Method for calculating price index of Shaanxi coal

Abstract

The invention relates to a Shaanxi coal price index calculation method, which comprises the following steps of 1, formulating a data acquisition principle, and acquiring data; step 2, screening the collected data; step 3, converting the collected data; step 4, calculating a price index; the Shaanxi coal price index calculation method reflects the real situation of the change of the Shaanxi coal market, is basically consistent with the trend and amplitude of the actual price change of the coal market in China, and has the indication effects of a wind indicator and a thermometer reflecting the change of the Shaanxi coal market.

Description

Technical Field

[0001] The invention belongs to the technical field of coal price index calculation, and in particular relates to a method for calculating Shaanxi coal price index. Background Art

[0002] Currently, the coal price indices with great influence in my country include the Bohai Rim Thermal Coal Price Index, the Taiyuan Coal Trading Price Index, and the Inner Mongolia Coal Price Series Index.

[0003] Bohai Rim Thermal Coal Price Index (BSPI in Chinese) is a general term for the index system that reflects the offshore closing price level and fluctuation of thermal coal in ports around Bohai Sea. The price system includes the comprehensive average price of 5500 kcal thermal coal representative specifications in the Bohai Rim region and the price range of representative specifications in each port. Bohai Rim Thermal Coal Price Index discovers prices by regularly collecting coal trading information and tracking thermal coal price changes in real time. It reflects the mainstream market price by using appropriate mathematical models and analyzes prices by describing the trend and law of thermal coal price changes. Bohai Rim Thermal Coal Price Index will form a domestic thermal coal price reference system with objectivity, timeliness, stability and representativeness, which will serve as a decision-making basis for coal supply and demand enterprises to participate in trading activities and as a reference indicator for the government to understand the coal market and conduct macro-control. Bohai Rim Thermal Coal Price Index consists of 1 comprehensive price and 24 representative specifications. 1 Comprehensive price refers to the comprehensive weighted average price of 5500 kcal thermal coal in the six representative ports around Bohai Sea (Qinhuangdao Port, Caofeidian Port, Tianjin Port, Jingtang Port, SDIC Jingtang Port, Huanghua Port). 24 Specifications Prices refer to the reference price ranges of the four representative specifications of thermal coal of 4500, 5000, 5500 and 5800 kcal corresponding to the six representative ports. The comprehensive price is a quantitative indicator reflecting the overall level of 5500 kcal thermal coal prices in the Bohai Sea Rim region, which is obtained by weighted average of the average price of 5500 kcal thermal coal in each representative port according to the coal throughput weight of the port. The price range of representative specifications of representative ports reflects the actual transaction price level of thermal coal of each representative specification of the representative port, which is calculated by specific rules based on the actual offshore closing price of each representative specification of the port and the corresponding weights.

[0004] The Inner Mongolia coal price series index has now formed a coal price index system covering the entire region with Ordos coal, eastern Inner Mongolia lignite, and western coking coal. Through the compilation of the price index, the mainstream market price of coal in the production area has been discovered, a scientific coal pricing mechanism has been formed, and the voice of coal in the main production area of ​​Inner Mongolia in coal trade has been enhanced, providing a scientific price reference for coal production, transportation and sales customers. Among them, the Ordos coal price index system includes mixed coal price index and lump coal price index. The mixed coal price index comprehensively reflects the price level and fluctuation of Ordos mixed coal; the lump coal price index comprehensively reflects the price level and fluctuation of Ordos lump coal. The Ordos mixed coal price index consists of 1 comprehensive index and 6 pithead price specifications and 5 car plate price specifications. The Ordos lump coal price index consists of 1 comprehensive index and 4 pithead price specifications. The lignite price index in eastern Inner Mongolia is a general term for the price and index system that comprehensively reflects the supply and demand relationship and price level change trend of lignite shipped by train from shipping stations (logistics parks) and pits in eastern Inner Mongolia with railway transportation as the node. The coking coal price index in western Inner Mongolia is a general term for the price and index system that comprehensively reflects the supply and demand relationship and price level change trend of washed coal in western Inner Mongolia with coal washing plants as the node.

