There are three methods of calculating GDP: the production method, the income method, and the expenditure method.　　(i) Production method The production method is a method of calculating GDP from the production point of view. From the total value of products and services produced and provided by each sector of the national economy in a certain period of time, the value of intermediate products invested in the production process is deducted, so as to obtain the value added by each sector, and the sum of the value added by each sector is the gross domestic product (GDP). The formula is: total output - intermediate inputs = value added GDP = the sum of the value added of each sector 1, total output: refers to the resident unit in a certain period of time the production of all the goods and services of the value of the sum, including both the value of the new value, including the value of the transfer of the value to reflect a certain range of sectors of the production and business activities of the total scale, also known as the total value of production. Gross output is calculated at producer prices. The total output of each major sector is calculated as follows: The total output of agriculture, forestry, animal husbandry and fishery is the gross value of agricultural production, calculated according to the product method, i.e., by multiplying the output of agricultural products by the price of the unit of product during the accounting period, in which the output of agricultural products includes the output of agricultural products that are produced by the producers for their own use. Total industrial output is calculated using the factory method, i.e., industrial enterprises as a whole, calculated according to the final results of the enterprise's production activities, and the value of products within the same enterprise is not allowed to be double-counted. It includes the value of finished products produced during the accounting period, the value of industrial operations and the value of the difference between the end and beginning of the period for self-made semi-finished products and work-in-progress. With the introduction of VAT, total industrial output is equal to total industrial output plus output tax. The total output of the construction industry is the gross output value of the construction industry, which refers to the value of the works completed by the construction enterprises or self-employed construction enterprise units during the accounting period. Specifically, it includes the output value of construction works, the output value of machinery and equipment installation works, the repair output value of houses and structures, and the manufacturing value of non-standard equipment. The total output of the construction industry is generally calculated on the basis of the physical volume or progress of completed works multiplied by the budget unit price. Transportation, warehousing and postal industry total output is equal to its operating income, is the total income of all kinds of transportation, postal and telecommunications business during the accounting period. Specifically, it includes the total revenue of transportation such as highway, waterway, air, railroad, pipeline, etc., and the operating revenue of post and telecommunications business such as telephone, telegraph and transmission of mail. The total output of wholesale and retail trade is equal to the business surcharge, which is the net proceeds from the sale of merchandise minus the cost of goods sold, commonly referred to as gross profit. In order to avoid double counting in the distribution process and to maintain the consistency of the purchase price of goods, it is necessary to deduct the transportation and loading and unloading handling charges paid to external parties. The total output of the accommodation and food service industry is equal to its operating income. The total output of the banking sector is equal to the virtual service income plus actual service fee income from financial media service activities. Insurance gross output equals the difference between premium income and claims expenses plus other operating income. Gross output of real estate includes gross output of real estate development and operation, gross output of property management, gross output of real estate intermediary services and gross output of services for resident-owned housing. The total output of other services is calculated separately for both for-profit and non-profit units. The total output of for-profit units is their operating (business) income, such as the operating income of social services. Non-profit units are mainly business, administrative units and social organizations, generally no operating income, or a small amount of operating income but can not offset the expenditure, the total output of these sectors is the accounting period for the cost of providing services to the community, according to the recurring operating expenditures plus virtual depreciation of fixed assets, do not calculate the operating surplus. 2, intermediate inputs: is a permanent unit of a certain period of time in the production process, consumption and use of non-fixed assets such as raw materials, fuel, power and the value of various services. Calculation of intermediate inputs must have two conditions: one is consistent with the scope of the caliber of the calculation of total output, that is, the calculation of the value of intermediate products consumed in the process of production and operation corresponding to the total output. Therefore, the calculation method of intermediate inputs in each sector corresponds to the calculation method of its total output. For example, if the total industrial output is calculated according to the factory method, and no double counting is allowed within the factory, then its intermediate inputs should be calculated according to the purchased raw materials, fuel and power consumed in the production and the service costs paid to the outside world; the total agricultural output is calculated according to the product method, and its intermediate inputs include both the purchased and the intermediate products (such as seeds and fodder) that are self-produced and self-consumed. The value of intermediate inputs includes both purchased and self-produced intermediate products (e.g., seed, feed). Second, generally for the current period of one-time use, that is, the current consumption of non-durable goods not belonging to the fixed assets; low-value consumables are calculated on the basis of the amortized portion of the current period. 