Laspeyreslähestymistapaan

Laspeyreslähestymistapaan, often referred to as the Laspeyres index, is a method for calculating a price index. It is named after the German economist Étienne Laspeyres. The core principle of the Laspeyres index is to use a fixed basket of goods and services from a base period to measure price changes over time. This means that the quantities of the items included in the index remain constant for each period being compared.

When calculating a Laspeyres index, the prices of goods and services in the current period are multiplied by the quantities consumed in the base period. These values are then summed up and compared to the total cost of the same basket of goods and services in the base period. The resulting ratio, often expressed as a percentage, indicates the extent to which prices have risen or fallen relative to the base period.

The primary advantage of the Laspeyres index is its simplicity and ease of calculation. It is widely used in constructing consumer price indexes (CPIs) and other economic statistics because it provides a straightforward measure of how the cost of a representative set of goods has changed. However, a significant limitation is that it does not account for changes in consumption patterns that may occur due to price shifts. Consumers may substitute cheaper goods for more expensive ones, a phenomenon that the Laspeyres index, with its fixed quantities, fails to capture. This can lead to an overstatement of inflation, a bias known as the substitution bias.