Abstract Vegetables, as one of the most important non-staple foods in the daily consumption of Chinese residents, are closely related to the life of urban residents. The fluctuation of regional vegetable prices has a negative effect on producers and consumers. Relevant research on vegetable price fluctuations has been carried out, which provides a corresponding basis for realizing the balance of supply and demand in the agricultural products market within Guangxi, and for government departments to macro-regulate agricultural production and optimize the agricultural industrial structure.
　　Key words Guangxi; Vegetables; Impact; Price fluctuation; Cycle
　　Received: March 25, 2020Accepted: May 7, 2020
　　Haiyan GAN (1964-), female, P. R. China, senior editor, devoted to research about agricultural economic ecology.
　　*Corresponding author. E-mail: haiyan68098@163.com.
　　Vegetables, as one of the most important non-staple foods in the daily consumption of Chinese residents, are closely related to the lives of urban residents. Frequent increases in vegetable market prices will directly affect the quality of life of residents and bury hidden dangers for the plunge of vegetable prices in the next round of prices, while the continued decline in vegetable prices causes the prices to be too low and pose a negative influence on the vital interests and production enthusiasm of vegetable farmers, which makes the supply of vegetables not well-protected and causes next round of skyrocketing price easily. Fluctuations in regional vegetable prices have a large negative effect on producers and consumers, which in turn affects the stable operation of the macroeconomics and seriously reduces the level of regional social welfare. Therefore, relevant research on the fluctuations of vegetable prices can facilitate the understanding of changes in the supply and demand of agricultural products on the market, and help to correctly guide the rational arrangement of agricultural production and improve the efficiency of agricultural products circulation, so as to achieve the balance of supply and demand in the agricultural products market within a region and provide corresponding basis for government departments to macro-control agricultural production and optimize agricultural industrial structure.
　　In this study, with the vegetable wholesale markets of 14 prefecture-level cities in such five regions as eastern Guangxi (Yulin, Guigang, Wuzhou), western Guangxi (Hechi, Baise, Chongzuo), southern Guangxi (Nanning, Beihai, Qinzhou, Fangchenggang), northern Guangxi (Guilin, Hezhou) and central Guangxi (Liuzhou, Laibin ) as representatives of the Guangxi vegetable wholesale market, several of the most common and representative vegetables in the agricultural product market were selected as research objects to discuss the basic situation of Guangxi vegetable price fluctuations and features. The vegetables selected mainly included annual Chinese cabbage, fruit and vegetable type tomato (tolerant to storage), green pepper (not tolerant to storage), storage-tolerant potatoes and fresh water spinach. The data used was acquired from the Guangxi Agricultural Products Supply and Demand Information Network (promulgated by the Agricultural Products Price Information Center of the Guangxi Agricultural Department) and the Guangxi Agricultural Information Network. The time span is February 2009 to April 2014. 　　Time Characteristics in Price Fluctuations of Different Types of Vegetables
　　Periodicity of vegetable price fluctuations
　　Vegetable prices had obvious cyclical fluctuations over the years
　　As can be seen from Fig. 1-Fig. 5, from February 2009 to April 2014, the prices of the same vegetable had obvious cyclical fluctuations over the years, but the price fluctuations of different types of products showed different laws.
　　Chinese cabbage
　　As an annual vegetable, Chinese cabbage is the most common vegetable in the vegetable market. It can be seen from Fig. 1 that the market price of Chinese cabbage fluctuated more regularly over the years, and basically had an "M" distribution for each year. The annual peaks occurred in March and November each year, and the price was mostly in the trough period from June to August. A complete cycle of cabbage price fluctuations generally lasted for 3-4 months, and the frequency of fluctuations was relatively large. For a specific year, the fluctuations were slightly different. Although Chinese cabbage is an annual vegetable, the strong nature of its substitutes determines that the price of Chinese cabbage will fluctuate to a certain extent along with the price fluctuations of other vegetables, resulting in large market price fluctuations of Chinese cabbage.