[0005] The Taiyuan Coal Trading Price Index (CTPI-2.0) (Railway) is an upgraded and optimized version of the predecessor of the China Taiyuan Coal Trading Price Index (CTPI). On May 23, 2013, China's first major coal trading price index, the China Taiyuan Coal Trading Price Index (CTPI), was jointly released by the China (Taiyuan) Coal Trading Center and Xinhua News Agency China Economic and Social News Holding Co., Ltd. On July 19, 2016, the upgraded and optimized China Taiyuan Coal Trading Price Index System (CTPI-2.0) was officially released to the public. The China Taiyuan Coal Trading Price Index (CTPI-2.0) (Railway) consists of four parts: the first part is the comprehensive price index; the second part is the classified trading price index; the third part is the weighted average price of representative specification products; and the fourth part is the price of single-point products. (1) Comprehensive price index. It comprehensively reflects the trend and rise and fall of the trading price of coal production areas in Shanxi Province. The index is composed of the comprehensive weighted average price of the four categories of trading prices: thermal coal, coking clean coal, pulverized coal injection clean coal, and chemical raw coal. The sample point price type is the car plate tax-inclusive price. (2) Classification price index. The classification transaction price index consists of four categories and five subcategories. Four categories: China Taiyuan thermal coal transaction price index, China Taiyuan coking clean coal transaction price index, China Taiyuan pulverized coal injection clean coal transaction price index, China Taiyuan chemical raw coal transaction price index. Five subcategories: China Taiyuan thermal coal transaction price index is subdivided into two subcategories: China Taiyuan water-based thermal coal transaction price index and China Taiyuan direct thermal coal transaction price index; China Taiyuan coking clean coal transaction price index is subdivided into three subcategories: China Taiyuan coking coal transaction price index, China Taiyuan fat coal transaction price index, and China Taiyuan lean coal and lean coal transaction price index. (3) Weighted average transaction price of representative specification products. 17 representative specification products with specific quality indicators, strong operability, guiding prices, and closer to actual transaction contracts are set. The weighted average transaction price of representative specification products is the weighted average transaction price of each sampling point in the current period. (4) Single-point variety price. Single-point variety price reflects the price of specific coal varieties in each region. The price setting of single-point varieties takes into account different shipping areas, and selects varieties with large shipping volumes, stable quality indicators, certain influence in the market, representative regions and mining points in each region, so that regional prices can serve as a reference.

[0006] At present, the Bohai Rim thermal coal price index is based on the Bohai Rim ports and faces the economically developed eastern regions. It mainly reflects the coal supply and demand relationship between the northern channel collection and transportation centers for coal export from the "Three Wests" and the eastern coastal areas and riverside areas. It cannot reflect changes in factors such as the supply and demand situation of railway power in the central China market, Sichuan and Chongqing market and neighboring areas.

[0007] There is a reasonable gap between the price levels reflected by the Inner Mongolia Coal Price Series Index and the Taiyuan Coal Price Index and the Bohai Rim Coal Prices, but overall, the linkage between the Ordos Coal Price Index and the Bohai Rim Price Index is strong, and there is a large gap between the main varieties established by the Taiyuan Coal Price Index and the Shaanxi coal varieties.

[0008] The above three indexes have obvious regional limitations, while the factors affecting the price of Shaanxi coal are complex and the price trend is relatively unique. The coal in Shaanxi Province is seriously restricted by the bottleneck of railway transportation. A large amount of coal is directly transported to the consumption place by car, or transported by car to the railway collection and transportation stations in Shanxi, northern Shaanxi, western Inner Mongolia and other places, and then loaded on trains for transportation. In the future, with the expansion of the Shenshuohuang Railway, the commissioning of the Jinzhongnan Railway and the Zhangcao Railway, more coal in northern Shaanxi will be transported by car to the collection and transportation lines of the above railways for transit and transportation. In addition, with the expansion and commissioning of the Xikang Railway, Xining Railway and Menghua Railway, Shaanxi's coal sales to central China, Sichuan and Chongqing will grow relatively fast. The coal demand in these regions is highly seasonal and is greatly affected by air conditioning load and hydropower output. Therefore, the supply and demand situation and price trend of Shaanxi coal not only depend on the fundamentals of national coal supply and demand, but also on the supply and demand situation of railway transportation capacity in neighboring areas, changes in automobile freight, air conditioning load, hydropower output and other factors, which make it have relatively independent personalized characteristics, and the price trend of coal markets in Shanxi, western Inner Mongolia and other places, especially the Bohai Rim market, is often different. Summary of the invention

[0009] In order to solve the problem of lack of calculation method for Shaanxi coal price index.

[0010] A method for calculating the Shaanxi coal price index described in the present invention comprises the following steps:

[0011] Step 1: Establish data collection principles and collect data;

[0012] Step 2: Screen the collected data;

[0013] Step 3: Convert the collected data;

[0014] Step 4: Calculate the price index.

[0015] Furthermore, the step 1, formulating data collection principles, and the specific process of collecting data includes:

[0016] Step 101: Divide the market area. The principle of dividing the regional market is:

[0017] (1) In adjacent, interconnected regions, the price gap within the region is smaller than the price gap between the region and its neighboring regions;

[0018] (2) Having the same or similar production and consumption characteristics, import and export characteristics, transportation routes and modes, and similar circulation patterns;

[0019] (3) The determining factors of market fluctuations are the same or similar;

[0020] Step 102: Divide the market into categories. The principles for dividing the market categories are:

[0021] A. They can be used as substitutes for each other in the market; first, they have the same or similar uses and user groups, and can be divided into coking coal, thermal coal, and anthracite; second, they have the same or similar quality, and can be divided into coking coal and coking coal, and thermal coal can be divided into several varieties according to different qualities;

[0022] B. Have considerable spot trading volume;

[0023] Step 103, classify the transportation modes, and classify the transportation modes of Shaanxi coal into two modes: road transportation and railway transportation;

[0024] Step 104, according to the principle of dividing the market units into transport modes, market areas, and market varieties, determine the specifications and varieties and the comprehensive index;

[0025] Step 105: Set the price collection points, determine the collection samples, and form a coal information collection network;

[0026] Step 106: Determine the price collection period and base period, and complete data collection.

