The sample-based monthly volume index is adjusted retrospectively (currently after about 18 months) against an annual volume index of industrial output. The annual volume index of industrial output is calculated by dividing changes in gross value by industry by a unit value index calculated with data from statistics on manufacturing commodities (volumes and values by establishment). The obtained Paasche's volume index is regarded as a substitute to value added at fixed prices.
Percentage of the production capacity of manufacturing that is in use during a statistical reference month. The statistics are based on data collected monthly from establishments.
As far as possible the volume index of industrial output is calculated using volume data obtained from establishments. However, in some cases an establishment may not be able provide data on the volume of its output. In these cases, the establishment is asked for data on some other variables describing output, in other words proxy variables, that are considered as indicative of its volume. Examples of proxy variables include hours worked, raw materials consumed or value of output.
The volume index of industrial output describes the relative change in the volume of industrial output when compared with a specific base time period. In the beginning of 2002, the index with fixed weights was replaced with an index with changing weights, which takes the structural change occurring in industry into account better than the index with fixed weights.