Index system refers to a whole composed of several indexes because of their economic relevance and quantitative calculation. Its most typical performance is that the product of several factor indexes should be equal to the total change index. For example, sales index = sales index × sales price index = output index × product price index = total wage index = number of employees × average wage index of employees.

The function of index system:

1. Reflect the direction and degree of things change.

2. Reflect the spatial differences of things, such as the regional difference index of consumer prices.

3. Reflect a certain proportional relationship between things, such as the comprehensive price index of industrial and agricultural commodities.

4. It is used to analyze the changes of complex social and economic aggregates affected by various factors.

1. Principles for compiling the average index: arithmetic average index and average index. When the denominator data of single index and comprehensive index are mastered, the comprehensive index can be changed into weighted arithmetic average index. When the molecular data of single index and comprehensive index are mastered, the comprehensive index can be transformed into weighted harmonic average index. Weighted arithmetic average index and weighted harmonic average index, as the deformation of comprehensive index, also have the characteristics of comprehensive index in essence.

Second, the general characteristics of the index system:

1, a single indicator in an indicator system with three or more indicators can be calculated quantitatively, for example, the price index can be calculated when the sales index and the sales index are known.

2. The total variance difference of phenomena is equal to the sum of variance differences of various phenomena. Sales index of several commonly used index systems = price index × sales increase or decrease of sales index = price increase or decrease+sales increase or decrease.

3. Gross output value index = price index × product output index

4. Production cost index = unit cost index × product output index = increase or decrease of production cost caused by unit cost change+increase or decrease of production cost caused by product output change.

5. Product output index = labor productivity index × number of employees Product output increase or decrease = labor productivity increase or decrease+number of employees increase or decrease.

Third, the factor analysis method is based on the principle of exponential method, and then analyzes the changes of things affected by many factors to observe the influence of one factor change and fix other factors, so it is item-by-item analysis and item-by-item substitution, so it is called factor analysis method or series substitution method. The factors that affect the development of things should be divided into quantitative indicators and quality indicators. But both of them are relative and should be determined by comparison and identification in a certain economic environment. 2. Follow the general principle of determining the same measurement factor. When observing the changes of quality indicators, the same measurement factors should be fixed during the reporting period.

Fourth, the index system mainly has the following three functions: the index system is the basis of factor analysis. That is, the index system can be used to analyze the influence direction and degree of various factors in the total change of complex economic phenomena. Use the relationship between indicators to calculate each other. For example, the general merchandise sales index in China is often calculated according to the general merchandise sales index and the general price index. That is, the sales index-sales index-price index of commodities. When compiling the total index with the comprehensive index method, the index system is also one of the bases for determining the period of the same measurement factor. Because the index system is the basis of factor analysis, it is required to maintain a certain relationship between indicators in quantity. Therefore, if the base period price is used as the same measurement factor when compiling the product output index, the product output in the reporting period must be used as the same measurement factor when compiling the product price index; If the price in the reporting period is used as the same measurement factor when compiling the product output index, then the product output in the base period must be used as the same measurement factor when compiling the product price index.