[0027] Furthermore, in step 2, the collected data is screened using the confidence interval method, and the calculation formula is as follows:

[0028]

[0029] in, represents the sample mean within the original data interval, s represents the sample standard deviation, and p min is the lower limit of the interval, p max is the upper limit of the interval, p i is the i-th sample price in the sample space.

[0030] Furthermore, in step 2, the collected data is screened using the median method, and the calculation formula is as follows:

[0031]

[0032] Among them, P is the sample space (ordered), N is the sample size in the sample space, and d ratio is the removal ratio, num is the number of removals, p min is the lower limit of the interval, p maxis the upper limit of the interval, p i is the i-th sample price in the sample space, p N-num is the upper limit of the interval after removing the quantity.

[0033] Furthermore, the specific process of step 3, converting the collected data is as follows:

[0034] a. First, discount according to the main quality indicators, that is, convert the price of representative specifications according to the calorific value and ash content indicators; the discount formula for thermal coal, lump coal, and PCI coal according to the calorific value indicator is as follows:

[0035]

[0036] In the formula, Pk represents the physical price of the sample, and k represents the actual calorific value of the sample data;

[0037] The discount formula of coking coal according to ash content index is as follows:

[0038] In the formula, Pj represents the converted price of the standard product of coking coal, Pja represents the original price of the sample, a represents the actual ash content of the sample data (%), and A represents the ash content of the representative standard product of coking coal (%);

[0039] b. After the above steps are completed, the price is discounted according to the auxiliary quality index, that is, the sulfur content index is converted into the price of the representative specification product; the conversion formula is as follows:

[0040] In the formula, P represents the converted price of the sample data, Ps represents the price without converting the sulfur content, s represents the actual sulfur content (%) of a certain sample data, and S represents the sulfur content (%) of a certain representative specification product.

[0041] Furthermore, in step 4, the price index is calculated, and the specific process is as follows:

[0042] Step 401, calculate the average price of the market unit:

[0043] The average price of a market unit is calculated using the simple average method, and the formula is:

[0044]

[0045] Where: Pt represents the average coal price of the market unit in the tth reporting period (or X / X / XXXX), and Pit represents the coal price of the i-th price sampling sample in the market unit in the tth calculation period;

[0046] Step 402: Calculate the average price of a certain product:

[0047] The average price of a product is calculated by the weighted average method with fixed weights. The weights are the approximate proportion of the trading volume of each region of the product. The calculation formula is:

[0048]

[0049] Where: Pp represents the average price of coal of this variety, Pip represents the average price of coal of the ith market unit involved in this variety, and Wip is the weight of the ith market unit;

[0050] Step 403: Calculate the average price of a certain area:

[0051] The average price of a region is calculated by the weighted average method with fixed weights. The weights are the approximate proportion of the trading volume of each variety in the region. The calculation formula is:

[0052]

[0053] Where: Pd represents the average coal price in the region, Pid represents the average coal price of the ith market unit in the region, and Wid represents the weight of the ith market unit;

[0054] Step 404, calculate the average price in Shaanxi:

[0055] The average price in Shaanxi is calculated by the weighted average method with fixed weights. There are two ways to calculate it. One is to calculate the weighted average price of each variety, and its weight is the approximate proportion of the transaction volume of each variety; the other is to calculate the weighted average price of each region, and its weight is the approximate proportion of the transaction volume of each region. The calculation results of the above two calculation methods are exactly the same; the calculation formula is:

[0056] P=ΣWdPd=ΣWpPp

[0057] In the formula, P represents the average price of Shaanxi coal, Pd represents the average price of the dth region, and Wd represents the weight of the dth region; Pp represents the average price of the pth variety, and Wp represents the weight of the pth variety;

[0058] Step 404: Calculate the price index:

[0059] The price indices at various levels, such as market unit, comprehensive for a certain product, comprehensive for a certain region, and comprehensive for Shaanxi, are all relative values ​​of the average price in the reporting period to the average price in the base period. If the base period is set at 100, the calculation formulas for the price indices at various levels are as follows:

[0060]

[0061] Where, It represents the Shaanxi coal price index in the tth reporting period, Pt represents the average price of Shaanxi coal in the tth reporting period, and P0 represents the average price of Shaanxi coal in the base period.

[0062] The Shaanxi coal price index calculation method provided by the present invention reflects the real situation of Shaanxi coal market changes, is basically consistent with the trend and amplitude of actual price changes in my country's coal market, and has the indicative function of a "weather vane" and "thermometer" reflecting Shaanxi coal market changes.

