inflationsindex

An inflationsindex is a statistical measure that tracks changes in the general price level of a representative basket of goods and services over time. It serves as an indicator of inflation and is used to adjust wages, contracts, pensions, and other monetary values, as well as to analyze real economic growth.

Calculation and interpretation

Prices for a fixed or changing basket are observed over time and combined into a single index. The index is usually normalized to a base year, often with a value of 100. The inflation rate for a period is the percentage change of the index from the previous period. Different indices may measure slightly different price ranges or sectors.

Common types and methods

- Consumer price index (CPI)

- Harmonised index of consumer prices (HICP)

- Producer price index (PPI)

- GDP deflator

Other methodological choices include chained indices versus fixed-base indices and different aggregation formulas such as Laspeyres, Paasche, or Fisher indices.

Uses and limitations

Inflationsindices inform monetary policy, guide wage negotiations and pension adjustments, and help deflate nominal values to assess real changes. Limitations include substitution bias, quality changes, the introduction of new goods, and differences in basket composition or geographic coverage, which can affect comparability across countries or time periods.

Data sources and scope

National statistical offices and international bodies publish inflation indices. In the European Union, HICP is harmonized across member states; in the United States, CPI data are published by the Bureau of Labor Statistics. The term inflationsindex is commonly used in German-speaking contexts to refer to such measures in general.