1.2 Indices are used in comparisons

An index calculated from a time series allows us to compare litres and kilograms, but only in relation to the magnitude of change. From index values we can draw no inferences about whether alcohol, sugar, coffee or tobacco consumption in Finland is high or low. We will need to have original consumption data in order to understand the significance of each item. For example, the significance of increasing alcohol consumption can only be understood when the level of consumption in Finland is compared to other European countries.

Per capita alcohol consumption in selected European countries in 2000, litres of 100% alcohol

Source: Statistical Yearbook of Finland 2002, Table 656

Indices are most commonly used for purposes of comparisons over time, but they can obviouslybe used in any comparisons. For example, we can decide to set the Finnish value as the reference point at 100 and express the figures for other countries as indices in relation to this base value.

Per capital alcohol consumption in selected European countries in 2000, litres of 100% alcohol. Finland = 100 (index)

Source: Statistical Yearbook of Finland 2002, Table 656

We can also use an index to follow the development of alcohol consumption over time. The example below shows the development of per capita alcohol consumption from 1990 to 2000. In France, Finland and Sweden, consumption has decreased (the index is less than 100), in the UK and Ireland consumption had increased (the index is over 100)

Per capital alcohol consumption in 1990 and 2000 in selected European countries, litres of 100% alcohol. 1990 = 100 (index)