Purpose and brief description
The consumer price index is an economic indicator whose main task is to objectively reflect the price evolution over time for a basket of goods and services purchased by households and considered representative of their consumer habits. The index does not necessarily measure the price level of this basket for a specific period of time, but rather the fluctuation between two periods, the first one acting as basis for comparison. Moreover, this difference in the price level is not measured in absolute, but in relative terms. The consumer price index can be determined as a hundred times the ratio between the observed prices of a range of goods and services at a given time and the prices of the same goods and services, observed under the same circumstances during the reference period, chosen as basis for comparison. Price observations always take place in the same regions.
Since 2014, the consumer price index has been a chain index in which the weighting reference period is regularly shifted and prices and quantities are no longer compared between the current period and a fixed reference period, but the current period is compared with an intermediate period. By multiplying these short-term indices, and so creating a chain, we get a long-term series with a fixed reference period.
Belgian private households
Data collection method and possible sampling
Survey technique applied using a computer, based on the use of electronic questionnaires and laptops.
Timing of publication
The results are available on the penultimate working day of the reference period.
Weight (CPI): The weight represents the importance of the goods and services included in the CPI in the total expenditure patterns of the households. Weights are determined based on the household budget survey.
Consumer price index (CPI): The consumer price index is an economic indicator whose main task is to objectively reflect the price evolution over time for a basket of goods and services purchased by households and considered representative of their consumer habits.
Health index: The health index is derived from the consumer price index and has been published since January 1994. The current value of this index is determined by removing a number of products from the consumer price index product basket, in particular alcoholic beverages (bought in a shop or consumed in a bar), tobacco products and motor fuels except for LPG.
Inflation: Inflation is defined as the ratio between the value of the consumer price index of a given month and the index of the same month the year before. Therefore, inflation measures the rhythm of the evolution of the overall price level.
Consumer price index without petroleum products: This index is calculated by removing the following products from the consumer price index: butane, propane, liquid fuels and motor fuels.
Consumer price index without energy products: This index is calculated by removing the following products from the consumer price index: electricity, natural gas, butane, propane, liquid fuels, solid fuels and motor fuels.
Smoothed index: The smoothed index is the arithmetic mean of the health index of the last 4 months. The smoothed index is used as basis for the indexation of retirement pensions, social allowances and some wages and salaries. The indexations of public services wages and social benefits are implemented when the smoothed index exceeds a certain value, the so-called central index. When the smoothed index exceeds the central index, the benefits increase by 2 % the following month. The wages in the public sector also increase by 2 % two months after the central index was exceeded.
An effect on inflation shows the changes on the inflation rate by including this product group in the CPI calculation. The effect not only takes the weight of the product group into account, but it also takes into account whether the product group inflation is higher or lower than that of the total expenditure (overall CPI).
The contribution to inflation of a specific product group shows how much of the change in the total expenditure is due to the price variation of this product group.