prisindeks

Prisindeks (price index) is a statistical measure that tracks changes in the average price level of a defined set of goods and services over time. It serves as a measure of inflation and is used to adjust wages, pensions, contracts, and macroeconomic indicators. A price index requires a base period, a market basket of items, and weights reflecting their relative importance. The index value is typically normalized to 100 in the base period; subsequent values indicate price changes relative to that period.

Common construction methods include Laspeyres, which uses base-period quantities as weights; Paasche, which uses current-period quantities; and chain-linked indexes that update weights more frequently. Types of prisindeks include consumer price indices (CPI), producer price indices (PPI), and price deflators such as the GDP price deflator. The choice of method and basket affects measured inflation, especially through substitution and quality-change biases.

Interpretation and use: the annual or monthly percentage change in a prisindeks expresses the inflation rate. Policymakers and researchers rely on prisindeks to monitor price movements, compare real values over time, and adjust contracts and policies. Limitations include substitution bias, changes in product quality, the introduction of new goods, outlet coverage, and geographic scope. The interpretation of an index value is relative; a higher index indicates higher prices, not a higher quantity consumed. Real values are obtained by dividing nominal values by the prisindeks and multiplying by a base value.