The Effect of Soybean Trade between China and the United States on Chinese Residents’ Consumption Expenditure—Based on 2004-2016 Trade Data

This paper uses cointegration analysis method to estimate the correlation between China’s per-capita consumption expenditure and the amount of soybean imported from the United States. It is found that importing soy from the United States can reduce China’s per capita consumption expenditure. There is a long-term equilibrium between the per capita consumption expenditure and the imports of soybean native to the United States. In the short term, one of them can have a lasting impact on the other.


Introduction
The supply of agricultural products has always been the basis for the survival of a country, and it is an important issue related to the national economy and the people's livelihood. In order to release agricultural resources and make up for the shortage of domestic agricultural products, a country will generally choose the import strategy to solve this problem. However, this strategy may make the domestic agricultural product market excessively dependent on the international market, the country lacks independence, and it will seriously cause the country to lack the right to speak. In recent years, China's imports of agricultural products have continued to increase; with soybean imports occupying a more important This paper will adopt a cointegration analysis model to empirically analyze the impact of soybean originating in the United States on the level of Chinese residents' consumption.

Literature Review
Most studies on soybean import and export at home and abroad have focused on prices (He Lei [1]

Data Description and Selection
This  Table 1. The difference between the original data variables is large, which is not conducive to statistical analysis; and after the logarithmic processing operations, the differences between variables are reduced, and the data is con-

Unit Root Test
In this paper, the unit root test is conducted on the logarithmic variables of household consumption expenditure, soybean import amount, soybean export amount originating in the United States, and soybean import amount originating in other countries to analyze its stability. The test results are shown in Table   2. From the results, it can be seen that all the original sequences of the variables are not stable at a significant level of 5%. After a first-order differential, it is significant at a 5% significant level.

Cointegration Test
The stationarity test shows that all research variables are first-order single integers, then the following will perform further cointegration tests on lnallconsumption, lnbeanimport and lnusabeanimport.
The test results in Table 3 indicate that both model (1) and model (2) are at a significant level of 5%, and there is a unique cointegration equation among the variables, which has a long-term equilibrium relationship. According to the test results and the sample size of the optimal lag period in the 11th model, the two test equations in this paper adopt the regression of the second-order lag. After normalizing the equation, you get: The results show that the soybean import amount will have a significant posi-

VECM System Stability Test
In order to ensure the rigor and validity of the model, we use AR root test to test the stability of model (1) and model (2). The AR root test is only a method used to check the stability of the system. When the eigenvalue is greater than 1, the system is unstable; otherwise, the system is stable. The details of the AR root stability test eigenvalue data in this paper are shown in Table 4: The eigenvalues of the two models are not greater than 1, i.e., no eigenvalue falls outside the unit circle, and the overall stability of the VECM (1) and (2) models. In order to observe the analysis results more intuitively, this article also shows the results of the judgment through graphic methods, as shown in Figure 2 and Figure 3.

Impulse Response Function
In order to further examine the relationship between soybean imports and per   capita consumer spending, the study period is set to 13 periods, and the use of impulse response function is further explored. Taking Figure 4 as an example, the line graph on the left side of Figure 4 is represented as follows: the relation chart between consumption expenditure as impulse variable and consumer expenditure as the response variable, the relation chart between soybean import amount as impulse variable and consumer expenditure as the response variable,  The three line graphs on the left represent the effects of fluctuations in consumer spending, soybean imports, and soybean imports from the United States on consumer spending in China. As can be seen from the figure, the impact of these three factors will cause certain volatility in consumer spending in a short period of time, after which the influence tends to be stable. In the same way, the line graph in Figure 5 also reflects that the impact of soybean imports from the United States will have a lasting effect on consumer spending. First of all, soybeans are used in many fields in China: food, breeding, medicine, industry, etc.
They have a wide range of uses and large amounts; China has a long history of soybean use and soybeans have a certain viscosity effect on Chinese consumers. Moreover, the large number of Chinese soybeans imported from the United States will certainly have a certain influence on the Chinese soybean market.

Outlook
Although this article analyzes the impact of imported soybean origin countries, it only analyzes the amount of money, and does not consider quantity and unit price factors. In addition, this article limits the research object of influence between the import amount and the resident consumer expenditure, but for different eras, the social price index, exchange rate, and consumption concept also have certain differences. All these are the deficiencies of this article. They are also the direction that the author and my colleagues can work hard in the future.