　　Tomato
　　Tomatoes are a kind of storage-resistant vegetable and fruit. Fig. 2 shows the price fluctuations of tomatoes. The fluctuations in tomato price were not very cyclical, and the price was basically stabilized during a year. After 2012, the price fluctuated more frequently, but the overall performance was relatively stable over the years. A complete cycle of tomato market price fluctuations generally took 3-5 months. The main reason is that tomatoes are kind of storage-tolerant vegetable and fruit produced in the south, which has relatively stable output, and the market price fluctuation frequency is relatively stable.
　　Green pepper
　　Green peppers are a kind of intolerant vegetable and fruit. The price fluctuation of green peppers was similar to that of tomatoes. It can be seen from Fig. 3 that the price of tomatoes was basically a straight line and did not changed much before 2012. After 2012, the price rose and fluctuated to a certain extent, but in general it looked basically stable within a cycle (one year). Unlike tomatoes, a complete cycle of green peppers  market price could be as short as 2 months and as long as 8 months. The reason is that green peppers are a kind of vegetable not tolerant to storage, and their price is obviously affected by climate and season. 　　Potato
　　As a storage-tolerant vegetable, the market price of potato was quite different from those of storage-intolerant vegetables. As shown in Fig. 4, the fluctuations in the price of the potato market were not obvious, and it kept fluctuating at a certain price level over the years, within a small range.
　　Water spinach
　　Water spinach is a typical seasonal vegetable with strong seasonality. It can be seen from Fig. 5 that the price of water spinach market fluctuated violently, showing a "W" distribution within one year. The peak price period occurred in February and October, and the price trough occurred in June and September. The price is obviously affected by climate and production season.
　　The Main Reason for the Fluctuation of Vegetable Prices in Guangxi
　　The production of agricultural products has its particularity and is greatly affected by natural factors, especially vegetables with a short production cycle, of which the growth process is affected by natural factors such as temperature, humidity, water and heat. The production of different varieties of vegetables has a strong seasonally, and their yields show strong seasonal fluctuations. Vegetables, like other agricultural products, are affected by factors such as asymmetry in market information and the existence of cyclical production. Vegetable production itself has a lag, which can easily lead to fluctuations in production and supply, and ultimately lead to a new round of vegetable price fluctuations. In addition, the circulation of vegetables in the market has high requirements for storage and transportation, which constitute an important part of the production cost of vegetables. Vegetable circulation has always been a relatively weak link for Guangxi, and it is particularly vulnerable to emergencies. The combination of various factors will cause extraordinary fluctuations in vegetable prices. On the other hand, it is also necessary to consider the impact of government macro-control on vegetable prices. The government s macro-control of the vegetable market generally uses subsidies and other price means. Usually, when the vegetable price is high, the government gives vegetable producers and operators corresponding subsidies to stabilize the vegetable market price. Its essence is to promote the development of the vegetable industry and increase the supply of vegetables, finally reducing market prices. However, any price adjustment measures and administrative policies have inertial effects. If not properly controlled, it will easily cause the supply of vegetables to exceed market demand and prices to fall sharply. In addition to factors affected by human regulation, vegetable prices are also affected by unpredictable and uncontrollable natural factors. For example, the impact of vegetable disaster area on vegetable output and vegetable prices is obvious. In 2008, after the disaster of low-temperature freezing rain in Guangxi, the prices of vegetables soared. In addition to affecting the price of vegetables by affecting the supply of vegetables, the area affected by vegetables also provides a large amount of idle funds for speculation in the society, which further amplifies the impact of vegetable disasters on vegetable prices, which in turn affects vegetable price fluctuations. These factors are the main factors affecting the price fluctuations in the vegetable market. 　　Relative to the normal fluctuations in vegetable prices, Guangxi vegetable prices fluctuate more frequently and fluctuate widely. This is closely related to the production and circulation of regional vegetables. The main reasons for the fluctuations in Guangxi vegetable market are:
　　From the perspective of vegetable production, vegetable production is relatively small and the output is unstable
　　The characteristic of vegetable production and planting in most areas of China is that the production is carried out by households which are scattered and operates separately, the production scale is mostly small, and Guangxi is no exception. The small-scale and decentralized production model allows farmers to judge the market based on previous production experience, and it is difficult to effectively plan vegetable cultivation, which can easily cause vegetable cultivation not to be closely integrated with market demand. Due to the problem of information asymmetry between the market and the farmers, vegetable growers have difficulties in grasping accurate market information, lack reference and guidance, and can only make vegetable cultivation decisions based on the vegetable prices of the previous period, resulting in very unstable production of a single variety of vegetable. It is easy to appear that a large number of vegetables are concentrated on the market or that the same kind of vegetable is scarce in a certain period of time, resulting in large fluctuations in the supply of the vegetable market, resulting in large fluctuations in market prices.