[0063] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 This is a schematic diagram of the calculation of Shaanxi coal price index.

[0065] Figure 2 This is a schematic diagram of the coal price index in the "Three West" regions of China's coal price index.

[0066] Figure 3 This is a schematic diagram of the spot price change trend of 5500 kcal thermal coal in Yulin, Shaanxi.

[0067] Figure 4 This is a schematic diagram of the average price change trend of 5500 kcal thermal coal in Taiyuan, Shanxi. DETAILED DESCRIPTION

[0068] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose, the specific implementation methods, structural features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and embodiments.

[0069] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] First, let's explain the basic concepts:

[0071] 1. Spot price

[0072] Spot price refers to the transaction price of a commodity in a spot transaction. Spot transaction refers to a transaction method in which the buyer and seller reach an agreement on the demand for physical commodities and the purpose of selling physical commodities, based on the supply and demand situation of commodities, and in accordance with the agreed payment method and delivery method, and immediately or within a short period of time to deliver physical commodities.

[0073] The "spot" in coal spot trading in this plan refers to the exchange and circulation of physical coal as the ownership of coal is transferred, which is essentially different from futures.

[0074] The "spot transaction" in this plan has two requirements: First, the time of reaching an agreement is in the current period, that is, the buyer and seller reach an agreement on "all" major terms of the transaction contract within the reporting period and give them legal effect that must be performed. The transaction counterparty is "randomly" found and agreed upon based entirely on the resources that the supplier may deliver within the spot delivery period and the demand of the demander. No agreement has been reached on any major terms in advance. Transactions that have agreed on transaction volume in annual or quarterly contracts and renegotiated prices in installments according to market changes are not considered spot transactions, and their transaction prices should be determined as long-term contract prices based on spot prices as pricing benchmarks. Second, it refers to transactions that deliver goods immediately after the transaction is completed or deliver goods in the "short term". The so-called "short term" refers to transactions that deliver goods immediately or in the "short term" according to the declaration and transportation procedures of the Shaanxi Provincial Railway Transport Capacity Plan. The delivery period for railway transportation is temporarily set at 45 days; the delivery period for automobile transportation is usually the current delivery, that is, delivery within the current reporting period, but for large-volume spot transactions, the delivery period may be longer, also temporarily set at 45 days.

[0075] The spot price referred to in this plan is the spot transaction price agreed upon by the buyer and seller at the current time. The first requirement is that the agreement is reached at the current time, which may not necessarily be delivered within the current reporting period, but may also be delivered within a specified time limit in the future; the second requirement is that the agreement is reached, which may not necessarily be a written contract; the third requirement is the price agreed upon in the "contract" or "agreement", rather than the settlement price finally determined according to the terms of the contract.

[0076] 2. Market Unit

[0077] Market unit refers to the market of coal of the same or similar varieties shipped by the same transportation method in a certain region, and also a certain regional market of a certain variety shipped by a certain transportation method. It is a market with market homogeneity, price linkage and relative independence. For example, the market of thermal coal with a calorific value of 5500 kcal / kg transported by automobile in Yulin, Shaanxi Province is defined as a market unit because the thermal coal with a calorific value of 5500 kcal / kg or close to 5500 kcal / kg shipped by automobile in Yulin has the same market characteristics due to the same transportation method, being in a similar region and having similar quality. Its price changes are often linked, and it has different price trends and change ranges compared with other regional markets (such as the 5500 kcal / kg thermal coal market in Xianyang, Shaanxi Province), or other varieties of markets in the region (such as the 5000 kcal / kg thermal coal market in Yulin), or the same variety of railway exported coal in the region.

[0078] 3. Price point

[0079] A price collection point refers to a specific location whose price data needs to be continuously tracked and collected for price index calculation, such as a coal mine in Yulin, Shaanxi, a coal distribution station in Yan'an, etc.

[0080] 4. Pricing unit

[0081] The price unit refers to an individual object whose price data needs to be continuously tracked and collected for the calculation of the price index, that is, an individual unit corresponding to a certain mode of transportation, a certain price point, a certain variety, a certain quality and a certain price component. For example, the price of a 5500 kcal washed mixed coal truck plate traded in a coal mine in Yulin area can be regarded as a price unit. The corresponding price location of this price unit is a coal mine in Yulin area, the corresponding variety is thermal coal, the corresponding quality is a calorific value of 5500 kcal or similar quality, the corresponding mode of transportation is automobile transportation, and the corresponding price component is the various elements contained in the truck plate price. Considering that coal-consuming process equipment has a strong adaptability to other indicators other than the main indicators such as calorific value, clean coal grade, and lump coal size, and other indicators also have rules for discounting to representative specifications, therefore, in principle, this plan does not use the origin and other quality indicators contained therein as the basis for dividing the price unit, but converts other quality indicators into the price of representative specifications according to the discount rules, so as to incorporate similar specifications into the price unit of representative specifications.

