美国大豆加工贸易对我国大豆进口影响的实证分析——基于我国加入WTO以来的月度数据

Empirical analysis about effects of soybean processing and trade in USA on soybean import in China:Based on monthly data since China's entry into WTO

利用我国加入WTO以来的大豆贸易月度数据,采用季节调整、单位根检验等方法,研究美国大豆加工量(主要指压榨量)、出口量及其库存量与我国大豆进口量的关系。模型估计结果表明:美国大豆当月净出口量与我国大豆当月进口量呈显著负相关关系,这主要因为美国大豆净出口行为与我国大豆进口行为存在一定的时滞,滞后2期的美国大豆净出口量增加1 t,可导致2个月后我国大豆进口量增加0.24 t;美国大豆压榨量与我国大豆进口量呈显著的正相关关系,这可能因为各国大豆压榨需求存在一定的同步性,且其对我国大豆进口也存在一定时滞性。美国大豆及其豆制品的库存量会限制美国大豆出口能力,从而进一步影响我国大豆进口。

This paper explains the relations between soybean exports, crushes and stocks in USA and soybean imports in China by seasonal adjustment and ADF unit root test based on relative monthly data since China＇s entry into WTO. The results of models show that there exists a negative relation between monthly soybean net-export in USA and monthly import in China. That is mainly resulted by a kind of time-lag between the net-export of USA and the import of China. If the soybean exports in USA. increase by 1 t, the soybean imports in China will increase by 0.24 t after two months. Soybean crushing capacity in USA has a remarkable positive correlation with the import of China, maybe due to the synchronization for demand on soybean crushing capacities of main countries and the time-lag. Stocks of soybean and relative products in USA will constrain capacity on its export and further influence the import in China.