consumer price index (CPI)

Consumer price index (Consumer price index (CPI) is a relative number that measures the price level of consumer goods and services over time, and reflects the changing trend and degree of the price level of goods and services purchased by residents. Its annual change rate is usually used to reflect the degree of inflation or austerity; CPI and its sub-indices are also important reference for calculating the real value of GDP, assets, liabilities, consumption and income.

The compilation method of CPI is to select representative specifications from many measurement objects, collect their price data, calculate the average price and individual price index of these representative specifications, then calculate the basic classification price index by geometric average, and then calculate the small, medium and large price indexes step by step by weighted average method until the total price index. According to the interpretation of CPI indicators by the National Bureau of Statistics, the calculation process is as follows:

First of all, the National Bureau of Statistics and local statistical departments determine the classification for calculation.CPI’s goods and services and survey outlets. According to the sampling survey data of household consumption expenditure of urban and rural residents in China, the National Bureau of Statistics uniformly determines the categories of goods and services, including: food, tobacco and alcohol, clothing, housing, daily necessities and services, transportation and communication, education, culture and entertainment, medical care, and other supplies and services, which basically cover all consumption contents of urban and rural residents. About 500 cities and counties were selected nationwide, and there were 63,000 survey outlets to determine the collection price, including grocery stores, department stores, supermarkets, convenience stores, professional markets, specialty stores, shopping centers, farmers’ markets and service consumption units.

Second, according toIn the way of "fixed person, fixed point and fixed time", the statistical department sends investigators to the survey outlets to collect prices on the spot. At present, there are about 4,000 price investigators in 500 cities and counties in 31 provinces (autonomous regions and municipalities). The frequency of price collection varies from commodity to commodity. For the food in CPI, such as grain, pork, beef, mutton and vegetables, which are closely related to residents’ lives and have relatively frequent price changes, the price is investigated once every five days; For most industrial products such as clothing, shoes and hats, durable consumer goods, transportation and communication tools, the price is investigated 2-3 times a month; For water, electricity and other government pricing projects, the prices are investigated and verified once a month.

Finally, according to the original price data after the audit, calculate a single commodity or service item andPrice indices of 268 basic categories. Then calculate the category price index and CPI according to the corresponding weights of each category.

our countryThe weight in CPI is mainly determined according to the detailed proportion of consumption expenditure of various commodities and services of urban and rural households in China. CPI summary calculation method adopts chain pull formula to compile month-on-month ratio, month-on-month ratio and fixed base price index.

CPI is equal to 100, indicating that the comprehensive price has not changed during the reporting period compared with the base period; The consumer price index is greater than 100, which means that the comprehensive price rises in the reporting period compared with the base period. The higher the price index, the more the price rises. The consumer price index is less than 100, which shows that the comprehensive price in the reporting period is lower than that in the base period.