[0082] 5. Representative specifications

[0083] Representative specification products are product specifications that set pricing quality standards and delivery locations so that the same type and similar quality coal shipped from nearby locations by the same transportation method can be uniformly priced. For example, the index system of this scheme sets Yulin's steam coal with a calorific value of 5500 kcal / kg and a sulfur content of 0.3% as a representative specification product. The price of steam coal with similar quality shipped from nearby locations can be converted into the price of the representative specification product according to certain discount rules.

[0084] Example 1

[0085] A method for calculating the Shaanxi coal price index described in the present invention comprises the following steps:

[0086] Step 1: Establish data collection principles and collect data;

[0087] Step 2: Screen the collected data;

[0088] Step 3: Convert the collected data;

[0089] Step 4: Calculate the price index.

[0090] Furthermore, the step 1, formulating data collection principles, and the specific process of collecting data includes:

[0091] Step 101: Divide the market area. The principle of dividing the regional market is:

[0092] (1) The price gap within adjacent and interconnected regions is smaller than the price gap between them and their neighboring regions;

[0093] (2) Having the same or similar production and consumption characteristics, import and export characteristics, transportation routes and modes, and similar circulation patterns;

[0094] (3) The determining factors of market fluctuations are the same or similar;

[0095] In accordance with the above principles and combined with the actual operation of the Shaanxi coal market, the Shaanxi Price Index divides Shaanxi into four regional markets, namely:

[0096] (1) Yulin area (Yuyang District, Shenmu County, Fugu County, and Hengshan County);

[0097] (2) Yan'an area (Huangling County, Zichang County, Fu County, Baota District);

[0098] (3) Xianyang area (Bin County, Changwu County, Xunyi County, and Chunhua County);

[0099] (4) Guanzhong region (Tongchuan, Chenghe, Pubai, Hancheng, and Baoji).

[0100] Step 102: Divide the market into categories. The principles for dividing the market categories are:

[0101] A. They can be used as substitutes for each other in the market; first, they have the same or similar uses and user groups, and can be divided into coking coal, thermal coal, and anthracite; second, they have the same or similar quality, and can be divided into coking coal and coking coal, and thermal coal can be divided into several varieties according to different qualities;

[0102] B. Have considerable spot trading volume;

[0103] In accordance with the above principles and combined with the actual operation of the Shaanxi coal market, the Shaanxi Price Index divides Shaanxi into 7 market categories, namely:

[0104] (1) Thermal coal with a calorific value of 6,000 kcal / kg;

[0105] (2) 5500 kcal / kg thermal coal;

[0106] (3) 5000 kcal / kg thermal coal;

[0107] (4) 4500 kcal / kg thermal coal;

[0108] (5) Lump coal;

[0109] (6) Coking coal;

[0110] (7) Coal injection.

[0111] Step 103: Classify the transportation modes, and divide the transportation modes of Shaanxi coal into two modes: road transportation and railway transportation. Due to the limitation of railway transportation capacity, these two transportation modes are currently given equal importance.

[0112] Step 104, according to the principle of dividing the market units into transport modes, market areas, and market varieties, determine the specifications and varieties and the comprehensive index;

[0113] According to the above-mentioned principle of dividing the market units into two modes of transportation, four regions and seven varieties, based on the market structure of Shaanxi coal and the layout of the existing pricing system, 15 representative specifications are released taking into account the comprehensive transportation mode, and on this basis, nine comprehensive indexes are calculated, including one Shaanxi comprehensive index, four regional comprehensive indexes of Yulin, Yan'an, Xianyang and Guanzhong, and four variety comprehensive indexes of thermal coal, coking coal, pulverized coal and lump coal.

[0114] The 15 representative specifications of the Shaanxi coal price index indicator system released in the first phase include:

[0115] 1: Yulin 6000 kcal thermal coal;

[0116] 2: Yulin 5500 kcal thermal coal;

[0117] 3: Yulin lump coal;

[0118] 4: Yulin PCI;

[0119] 5: Yan'an 5500 kcal thermal coal;

[0120] 6: Yan'an 5000 kcal thermal coal;

[0121] 7: Yan'an lump coal;

[0122] 8: Yan'an coking coal;

[0123] 9: Xianyang 5500 kcal thermal coal;

[0124] 10: Xianyang 5000 kcal thermal coal;

[0125] 11: Xianyang 4500 kcal thermal coal;

[0126] 12: Xianyang lump coal;

[0127] 13: Guanzhong 5000 kcal thermal coal;

[0128] 14: Guanzhong 4500 kcal thermal coal;

[0129] 15: Guanzhong lump coal.

