什么决定中国食品价格变动:供给抑或需求——基于随机波动时变参数模型

What Determines the Fluctuation in Food Prices in China:Demand or Supply?Based on Stochastic Volatility Time Varying Parameter Model

文章使用食品价格、肉蛋奶消费量、农业生产资料价格指数、受灾面积以及货币供给等变量,建立随机波动时变参数(SV-TVP)模型,通过Bayesian Gibbs Sampler方法估计模型参数的动态变化规律,对1994-2012年我国食品价格上涨的决定因素进行动态分析。结果显示:首先,自1994年以来的四次食品价格大幅上涨均以农资价格上涨推动为主;其次,只有出现较大的自然灾害才有可能影响食品价格,而一般的自然灾害对食品价格难以造成影响;再次,需求因素只能在长期造成食品价格缓慢上涨,不会造成食品价格的短期快速上涨;最后,超额货币对食品价格的影响虽然在统计学意义上显著,但实际的影响程度非常小。文章还提出了一系列稳定食品价格的对策建议,如提高流通效率、对农业生产资料退税、鼓励土地适度规模经营、促进农业科技创新、大力发展农业机械化以及逐步建立农产品目标价格制度等。

This paper establishes a stochastic volatility time varying parameter(SV-TVP)model using the variables of food prices,meat-egg-milk consumption,price index of agricultural means of production,disaster area and money supply,and employs Bayesian Gibbs Sampler method to estimate the dynamic change rules of parameters.And then it makes a dynamic analysis of the determinants of the increase in food prices in China from 1994to2012.It comes to the conclusions as follows:firstly,since 1994,four times of dramatic increase in food prices are mainly driven by the increase in prices of agricultural means of production;secondly,except the severe natural disasters,common natural disasters are difficult to have impacts on food prices;thirdly,demand leads to slow increase in food prices only in the long term,and cannot lead to a rapid rise in the short term;fourthly,although excess money has the statistically significant effect on food prices,actually it has only weak effects.In the end,it offers some advices for the stabilization of food prices such as the improvement of circulation efficiency,tax rebate of agricultural means of production,the advancement of appropriate land scale management,the promotion of agricultural technology innovation,vigorous development of agricultural mechanization and gradual establishment of target price system of agricultural products.