Analysis On Temporal And Spatial Variation Trend And Influencing Factors Of Pork Price

Pork prices change radically in recent years.Especially since 2019,pork prices have been greatly affected by African swine fever and COVID-19.This has brought great risks to farmers.As pork is an important commodity in the preparation of consumer price level,the dramatic changes in pork prices will also have a certain impact on the economic and social sectors.Due to the regional differences in pig breeding in China,there are also some differences in pork prices around the country,which has a certain impact on the regional economic development.The spatial and temporal differences in pork prices not only affect people’s daily consumption,but also affect the regional economic development.To understand the characteristics of pork prices,we need to make a comprehensive study from the perspectives of time and space.The study of pork price from the perspective of time mainly studies the periodic fluctuation characteristics of pork price.Traditional filtering methods generally need to provide an empirical parameter when decomposing time series,and the filtering effect will be very different with different parameters.In order to solve the subjectivity of parameter setting of traditional filtering methods,the periodic decomposition method is improved and innovated,and the objective information carrying capacity is added to the standard of periodic decomposition with different steps.Through the multi-stage periodic decomposition of pork price by using the improved method,the data adopts the daily quotation of pork price in Jiangsu Province from January 1,2014 to December 31,2021.After the multi-stage decomposition of pork price cycle,four different types of cycles are finally obtained,namely long cycle,medium cycle,short cycle and micro cycle.The average time span of the long-term cycle is 53 months,about 4 years,which is consistent with previous relevant studies.The long-term cycle is mainly affected by long-term supply factors and is related to the pig stock,which is the main factor affecting the pork supply in the market.The average length of the medium cycle is 323 days,which is close to one year.The medium cycle is mainly reflected in quarterly factors,especially the quarterly characteristics of the year.From the perspective of the medium cycle,there will be a complete cycle every year.Most of the peaks of the medium cycle will appear in the second half of the year and very few in the first half of the year.The medium cycle is related to seasonal climate,which mainly reflects the factors of pork market demand.The third cycle is short cycle.The average time span of short cycle is 149 days,about half a year.The short cycle mainly reflects the impact of emergencies or contingencies.The short cycle does not have much regularity,which is mainly reflected in the short-term changes in market demand caused by contingencies.The micro cycle mainly reflects the impact of random fluctuations on pork prices,which is relatively close to random changes.Using tabulate 2019 software,the descriptive statistical indicators of pork prices in all provinces are compared and analyzed in space.It is found that the average value of pork prices in central provinces is relatively low,the distribution of pork prices across the country presents a basin shape,and the pork prices in coastal and southern provinces are higher than those in central provinces.The standard deviation and coefficient of variation of pork price are used to reflect the stability of pork price in different provinces.Through comparison,it is found that both the standard deviation of absolute indicators and the coefficient of variation of relative indicators in central provinces show the characteristics of lower in central provinces and higher in South and coastal areas,and also show a basin structure.Then,through the correlation analysis of pork prices in various provinces,it is found that the correlation of pork prices in various provinces is high.Then,the characteristics of this correlation are further studied from a dynamic perspective.Using the Va R variance decomposition method,the mutual interpretation ability between different provinces is counted in the matrix table,and the accumulation effect and accumulation contribution between them are calculated.The study found that pork prices have multi-stage periodic characteristics,and there is an interactive relationship between these multi-stage cycles.The long cycle will have an impact on the shorter cycle.From a spatial perspective,pork prices have obvious spatial distribution characteristics.Pig producing areas are mainly distributed in central provinces and cities,and spread from the central to the periphery.Through the study of the temporal and spatial characteristics of pork price changes,It provides a basis for exploring the reasons affecting the change of pork price,and provides a theoretical reference for the government to formulate reasonable industrial policies.