The formula for calculating the CPI is CPI = (the value of a group of fixed commodities at current prices / the value of a group of fixed commodities at base-period prices) × 100
We have discussed and exchanged extensively on the method of compiling the CPI with international organizations such as the International Monetary Fund (IMF) and peer experts in some countries, and in accordance with the requirements of the IMF General Data Dissemination System (GDDS). System (GDDS) requirements to hang on the IMF website. At present, China's CPI survey is divided into eight categories, including food, tobacco, alcohol and supplies, clothing, household equipment and services, health care and personal goods, transportation and communication, entertainment, education and cultural goods and services, and housing, with ****263 basic classifications (93SNA, the international standard for classifications), and about 700 kinds of commodities and service items. It is mainly based on the consumption patterns and habits of China's urban and rural residents, the consumption expenditure data of nearly 120,000 urban and rural households (of which nearly 50,000 are urban and nearly 70,000 are rural) selected with reference to the principle of sample survey, and determined in conjunction with other relevant information. The scope of the price survey involves more than 500 cities and counties and more than 50,000 survey outlets in 31 provinces (autonomous regions and municipalities) across the country. The national survey system directly under the National Bureau of Statistics adopts the direct survey method of fixing people, time and place, with nearly 3,000 full-time price surveyors going to different types and sizes of farmers' markets and stores to collect price information on the spot. For commodities that are closely related to the lives of residents and have more frequent price changes, prices are investigated at least once every five days, thus ensuring that the CPI can timely and accurately reflect changes in market prices.