行为对蔬菜价格波动的反应并不敏感。传统观念认为，菜农对蔬菜种植选择的调整最为关键的影响因素是价格波动，本研究发现菜农对蔬菜价格波动的反应并不显著，反而对其他影响因素有着明显的相关性，如：菜农的身体状况、蔬菜本身的亩产量，常年种植某种蔬菜的惯性等影响因素；这对本项目来讲是一个新的发现，出于对本结论的可靠性，项目负责人正在进一步加大调研的范围和样本量，从而进一步验证结论是否正确，如果结论正确，关于解决我国蔬菜价格剧烈波动的政策方向则需要改变，不应把目标仅仅放在市场的供求方面，而是应该把目标放在农户本身，应努力提高菜农自身素质等方面。（3）构建了菜农和批发商的主观博弈模型，发现菜农作为弱势群体往往会选择妥协，而批发商则往往采用抱团策略攫取更多的利润。