Research On Fluctuation And Forecast Of Potato Prices In China

Potato is the fourth largest food crop in China except rice,wheat and corn.Because it has many advantages,such as wide planting range,various uses and considerable economic benefits,it has become the first choice for farmers in poor areas to achieve the goal of increasing production and it plays an important role in ensuring national food security.In recent years,potato price has become more and more volatile,which has disturbed the normal operation of potato market,and has brought negative impact on potato industrial development.Therefore,it is of great significance to study the laws of potato price fluctuation,to explore the reasons of potato price fluctuation,and to use scientific methods to predict potato price,in order to stabilize potato production,protect the interests of potato producers,and promote the healthy development of potato industry.This article used the price of potato wholesale market in China from 2005 to 2019,and applied CensusX12 seasonal adjustment method and H-P filtering method to decompose the price of potato wholesale market;and the annual,quarterly and monthly fluctuation characteristics of potato wholesale market price were analyzed;and the short-term prediction of potato wholesale market price in the future was made by seasonal index prediction method;and the reason of fluctuation of potato wholesale market was explained.ARIMA model is one of methods of time series forecasting theory and GM(1,1)model is one of the most widely used methods of grey forecasting theory,they were used to fit and forecast the weekly price of potato wholesale market;the weight of single model was determined by the reciprocal method of mean square deviation,and then ARIMA(4,0,0)-GM(1,1)combined model was built,and this model was used for short-term forecasting of the potato wholesale market price in 2020.Finally,the forecasting accuracy of each model was measured and analyzed,according to the analysis and forecasting results in line with the characteristics of potato price fluctuations.In term of innovation,this paper analyzes the fluctuation rule of potato wholesale market price from three dimensions(year,quarter and month),and uses the gray prediction method and combination prediction method in the prediction of potato price.At the end of this article,some policy suggestions were put forward to stabilize the price forecasting and promote the development of potato industry.The main progress and conclusions were as follows:(1)In 2005-2019,the price of potato wholesale market in China showed a trend of gradually rising,and the intensity of annual fluctuation gradually increased.At the same time,it shows a three-year fluctuation cycle.From the perspective of quarterly fluctuation,the average price of potato wholesale market is the highest in the first quarter,followed by the second quarter,and the third and fourth quarters respectively.From the perspective of monthly fluctuation,the monthly average price of potato wholesale market mainly fluctuates in a small and medium range.On average,there is a small fluctuation in 1.81 months,a medium fluctuation in 2.62 months and a large fluctuation in 15.45 months.(2)It is considered that the seasonal characteristics of potato production,market uncertainty,consumption demand,external impact,market information asymmetry and other factors have a great impact on the price fluctuation of potato wholesale market.(3)The prediction accuracy of combined prediction model,ARIMA model and GM(1,1)m odel was from high to low.Combined prediction model fitting error is controlled within 10%.The impact of COVID-19 pandemic is gradually weakened after May 2020,and the potato who lesale market price will slowly decline.(4)The corresponding policy suggestions are put forward from the aspects of strengthening the research of potato price fluctuation,establishing data collection platform,standardizing the way of forecast information push and strengthening the personnel training.