[0130] Step 105: Set the price collection points, determine the collection samples, and form a coal information collection network;

[0131] In terms of data collection, the Shaanxi Coal Price Index is based on the principles of broad representativeness, system comparability and objective authenticity. It closely relies on Shaanxi government departments, industry organizations, coal enterprises, coal trading centers, transportation and marketing enterprises, information service enterprises, shipping stations, etc., and collects coal spot transaction prices and related data at multiple levels and through multiple channels. At present, 92 price collection points have been set up in various regions of Shaanxi, and 132 collection samples have been determined, forming the Shaanxi coal information collection network, which basically covers the vast majority of spot trading volume in the Shaanxi coal trading market. Based on this network, the Shaanxi Coal Price Index can more comprehensively, timely and accurately reflect the price changes in the Shaanxi coal market.

[0132] Step 106: Determine the price collection period and base period, and complete data collection.

[0133] Price collection cycle

[0134] The price collection cycle is from last Friday to this Thursday. The data for this period must be submitted before 15:00 every Friday, and the price index must be calculated before 17:00 on Friday.

[0135] Base period

[0136] The Shaanxi Coal Price Index is a sub-index of the China Coal Price Index, which corresponds to and is consistent with the base period of the China Coal Price Index. The index also takes January 1, 2006 as the base period (100 points).

[0137] Furthermore, in step 2, the collected data is screened using the confidence interval method, and the calculation formula is as follows:

[0138]

[0139] in, represents the sample mean within the original data interval, s represents the sample standard deviation, and p min is the lower limit of the interval, p max is the upper limit of the interval, p i is the i-th sample price in the sample space.

[0140] Furthermore, in step 2, the collected data is screened using the median method, and the calculation formula is as follows:

[0141]

[0142] Among them, P is the sample space (ordered), N is the sample size in the sample space, and d ratio is the removal ratio, num is the number of removals, pmin is the lower limit of the interval, p max is the upper limit of the interval, p i is the i-th sample price in the sample space, p N-num is the upper limit of the interval after removing the quantity.

[0143] In order to realize the important function of being a pricing tool indicator for coal trading, it is necessary to convert the quality specifications of the original price data into representative specifications. Usually, the prices of other coals of similar quality specifications of the same variety are converted into representative specifications according to certain price adjustment rules. For thermal coal, lump coal, and PCI coal, calorific value and sulfur content are relatively important conversion quality indicators. For coking coal, this scheme converts according to ash content and sulfur content.

[0144] Furthermore, the specific process of step 3, converting the collected data is as follows:

[0145] a. First, discount according to the main quality indicators, that is, convert the price of representative specifications according to the calorific value and ash content indicators; the discount formula for thermal coal, lump coal, and PCI coal according to the calorific value indicator is as follows:

[0146]

[0147] In the formula, Pk represents the physical price of the sample, and k represents the actual calorific value of the sample data;

[0148] The discount formula of coking coal according to ash content index is as follows:

[0149] In the formula, Pj represents the converted price of the standard product of coking coal, Pja represents the original price of the sample, a represents the actual ash content of the sample data (%), and A represents the ash content of the representative standard product of coking coal (%);

[0150] b. After the above steps are completed, the price is discounted according to the auxiliary quality index, that is, the sulfur content index is converted into the price of the representative specification product; the conversion formula is as follows:

[0151] In the formula, P represents the converted price of the sample data, Ps represents the price without converting the sulfur content, s represents the actual sulfur content (%) of a certain sample data, and S represents the sulfur content (%) of a certain representative specification product.

[0152] Furthermore, the Shaanxi Price Index is compiled using the weighted arithmetic average method, and in principle, fixed weights are used for calculation. The weights of each variety and region are determined based on the proportion of its spot trading volume in the total spot trading volume in the past three years. There is no accurate statistical data on this proportion, and it can only be roughly determined based on research and structural analysis of the market.

[0153] The main basis is: the main production structure, spot transaction structure, and transportation structure of each type of coal in each region: the output of large and medium-sized coal enterprises and their market sales (average volume in the past three years, the same below), the railway and road transportation volume in spot sales, the output of local coal mines and their market sales, the railway and road transportation volume in spot sales, etc. After conducting research around the above issues, the total spot transaction volume in a certain region and the spot sales volume of each type of coal were roughly determined.

[0154] The above investigation and analysis is the basic analysis for determining the weight of each market unit. On this basis, the weight of each pricing unit is determined according to the coal trading volume of the pricing points arranged in each market unit and their proportional relationship.