　　Vegetable cultivation needs certain conditions. Due to the influence of natural conditions, vegetable production is seasonal and regional. Generally speaking, when the weather conditions are suitable, when the local vegetables are put on the market in large quantities, the price will drop sharply, and because the production season of the vegetables does not correspond to the consumption, the vegetables will appear "spring off-season" and "autumn off-season" every year. In these two seasons, due to the temporary shortage in vegetable production, generally, the local vegetables are scarce, and most of the vegetables on the market are from other places, and there is often a rapid increase in vegetable prices. After the "off-season", as local vegetables are listed, vegetables from other areas will suffer a decrease in price, and even be forced to withdraw from the local market.
　　On the other hand, the instability of the prices of means of production affects the fluctuation of vegetable prices. The transaction prices of oil and other bulk commodities in the international market rises sharply, which leads to an increase in the cost of means of production in China, which drives up prices. Since 2007, the implementation of the linkage mechanism between oil prices in China and oil prices in the international market has led to continuous changes in the cost of production materials in China, affecting the changes in vegetable production inputs and directly affecting the output and market supply of vegetables in different periods or inter-annual years. According to reports, the total consumer price level (CPI) of residents in Guangxi increased by 3.8% in 2012. Specifically, the prices of agricultural production materials rose by 8.0%, the prices of chemical fertilizers rose by 7.6%, and the prices of agricultural production services rose by 5.4%. Affected by the above price changes, the price of vegetables rose by 17.6%. 　　In addition, Guangxi s vegetable production is less organized, making it difficult to connect scattered farmers with large markets. The scope of the farmer households covered by the existing professional vegetable cooperative organizations is very limited, and the functions of the cooperative organizations are not played well. The enthusiasm of farmers is not high, and it is difficult to well protect farmers  production sales and sales market prices.
　　From the perspective of vegetable processing, vegetable industrialization is low
　　Due to the low degree of development of vegetable industrialization, the disconnection of the pre-production, mid-production and post-production of the vegetable production industrial chain severely limits the effective utilization and sustainable development of vegetable resources, making it difficult for the vegetable industry to form a development situation of the integration of agriculture, industry, commerce, production, supply and marketing. At present , there are fewer leading enterprises engaged in vegetable production and processing in Guangxi, and the number of farmers is also limited. The production scale of enterprises is relatively small. The production technologies used are relatively backward. The equipment level is low. Enterprise production generally lacks high-quality and high-level monitoring methods, and some high-tech technologies such as biotechnology have not yet been promoted and applied. In terms of enterprise management, the vegetable processing industry lacks standardized, scientific and modern management, lacks industrialized groups, and has poor brand awareness.
　　From the perspective of vegetable circulation, the circulation channels are not smooth and the function of the wholesale market is not perfect
　　At present, there are many kinds of vegetable circulation channels in the vegetable market, generally divided into several types. One is to directly flow into the local farmers  market at the place of production. This type of circulation channel is shorter and the circulation efficiency is the highest. The second is to flow from the place of production to the place of sale. This type of circulation has many links and long channels. The third is to flow into retail links through various wholesale markets. For this type, some of the materials flow into the retail sector through the first-level wholesale market, and some enter the retail sector through two or more levels of wholesale markets. This intricate circulation link makes the circulation cost of vegetables increase sharply, resulting in unstable vegetable prices. The profit pressure of the circulation links and the various drawbacks of the current agricultural products circulation system have led to the emergence of two very different phenomena: "the low price of vegetables hurts farmers" at the beginning of agricultural products circulation and "the high price of vegetables hurts farmers" at the end consumer market of agricultural products. The rising trend of vegetable prices not only does not increase the income of vegetable farmers, but also makes consumers a bearer of high costs, which not only damages the enthusiasm of vegetable farmers, but also reduces the social welfare level of urban residents. 　　On the other hand, the Guangxi vegetable market generally lacks a relatively complete vegetable price formation mechanism. The vegetable wholesale market is too fragmented due to the fact that the business and demand entities are too scattered. The development market s operation criteria are not perfect, the market access mechanism is not perfect, and the management order is not clear. These negative factors are not conducive to the formation of a long-term relatively stable vegetable market price.
