| In 2008-2015,the Chinese government implemented the Temporary Purchase and Storage Policy of Corn(TPSPC)in the northeast region,which played a role in supporting the corn market and raised the market price of corn.Is the impact of the TPSPC only this?As one of the three main grains,corn has many downstream industries,and the changes in the corn industry have a greater impact on downstream industries.Take the corn-pig industry chain as an example,the cost of individual corn accounts for about 25.00%of the total cost of pig farming,so the corn industry and pig industry are more closely linked.The implementation of the TPSPC has caused the price of corn to rise.Further,will the increase in corn price be transmitted from the upstream to the downstream along the corn pig industry chain,thus forming an impact on pig price?From the perspective of corn-pig industry chain,this paper analyzes the impact of the TPSPC on the downstream pig industry,with two dimensions of time and space.The study of time dimension includes the impact of the TPSPC on the industrial chain and the time mechanism of the price transmission of the pig industry chain.The time mechanism of price transmission are divided into the path of price transmission and the magnitude of price transmission.First,identify the impact of the TPSPC along the industrial chain on pig prices.Different from the previous analysis using linear model,this paper uses the MSVAR model with nonlinear characteristics to identify the time when the TPSPC has a structural impact on the price of pigs,and avoids the randomness and bias of subjective division of policy time points.Thereby it is more objective and accurate.Specifically,before the implementation of the TPSPC,the pig industry was in a“stable state”.After the implementation of the TPSPC in 2008,the pig industry significantly deviated from its original“stable state”and entered the“down state”and“high state”.Second,the path of price transmission.The price transmission path of the pig industry chain ranges from the upstream corn price to the mid-stream pig price to the downstream pork price and finally to the general price level CPI.The corn-pig industry chain is linked by raw materials and indicators,and quantitative co-integration tests and Granger causality tests support the analysis of conduction paths.From the cointegration test,there is a threshold cointegration between corn price and pig price,and there is linear cointegration between pig price and pork price,pork price and CPI.Threshold cointegration indicates that the relationship between variables is non-linear,and linear cointegration indicates that the relationship between variables is linear.At the same time,Granger causality tests show that the upstream link is the Granger reason for the next link,along corn prices,pig prices,pork prices,and the CPI.Third,the magnitude of price transmission.During the different policy periods,the impact of the price transmission of the pig industry chain was significantly different.Compared with the implementation of the TPSPC,the impact of corn price on the price of pigs during the policy implementation period increased significantly.The short-term effect increased from 0.37%to 0.78%,and the cumulative effect increased from55.00%to 190.00%.At the same time,in the variance decomposition of the pig price forecast error,the contribution of corn price also increased from2.87%to 6.04%.Moreover,the price of pigs is equally affected by the pig market itself.From the variance decomposition of the prediction error of the pig price,the contribution of the pig price is about 35.00%before the policy is implemented or during the policy implementation period.The study of spatial dimension includes the impact of the TPSPC on the industrial chain and the spatial mechanism of the price transmission of the pig industry chain.The spatial mechanism of price transmission are divided into spatial regionality and spatial correlation of price transmission.First,analysis of the impact of the TPSPC on the price of live pigs in Northeast China Since the implementation of the TPSPC is in the northeastern region,the impact of this policy on the price of pigs in the Northeast is more prominent than in other provinces.The results show that the TPSPC has a significant positive effect on the price of live pigs in the Northeast.The implementation of the TPSPC has caused the price of pigs in the Northeast to rise by 4.24%,and the contribution rate of the policy accounted for 8.39%.If we consider the lag factor of pig breeding to the slaughter,the TPSPC has increased the price of pigs in the Northeast by6.76%,and the contribution rate of the TPSPC has increased to 27.35%.Moreover,the TPSPC has increased the price volatility of pigs in Northeast by 21.37%,and the policy contribution rate is 49.26%.In addition,the pig prices and the volatility of pig prices were significantly affected by the explanatory variables lag by about 5 months.Second,the spatial correlation of price transmission.Focus on the spatial circulation and trade of the pig market,thus forming the characteristics of spatial connection.The spatial econometric model was used to analyze the impact of TPSPC on pig prices at the national level.The spatial econometric model is more accurate