3, value added: is the total output minus the balance of intermediate inputs, is the value of material goods and services produced by the production unit exceeds the value of intermediate inputs consumed in the production process after the difference between the part. Reflects the final results of the production and business activities of each sector and unit within a certain period of time. (ii) Income method The income method is a method of calculating GDP from the point of view of the income generated by each factor of production in the production process. That is, the value added of each resident unit is equal to the sum of four items: compensation of laborers, depreciation of fixed assets, net production tax and operating surplus. These four items are also referred to as the initial input value in input-output. The sum of the value added of each resident unit is GDP, which is calculated as follows: GDP (gross domestic product) = compensation of workers + depreciation of fixed assets + net production tax + operating surplus 1, compensation of workers: refers to the various forms of compensation received by laborers from the production units engaged in production activities, including all forms of income in the form of money and in kind received by the laborers from the units of production through various channels and the individual. It includes all income in money and in kind that workers receive from production units through various channels and the income that individual workers receive through their labor. There are four main forms: first, wages, second, benefits, third, labor remuneration equivalent to the nature of wages paid to individual workers from profits or costs, and fourth, income in kind, which refers to the value of agricultural and sideline products produced by peasants and used for their personal consumption, as well as the value of in-kind goods received by laborers from the units free of charge or at a price lower than the market price. 2. Depreciation of fixed assets: it is the value of fixed assets consumed by the resident unit during the accounting period for production activities and withdrawn. Depreciation of fixed assets is not the value of the new creation of production activities in the current period, but the value of fixed assets consumed in production, is a transfer value. the reason why the GDP includes this part of the transfer value, is because the depreciation of fixed assets is free from fixed assets as depreciation into the cost, the depreciation recorded in the cost of the depreciation is also as a depreciation fund is raised for new investment in fixed assets into the enterprise's capital cycle movement, rather than being consumed out like other costs, and from this point of view it is similar to value added labor compensation and operating surplus. In addition, from the point of view of income, calculating depreciation in value added can avoid the fluctuation of value added due to calculating depreciation in intermediate inputs, which will bring about different sizes of operating surpluses due to different sizes of depreciation. This problem is avoided if depreciation is calculated in value added. Therefore, if depreciation is calculated in value added, it can improve the accuracy and consistency of GDP calculation and also enhance the comparability of GDP. 3. Net production tax: It is the difference between the production tax paid by each sector to the government and the production subsidy paid by the government to each sector. Taxes on production are taxes levied by the government on the production, sale, purchase, and use of goods and services by each sector. There are three main forms: first, sales tax, and second, tax into the cost, which refers to the tax levied by the state on production units for engaging in production activities, but some industries treat this tax uniformly as sales tax. Third, various surcharges and fees. Production subsidies are subsidies paid by the government to certain sectors for the purpose of controlling prices and supporting production, including price subsidies for food enterprises and subsidies for policy losses of enterprises. After the implementation of value-added tax, the production tax also includes the value-added tax payable for the current period (the difference between the output tax of products and the input tax of purchased goods and services). 4、Operating surplus: It is the remaining part of the total output after deducting intermediate inputs, depreciation of fixed assets, compensation of laborers, and net production tax, which is the remaining share of the value added created by the resident unit after compensating for the fixed assets, distributing to the laborers, and paying taxes to the state. (iii) Expenditure method The expenditure method is a method of calculating GDP and its destination from the point of view of end-use, which consists of final consumption of goods and services, gross capital formation and net exports. The formula is: GDP (gross domestic product) = final consumption + gross capital formation + net exports 1, final consumption: refers to the resident units in the accounting period for the final consumption of goods and services, including residential consumption and government consumption. Among them, residents' consumption is all the material products and services purchased by residents of permanent residence units in the accounting period to meet their individual final consumption needs, including commodity consumption, cultural and living services consumption, housing and water, electricity and gas consumption; government consumption is the services provided to the whole society by social public ****services departments in order to satisfy the needs of the public, as well as the services provided to enterprise employees to satisfy their public ****services needs. Services provided by enterprises to meet the public **** needs of their employees. 2. Gross capital formation: It refers to the aggregate of investment expenditures of resident units during the accounting period, and is divided into two items: fixed capital formation and increase in inventories. Fixed capital formation refers to the value of fixed assets purchased and constructed by the resident unit during the accounting period, including all kinds of tangible fixed assets and intangible fixed assets. Increase in inventories is the value of changes in inventories at the end of the accounting period and at the beginning of the period for resident units. Total capital formation = fixed capital formation + increase in inventories Increase in inventories = the amount of inventory at the end of the period - the amount of inventory at the beginning of the period 3, net exports of goods and services: is the difference between the total amount of exports minus the total amount of imports, such as the total amount of imports is greater than the exports are expressed as a negative number. Exports refers to resident units to non-resident units sold and non-remunerated total value of goods and services; imports refers to resident units from non-resident units purchased and non-remunerated total value of goods and services. Net regional exports also include inflows and outflows. Net Exports = Gross Exports of Goods and Services - Gross Imports of Goods and Services Theoretically, GDP calculated through three different methods, namely, the production method, the income method, and the expenditure method, is equal, i.e., GDP calculated by the production method is equal to GDP calculated by the income method, and to GDP calculated by the expenditure method, which is referred to as triple-sided equivalence. That is to say, the results of the production of social final products and income distribution and end use should be equal, so it is necessary to keep the caliber of calculation of the three methods consistent. However, in the actual calculation, due to different sources of information, some differences in the calculation results will appear, called statistical error, is normal. The three methods have their own characteristics and complement each other. As far as our province is concerned, all three methods are used when accounting for annual GDP, and the production and income methods are usually used when accounting for quarterly GDP.