[0155] Furthermore, in step 4, the price index is calculated, and the specific process is as follows:

[0156] Step 401, calculate the average price of the market unit:

[0157] The average price of a market unit is calculated using the simple average method, and the formula is:

[0158]

[0159] Where: Pt represents the average coal price of the market unit in the tth reporting period (or X / X / XXXX), and Pit represents the coal price of the i-th price sampling sample in the market unit in the tth calculation period;

[0160] Step 402: Calculate the average price of a certain product:

[0161] The average price of a product is calculated by the weighted average method with fixed weights. The weights are roughly determined by the proportion of the trading volume of each region of the product. The calculation formula is:

[0162]

[0163] Where: Pp represents the average price of coal of this variety, Pip represents the average price of coal of the ith market unit involved in this variety, and Wip is the weight of the ith market unit;

[0164] Step 403: Calculate the average price of a certain area:

[0165] The average price of a region is calculated by the weighted average method with fixed weights. The weights are the approximate proportion of the trading volume of each variety in the region. The calculation formula is:

[0166]

[0167] Where: Pd represents the average coal price in the region, Pid represents the average coal price of the ith market unit in the region, and Wid represents the weight of the ith market unit;

[0168] Step 404, calculate the average price in Shaanxi:

[0169] The average price in Shaanxi is calculated by the weighted average method with fixed weights. There are two ways to calculate it. One is to calculate the weighted average price of each variety, and its weight is the approximate proportion of the transaction volume of each variety; the other is to calculate the weighted average price of each region, and its weight is the approximate proportion of the transaction volume of each region. The calculation results of the above two calculation methods are exactly the same; the calculation formula is:

[0170] P=ΣWdPd=ΣWpPp

[0171] In the formula, P represents the average price of Shaanxi coal, Pd represents the average price of the dth region, and Wd represents the weight of the dth region; Pp represents the average price of the pth variety, and Wp represents the weight of the pth variety;

[0172] Step 404: Calculate the price index:

[0173] The price indices at various levels, such as market unit, comprehensive for a certain product, comprehensive for a certain region, and comprehensive for Shaanxi, are all relative values ​​of the average price in the reporting period to the average price in the base period. If the base period is set at 100, the calculation formulas for the price indices at various levels are as follows:

[0174]

[0175] Where, It represents the Shaanxi coal price index in the tth reporting period, Pt represents the average price of Shaanxi coal in the tth reporting period, and P0 represents the average price of Shaanxi coal in the base period.

[0176] To sum up, the Shaanxi Coal Price Index calculation method reflects the real situation of changes in the Shaanxi coal market, and is basically consistent with the trend and amplitude of actual price changes in my country's coal market. It plays the role of a "barometer" and "thermometer" reflecting changes in the Shaanxi coal market.

[0177] The basic function of the calculation method of the Shaanxi coal price index is to comprehensively, timely and accurately describe the average change trend and change range of the Shaanxi coal market transaction price (i.e. "spot price"). The index reflects the immediate changes in the market environment in the short term, and reflects the combined impact of changes in coal supply and demand and changes in coal costs in the medium and long term. The price fluctuation characteristics described by the index are the collective price orientation of most market players, not necessarily the price orientation of most trading volumes.

[0178] The more important function of the Shaanxi Coal Price Index calculation method is to serve as a reference benchmark for coal trading pricing and become a "pricing tool indicator". First, it promotes the convergence of spot trading prices in Shaanxi, including the trading samples involved in the formation of the price index, which can all refer to the index to determine the spot trading price, so that the original discrete spot price samples tend to be consistent; second, it serves as a reference benchmark for large trading entities to regularly adjust the long-term contract prices based on market changes, and is used to establish a flexible pricing mechanism for long-term contract transactions; third, it serves as a reference for coal trading pricing in Shaanxi's surrounding areas and other related areas.

[0179] Example 2

[0180] Using the Shaanxi coal price index calculation method described in Example 1, Figure 1 This is a schematic diagram of the calculation of the Shaanxi coal price index. Figure 2 The coal price index of the "Three Wests" region in China is basically consistent with the coal price index of the "Three Wests" region shown in the figure. The "Three Wests" region includes Shanxi, Shaanxi and western Inner Mongolia. The coal price index of the "Three Wests" region is a sub-index of the China Coal Price Index. The above conclusion reflects that the Shaanxi coal market has a high correlation with other coal markets in the "Three Wests" region. Figure 3 The trend and magnitude of the spot price of a 5500 kcal thermal coal in Yulin, Shaanxi Province are basically the same. Figure 4 The average price change trend of 5500 kcal thermal coal in Taiyuan, Shanxi Province is roughly the same.

[0181] From the above comparison, it can be seen that the calculation method of the Shaanxi Coal Price Index accurately reflects the real situation of changes in the Shaanxi coal market, and is basically consistent with the trend and amplitude of actual price changes in my country's coal market. It has the indicative function of a "barometer" and "thermometer" reflecting changes in the Shaanxi coal market.

[0182] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for calculating the Shaanxi coal price index, characterized in that: The steps include: Step 1: Establish data collection principles and collect data; Step 2: Screen the collected data; Step 3: Convert the collected data; Step 4: Calculate the price index.