　　From the perspective of benefit distribution, the benefit distribution mechanism is unreasonable
　　Profit distribution is the core link in the entire vegetable industry chain and the link that connects the various participants in the industry chain. In the initial link of the industry chain, there are a large number of scattered vegetable farmers. For vegetable farmers, although the production cost of vegetables is one of the important contents of vegetable prices, but for many reasons, vegetable farmers do not have the right to speak for bargaining, nor the ability to participate in the distribution of circulation benefits. Vegetable farmers are in a weak position in the distribution of benefits from rising vegetable prices. Therefore, in the real environment of rising commodity prices and soaring vegetable prices, vegetable farmers must bear the pressure of rising production costs on the one hand, and on the other hand, the purchaser who is a strong monopoly buyer will also pass on some of the rising costs in the circulation link to vegetable farmers by lowering the purchase price of vegetables, which further leads to a decline in the profitability of vegetable farmers  cultivation. The essence is that the vegetable farmers not only share part of the rising production costs, but also part of the rising circulation costs in the circulation link, so vegetable farmers suffer greater impairment of benefit in the distribution of benefits. For wholesalers, wholesalers bear the cost of purchase and sale in the production and marketing of vegetables, and due to the fact that there are often great changes in the costs of circulation and sales, wholesalers also face greater cost pressures and their benefits are not well protected.
　　Meteorological disasters and food safety incidents occur frequently, and the fluctuation intensity of vegetable price is intensified
　　In recent years, various natural disasters and meteorological disasters have occurred frequently, which has caused serious impacts on the production of vegetable industry. For example, the rain and snow disaster in Guangxi in 2008 caused a significant decrease in the supply of vegetables on the vegetable market in Guangxi , and the overall price rose and continued for a long period. On the other hand, recent food safety problems in China have occurred frequently. Many food safety incidents have triggered a crisis of public trust, which has led to an imbalance in market supply and demand and exacerbated price fluctuations in the vegetable market. 　　Policy Suggestions to Deal with the Fluctuation of Vegetable Prices in Guangxi
　　Improve the professional, large-scale and organized production levels of vegetable growers to ensure output
　　The thousands of scattered vegetable farmers are the main body of the vegetable production department. The production and management decisions of vegetable farmers directly affect the supply of the vegetable market. In view of the current situation of scattered and small-scale vegetable farmers in Guangxi, the degree of organization should be further strengthened, and farmers should be gradually guided to organize and professionalize production. It is necessary to guide and support a number of vegetable production family farms and farmers  professional cooperatives by region to improve the base production and large-scale production of vegetables, and to organize scattered vegetable growers to avoid market risks. The professional production level of vegetable growers should be improved, so that they can collect agricultural product market demand information, effectively organize production, uniformly plan the variety pattern, improve specialized production efficiency, and avoid blind selection of vegetable cultivation varieties. With professional cooperation organizations as the platform, we can actively create regionalized, specialized, specialized and branded vegetable production, stabilize vegetable production while improving market competitiveness, and safeguard vegetable farmers  vital interests. Meanwhile, the vegetable industry development layout plan that has been formulated in Guangxi should be refined to clarify the development direction, market direction or positioning, specific layout, planting structure (intra-seasonal structure, inter-seasonal structure), variety arrangement, etc.
