Microeconomic analysis of the main ways of decomposition of the cost index

The article considers a microeconomic analysis of the main options for decomposing the value index into price and quantity change factors, as a result of which it becomes possible to interpret these options in terms of changing the expectations of either the consumer or the producer. The purpose of the study is to show that the Laspeyres, Paasche and Fisher indices have not only an estimated, but also an important content function, reflecting changes in the market expectations of economic agents. To achieve the goal, a comparative analysis of the basic formulas of the concepts of adaptive and rational expectations was carried out, as well as a meaningful analysis of the cost aggregates that are components of the Laspeyres, Paasche and Fisher indices, and a schematic diagram of the formation of adaptive and rational expectations was developed. As a methodological basis for solving the problem, the expectation theory, the analogy method, the index method of factor reversibility, and the minimum basis method were used. It is shown that Laspeyres indices are the essence of changes in adaptive expectations, Paasche indices are changes in rational expectations of producers and consumers, and Fisher indices are a joint change in adaptive and rational expectations of economic agents. It is advisable to interpret one of the main methods of decomposition of the cost index into factors as a “buying” method that meets the expectations of the consumer, another — as a “selling” method that meets the expectations of the manufacturer, a decomposition method, the third — as a “compromise” between market expectations of economic agents.