Indeksnivå

Indeksnivå is the numerical value that represents the position of a statistical index at a specific point in time. It indicates how much the measured variable has changed relative to a defined base period, and it is usually expressed as a number, often with the base value set to 100.

Indices are constructed from a set of items, prices, or prices of assets, combined using weights. The current index level is typically calculated as the ratio of the current value to the base value, multiplied by the base index value. Different methods exist for weighting, such as Laspeyres, Paasche, or Fisher, and these choices affect how the level evolves over time. Stock indices, for example, commonly use market capitalization weighting, while consumer price or producer price indices use price-based methods.

Common examples of index levels include the consumer price index (CPI) level, which tracks changes in the cost of a fixed basket of goods and services, and stock market index levels that reflect aggregate movements in a set of listed shares. Index levels are also used to adjust economic data for inflation, compare economic performance across periods, and index wages, pensions, or contracts to maintain purchasing power.

Interpretation and limitations: While index levels provide a compact summary of complex data, they depend on the choice of base period, basket composition, and weighting scheme. Methodological changes or rebasing can alter levels. Indices may also be affected by substitution, quality changes, or the introduction of new goods, which can complicate direct comparisons over time.