than the basic panel model estimation,and the spatial weight matrix of the total production of the pig market is more effective.After the implementation of the TPSPC,the price elasticity of corn prices to pigs increased significantly by 40.88%.The main reason for the increase in price elasticity is that after the implementation of the TPSPC,the market power of the pig industry has declined.The market power of the corn industry has risen,and the bargaining power of the pig industry has decreased.The bargaining power of the corn industry has increased.This has caused an increase in the impact of corn prices on pig prices.Third,the spatial regionality of price transmission.Focus on the spatial distribution of corn prices in neighboring provinces,and analyzing the impact of the TPSPC on the price elasticity of corn-pigs in different regions.From the perspective of regional division,the spatial distribution according to corn price can be divided into five regions.The distance from each region to the implementation of the TPSPC is from near to far.The corn price advantage before the TPSPC is gradually reduced from near to far.The intersection of the corn price and the regional dummy variable is added to the panel model,and the two-way fixed effect is used for estimation.The results showed that,where the price advantage of corn is greater,the corn-pig price elasticity is more affected by the TPSPC.Therefore,both the time dimension and the spatial dimension,the upstream TPSPC has had a significant impact on the downstream pig price.The policy implications of this paper are as follows:(1)The formulation of relevant agricultural policies should be based on the industrial chain.The impact of upstream policies on downstream industries cannot be ignored,especially upstream products account for a large proportion of downstream production costs.(2)The understanding of the development of agricultural industry should have a staged thinking,and relevant agricultural policies need to be adjusted in a timely manner to meet the development needs of the agricultural industry in the new stage.(3)The development of various industries in the agricultural sector should be planned from a national perspective,and the comparative advantages of local pig breeding should be brought to optimize the distribution of pig production capacity nationwide.The innovations in this paper include three aspects.First of all,industry chain perspective.From the perspective of the corn-pig industry chain,analyze the impact of the TPSPC on the downstream pig industry.This study makes up for the existing price transmission research,which focus only on the partial links.In the past,most of the research was limited to the level of a single industry.No industrial chain thinking has been formed.Talking about the development of pig industry in terms of pig industry policy.The corn-pig industry chain is closely linked and contradictory.In order to maintain the stability of upstream corn production and prices,the TPSPC has had an impact on the downstream pig industry.Therefore,this requires analysis from the corn-pig industry chain perspective to capture the key issues in the development of the pig industry.Secondly,multidimensional analysis framework.It analyzes the price transmission mechanism of the corn-pig industry chain from time and space.Most of the existing literature on the price transmission of the pig industry chain is only analyzed from the time dimension.According to the three basic elements of the corn storage policy,the paper analyzes the price transmission mechanism of the corn-pig industry chain from the two dimensions of time and space,namely time mechanism and spatial mechanism.The time mechanism of price transmission are divided into the path of price transmission and the magnitude of price transmission.The spatial mechanism of price transmission are divided into spatial regionality and spatial correlation of price transmission.Secondly,multidimensional analysis framework.It analyzes the price transmission mechanism of the corn-pig industry chain from time and space.Most of the existing literature on the price transmission of the pig industry chain is only analyzed from the time dimension.According to the three basic elements of the corn storage policy,the paper analyzes the price transmission mechanism of the corn-pig industry chain from the two dimensions of time and space,namely time mechanism and spatial mechanism.The time mechanism of price transmission are divided into the path of price transmission and the magnitude of price transmission.The spatial mechanism of price transmission are divided into spatial regionality and spatial correlation of price transmission.Third,the spatial weight matrix of the pig market.Due to the spatial correlation of pig prices,in order to more accurately reflect the spatial connection of the pig industry,a spatial weight matrix(W~2)for total pig production is constructed,abandoning the traditional spatial weight matrix only contains the spatial distance.The spatial correlation coefficient was well significant when using W~2,which was significant at 5%in 2001-2007and significant at 1%in 2008-2015.The construction of W~2 provides support for the analysis of spatial mechanism of pig price transmission. |
