Harmonised consumer price index (HICP) 2025=100

What does the survey entail?

Purpose

The monthly publication of price changes in consumer goods and services. The price changes are shown in the form of a price index. These indices are compiled in a similar way across all European Union (EU) countries. The European price indices therefore provide a good comparison of price changes between the various member states. The annual rate of change is calculated as the percentage change of the HICP in a particular month compared to the same month in the previous year. This annual rate of change is known as inflation. On the basis of these data, Statistics Netherlands (CBS) also calculates the HICP at constant tax rates (HICP-CT). The effect of changes in product-related tax rates (e.g. VAT and excise duty on alcohol and tobacco products) has been removed from this series. The HICP-CT answers the question: how would prices have changed if the tax rates had remained the same?

Target population

Consumer goods and services purchased by consumers on Dutch territory.

Statistical unit

Consumer goods and services.

First year of survey

1996

Frequency

Monthly

Publication strategy

Provisional figures for each reporting month are published in a flash estimate. Based on a request submitted by Eurostat, the regular HICP results are only defined as provisional if - at the moment of publication - it is evident that the data is incomplete and/or will be subject to an update in the next few months. In most cases, all requested information regarding consumer prices is available at CBS when the regular results are published and later adjustments will not be required. Occasionally, specific information may not be available on time. In such cases, the results can be adjusted at a later stage. This means that HICP results can be updated at any time, even if they had no provisional status in the preceding month.

How is the survey conducted?

Type of survey

The survey is based on monthly price data collected from businesses and institutions that supply goods and services to consumers.

Data collection method

CBS increasingly uses transaction data (such as scanner data from supermarkets and other retail chains) and register data to monitor prices for the HICP. Web scrapers and automated online applications that collect prices automatically are also used. In addition, CBS conducts online surveys and prices are also monitored manually online.

Sources and respondents

In order to collect data on prices for the HICP, CBS consults businesses, institutions, associations and government bodies. CBS mainly receives aggregated source data that does not contain personal data. However, CBS does consult sources containing linked personal data for a number of price measurements:

• Online surveys can be sent to sole proprietorships, for example lawyers or painters;
• For rents, the Basisregistratie Kadaster (BRK) and the Eigendomsverhouding vastgoed (koop-huur) of the Netherlands’ Cadastre are used as source data. In addition, the Inkomensafhankelijke huurverhoging of the Tax Administration of the Netherlands is used. For the energy labels and energy indices of homes, data is obtained from the Netherlands Enterprise Agency (RVO);
• The Childcare benefit (Kinderopvangtoeslag - WKO) of The Tax Administration is used to measure price changes in childcare services.
• Data from the Central Administration Office (CAK) regarding care - for which users are required to pay a personal contribution - is used to measure price changes in nursing homes and domiciliary care.

Scope of sample survey

Every month, CBS collects data on prices from datasets including transaction prices and register data. In addition, with the help of automated online applications, web scrapers, online surveys and manual data collection via the internet, approximately 7,000 prices for around 650 different goods and services are recorded, with around 2,500 respondents.

Checking and correction methods

Once the data is received, CBS checks it for completeness and plausibility. If data is incomplete or incorrect, the respondent is asked to provide additional information. If no response is forthcoming, the relevant data is imputed (the necessary information is estimated on the basis of other data collected). If a clearly defined product undergoes changes, differences in the quality of the old and the new versions of the product can be taken into account.

Weighting

A package of goods and services is created in order to measure price changes. Each product or service in this package is assigned a weighting that indicates how important the product or service is in the consumption pattern of consumers in the Netherlands. Data on consumer spending data from the national accounts is used to determine the weighting of the various goods and services in the HICP. In addition, budget surveys and other external sources are used. The HICP is a monetary index with particular focus on comparability between countries. Therefore, the package of goods and services used for the HICP varies from the CPI package. The HICP includes private consumption of people visiting the Netherlands, but price changes affecting Dutch consumers abroad are not taken into account. Other differences include home ownership, consumer-related taxes and membership fees for sports clubs. The weightings for the product groups in the HICP are adjusted and published annually in January.

Quality of the results

Accuracy

Monitoring the prices of a very broad and diverse range of products on a monthly basis in different sales channels throughout the country maximises the accuracy and representativeness of the HICP. However, it is impossible to calculate its degree of accuracy. The accuracy of price changes for a specific product category is generally lower than for the total consumption package. Inaccuracies may arise at various points in the production process:

• when sampling respondents
• when selection of representative items and estimation of quality differences
• when monitoring prices
• when determining the weighting factors
• as a result of non-response.

Comparability over time

Price changes are measured by including the prices of a broad range of products that have been surveyed over two consecutive months at the same retail outlet. The reference base is adjusted annually in January. At that moment, a new package of products and services is introduced, and the weightings are also updated. The data are therefore not the same year on year, but are comparable.

Quality strategy

The data is checked for internal consistencies and completeness. Wherever necessary, action is taken to verify the data. If the data is correct, the price indices are calculated and the results are verified and validated. The results are validated by other staff members than those who compile the figures. If it is found that incorrect data has been used to compile the price indices, there is a protocol to decide whether the results need to be revised. If the results are not revised, the price index will be brought to the right level in the subsequent month.