　　Regulate the circulation of vegetables and improve the functions of the wholesale market
　　The vegetable circulation link is a link that links vegetable production and sales and effectively connects the supply and marketing between the producing area and the producing area and between the producing area and the selling area, and is an important link in the vegetable industry. In this link, whether the circulation is smooth determines the efficiency of market circulation. Therefore, we should further reduce the cost of circulation, closely link the market of vegetable production and the market of sale, establish a perfect market information platform, improve circulation means and technology, and exempt vegetable circulation link VAT, etc. , in order to effectively unblock the circulation link and improve market circulation efficiency. In addition to unblocking circulation, building a fully functional vegetable wholesale market is equally important. The vegetable wholesale market is an important organizational form of vegetable industrialization and plays a major role in the agricultural product market. Therefore, we should promote the scale and standardized development of the main body of the vegetable market, establish a strict vegetable wholesale market access mechanism, strengthen the wholesale market legal system, and strictly ensure the safety of vegetable products. In the exploration of market organization forms, we should actively construct "linking farmers and supermarkets" experiment units, build the "vegetable basket" project, support parity vegetable outlets, innovate market organization forms, and constantly improve the functions of the wholesale market. 　　Coordinate the vegetable production patterns in various regions and stabilize vegetable supply capacity in various regions
　　There is a close relationship between the price fluctuation trends of various vegetables in the vegetable market. Therefore, when a certain type of vegetable has abnormal fluctuations, the government should focus on macro-control, not just on the regulation of the certain type of vegetable. The means of regulation and control should be diversified, not limited to price means, such as the establishment of a scientific and reasonable agricultural product price formation mechanism, the formulation of a sound agricultural product price protection policy, and the establishment of a stable agricultural product circulation market, etc. , so as to effectively protect the basic interests of vegetable farmers and urban residents. From the perspective of the production pattern of vegetables, for agricultural products with large regional price differences and large differences in market supply, the government should actively guide and adjust, and use a combination of centralized and decentralized regulation to promote the normal circulation of agricultural products with large regional price differences.
　　Establish and improve the price regulation fund system to ensure stable market prices
　　The price regulation fund system is that the government raises certain fund through a certain channel, which is used for stabilizing market prices. A price regulation fund system should be established when the vegetable market price fluctuates abnormally, and used actively to support the production, circulation, storage and transportation of vegetables to prevent product prices from rising and falling. In general, the proportion of the price regulation fund used to support the production and circulation of vegetables should not be less than 30% of the total fund. On the other hand, in the face of abnormal fluctuations in the price of the vegetable market, the government should not only actively dispatch, allocate and organize and implement the supply of local agricultural and sideline products to prevent abnormal fluctuations in prices, but also severely crack down on illegal activities such as hoarding and raising prices to maintain normal market order and ensure stable vegetable market prices.
　　Increase investment to build a modern agricultural infrastructure, information platform and market system
　　Studies have shown that the prices of vegetables that are intolerant to storage fluctuate significantly, and the price risks faced by producers and operators of agricultural products are correspondingly large. Eventually, vegetable farmers are reluctant to take the risk and give up growing such vegetables, resulting in unstable total vegetable output and large price fluctuations. Therefore, responding to market risks is an important aspect of stabilizing vegetable market prices. From the government level, it is necessary to increase capital investment to build a modern agricultural product infrastructure and improve the matching of agricultural product processing and storage insurance facilities, so as to ensure a stable supply of vegetables intolerant to storage and effectively reduce the price changes of vegetables intolerant to storage. On the other hand, the government and local markets should also undertake to do a good job in forecasting market supply and demand and prices, establish an information platform for the promotion of agricultural product markets, accelerate the establishment of an information-integrated agricultural product market, and ensure that vegetable producers and operators participate in market activities to further reduces market risk. This also requires the implementation of agricultural product production and marketing information network construction projects and the establishment of fast and efficient vegetable production and marketing information channels, to eliminate the information barriers between producers and consumers, the origin and market, and the production and marketing of vegetables within and outside the region. In addition, the layout of vegetable wholesale markets should be optimized, the construction of the market system should be improved, and the establishment of a vegetable production and marketing market system with a reasonable layout and complementary functions of vegetable production areas and wholesale markets, and wholesale markets and sales areas, should be accelerated. 　　References
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　　Editor: Yingzhi GUANGProofreader: Xinxiu ZHU