2. A method for calculating the Shaanxi coal price index according to claim 1, characterized in that: The step 1, formulating data collection principles, and the specific process of collecting data includes: Step 101: Divide the market area. The principle of dividing the regional market is: (1) The price gap within adjacent and interconnected regions is smaller than the price gap between them and their neighboring regions; (2) Having the same or similar production and consumption characteristics, import and export characteristics, transportation routes and modes, and similar circulation patterns; (3) The determining factors of market fluctuations are the same or similar; Step 102: Divide the market into categories. The principles for dividing the market categories are: A. They can be used as substitutes for each other in the market; first, they have the same or similar uses and user groups, and can be divided into coking coal, thermal coal, and anthracite; second, they have the same or similar quality, and can be divided into coking coal and coking coal, and thermal coal can be divided into several varieties according to different qualities; B. Have considerable spot trading volume; Step 103, classify the transportation modes, and classify the transportation modes of Shaanxi coal into two modes: road transportation and railway transportation; Step 104, according to the principle of dividing the market units into transport modes, market areas, and market varieties, determine the specifications and varieties and the comprehensive index; Step 105: Set the price collection points, determine the collection samples, and form a coal information collection network; Step 106: Determine the price collection period and base period, and complete data collection.

3. The method for calculating the Shaanxi coal price index according to claim 1, characterized in that: In step 2, the collected data is screened using the confidence interval method, and the calculation formula is as follows: in, represents the sample mean within the original data interval, s represents the sample standard deviation, and p mi n is the lower limit of the interval, p max is the upper limit of the interval, p i is the i-th sample price in the sample space.

4. A method for calculating the Shaanxi coal price index according to claim 1, characterized in that: In step 2, the collected data is screened using the median method, and the calculation formula is as follows: Among them, P is the sample space (ordered), N is the sample size in the sample space, and d ratio is the removal ratio, num is the number of removals, p min is the lower limit of the interval, p max is the upper limit of the interval, p i is the i-th sample price in the sample space, p N-num is the upper limit of the interval after removing the quantity.

5. The method for calculating the Shaanxi coal price index according to claim 1, characterized in that: The specific process of step 3, converting the collected data, is as follows: a. First, discount according to the main quality indicators, that is, convert the price of representative specifications according to the calorific value and ash content indicators; the discount formula for thermal coal, lump coal, and PCI coal according to the calorific value indicator is as follows: In the formula, Pk represents the physical price of the sample, and k represents the actual calorific value of the sample data; The discount formula of coking coal according to ash content index is as follows: In the formula, Pj represents the converted price of the standard product of coking coal, Pja represents the original price of the sample, a represents the actual ash content of the sample data (%), and A represents the ash content of the representative standard product of coking coal (%); b. After the above steps are completed, the price is discounted according to the auxiliary quality index, that is, the sulfur content index is converted into the price of the representative specification product; the conversion formula is as follows: In the formula, P represents the converted price of the sample data, Ps represents the price without converting the sulfur content, s represents the actual sulfur content (%) of a certain sample data, and S represents the sulfur content (%) of a certain representative specification product.

6. A method for calculating the Shaanxi coal price index according to claim 1, characterized in that: The step 4, calculating the price index, the specific process is as follows: Step 401, calculate the average price of the market unit: The average price of a market unit is calculated using the simple average method, and the formula is: Where: Pt represents the average coal price of the market unit in the tth reporting period (or X / X / XXXX), and Pit represents the coal price of the i-th price sampling sample in the market unit in the tth calculation period; Step 402: Calculate the average price of a certain product: The average price of a product is calculated by the weighted average method with fixed weights, where the weights are the approximate proportion of the trading volume of the product in each region; The calculation formula is: Where: Pp represents the average price of coal of this variety, Pip represents the average price of coal of the ith market unit involved in this variety, and Wip is the weight of the ith market unit; Step 403: Calculate the average price of a certain area: The average price of a region is calculated by the weighted average method with fixed weights, where the weights are the approximate proportion of the trading volume of each product in the region; The calculation formula is: Where: Pd represents the average coal price in the region, Pid represents the average coal price of the ith market unit in the region, and Wid represents the weight of the ith market unit; Step 404, calculate the average price in Shaanxi: The average price in Shaanxi is calculated by the weighted average method with fixed weights. There are two ways to calculate it. One is to calculate the weighted average price of each variety, and its weight is the approximate proportion of the transaction volume of each variety; the other is to calculate the weighted average price of each region, and its weight is the approximate proportion of the transaction volume of each region. The calculation results of the above two calculation methods are exactly the same; the calculation formula is: PWD In the formula, P represents the average price of coal in Shaanxi, Pd represents the average price of the dth region, and Wd represents the weight of the dth region; Pp represents the average price of the p-th variety, and Wp represents the weight of the p-th variety; Step 404: Calculate the price index: The price indices at various levels, such as market unit, comprehensive for a certain product, comprehensive for a certain region, and comprehensive for Shaanxi, are all relative values ​​of the average price in the reporting period to the average price in the base period. If the base period is set at 100, the calculation formulas for the price indices at various levels are as follows: Where, It represents the Shaanxi coal price index in the tth reporting period, Pt represents the average price of Shaanxi coal in the tth reporting period, and P0 represents the average price of Shaanxi coal in the base period.

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