Consumer price index: documentation of statistics
The documentation of the statistics describes how the statistics were compiled and what methods were used in the compilation. The data help interpret the figures of the statistics and evaluate their reliability and comparability. The quality report is based on the EU's SIMS model. The documentation also contains change releases describing changes in the statistics and possible specifying methodological descriptions.
If you are looking for statistical figures for these statistics, go to the statistics page: Consumer price index
Quality report
Data description (SIMS 3.1)
The consumer price index describes the price development of goods and services purchased by households in Finland and it is used as a general measure of inflation. The point figures of the Cost-of-living Index and the Harmonised Index of Consumer Prices are published in connection with the statistics. The latter allows comparisons of inflation between EU countries.
Price data are collected for the statistics and price data produced by other statistics are also used. Data are published monthly.
Sector coverage (SIMS 3.3)
The Consumer Price Index covers households’ individual consumption expenditure excluding narcotics, prostitution and financial intermediation services indirectly measured (FISIM). The Harmonised Index of Consumer Prices does not include owner-occupancy, interests on consumption and other credits, fire insurance on owner-occupied dwellings or the vehicle tax. The coverage of the Harmonised Index of Consumer Prices is about 85 per cent of the national Consumer Price Index.
Statistical unit (SIMS 3.5)
The following statistical units are used in the Consumer Price Index: commodity which refer to tangible or intangible instruments that directly (consumables) or indirectly (capital goods) satisfy people's needs and outlets which are a store, an enterprise, a government authority or other similar information provider whose prices of products or services is collected.
Statistical population (SIMS 3.6)
The population of Consumer Price Index are households and their individual consumption expenditure as well as the monitoring of price development of commodities belonging to expenditure.
Households cover all citizens of Finland regardless of nationality and right of residence. Households’ individual consumption expenditure refers to the part of consumption expenditure that occurred in the economic territory of Finland within a reference period.
Reference area (SIMS 3.7)
The Consumer Price Index is published for the whole country. Data collection applies a modified version of NUTS2 with a more suitable regional classification: Uusimaa, Southern Finland, Eastern Finland, Western Finland, Northern Finland and Whole Country.
Time coverage (SIMS 3.8)
Cost-of-living Indices are from January 1921 to December 1957. The Cost-of-living Index series has been chained backwards to 1886. Nowadays, the Cost-of-Living Index series are carried forward monthly with the monthly change figure of the consumer price index.
The Consumer Price Index series starts from 1972 and is updated monthly.
Harmonised Index of Consumer Prices is from January 2005, and has been chained backwards to 1996.
Base period (SIMS 3.9)
The base period for Consumer Price Index, Harmonised Index of Consumer Prices and Harmonised Index of Consumer Prices at Constant Taxes series is 2025.
Unit of measure (SIMS 4)
The changes in prices are published with following units of measure: point figure, annual change (%), monthly change (%), annual impact (%-units), monthly impact (%-units).
The weight structure is published as permilles.
Prices are collected as euros with the exactness of two decimals.
Reference period (SIMS 5)
The reference period is December of the previous year, to which the index of the statistical month is compared.
Classifications (SIMS 3.2)
The Consumer Price Indices use the Classification of Individual Consumption by Purpose (COICOP) which is based on a UN classification. From the COICOP classification a harmonised version is formed for EU Member States, COICOP2018 (European Classification of Individual Consumption According to Purpose), which has been specified for certain categories.
Concepts and definitions (SIMS 3.4)
Annual change
Annual change is the relative change of the index in comparison with the corresponding time period one year ago (e.g. annual change of total index of consumer prices, i.e. inflation).
Base index
In the base index the price of the calculation period is always compared with the base period. In the base index weights are usually changed less often than yearly, for example, at intervals of five years.
Chain index
In the chain index the comparison takes place always between successive calculation periods. In the chain index the change in two calculation periods is used to take forward the index point figure of the desired base period. In the chain index the weights are changed in principle in each calculation period. At times the chain index is also mentioned in such cases where the comparison period is retained fixed in comparisons within the year, but the comparison period and the weight structure of the index is changed whenever the year changes.
Consumer price
The real price paid by consumers for a good or service (including taxes, in retail trade).
Consumer price statistics
A monthly release made on the Consumer Price index material, which contains average prices for certain daily consumer goods and some other simple commodities by major region.
Effect list of price changes
The list that shows the changes of commodities and/or aggregate level indices and the effects of the changes on the total index. The review periods are changes from the previous month, from the previous year's December and from the previous year to the review period. Available from the official Consumer Price Index monthly.
Index
An index is a ratio describing the relative change in a variable (e.g. price, volume or value) compared to a certain base period (e.g. one year). The index point figure for each point in time tells what percentage the given examined variable is of its respective value or volume at the base point in time. The mean of the index point figures for the base period is 100.
Index formula
Index formula is a mathematical function by means of which an individual key figure describing change is calculated from observation values (e.g. Fischer, Laspeyres and Paasche index formulas).
Monthly change
Monthly change is the relative change in the index from a time period one month earlier. The change is usually expressed as a percentage.
Point figure
Point figure is a change quantity used in price indices, which expresses the price, average price or index of the comparison period relative to the price, average price or index of the base period. The point figure of the base period is usually denoted by the number hundred. For example, if the point figure for a commodity at a certain point in time is 105.3, it means that the price of that commodity has risen by 5.3 per cent from the base period.
Special index
A "tailored" index made to customer order, where the commodities and weight structure are defined by the customer. The weights used in the index can be either Statistics Finland's or the customer's own weights.
Total index
Total index is the index calculated as a weighted average from all the sub-series belonging to the description area of the index. Total index can be calculated as a weighted index of detailed price index series describing different commodity groups.
Weight structure
Describes what meaning each sub-index (commodity, employee group, etc.) belonging to the index has for total index.
Institutional mandate (SIMS 6)
The compilation of statistics is guided by the Statistics Act. The Statistics Act contains provisions on collection of data, processing of data and the obligation to provide data. Besides the Statistics Act, the General Data Protection Regulation, the Data Protection Act and the Act on the Openness of Government Activities are applied to processing of data when producing statistics.
Statistics Finland compiles statistics in line with the EU’s regulations applicable to statistics, which steer the statistical agencies of all EU Member States.
Further information: Statistical legislation
Legal acts and other agreements (SIMS 6.1)
The compilation of statistics is guided by the Statistics Act. The Statistics Act contains provisions on collection of data, processing of data and the obligation to provide data. Besides the Statistics Act, the Data Protection Act and the Act on the Openness of Government Activities are applied to processing of data when producing statistics.
Statistics Finland compiles statistics in line with the EU’s regulations applicable to statistics, which steer the statistical agencies of all EU Member States.
Further information: Statistical legislation
Data sharing (SIMS 6.2)
Consumer Price Index is published every month at Statistics Finland's websites. The web pages of Consumer Price Index can be found from Statistics Finland’s website. Longer time series from statistics are also available in the StatFin online service.
As the year changes, the weight structure of Consumer Price Index is published and in the review the most essential changes to price collection and calculation methods made in change of statistical year are described.
Harmonised Index of Consumer Prices is delivered to EU twice a month: a flash estimate and final index series. Harmonised Index of Consumer Prices at Constant Taxes is delivered once a month: only the final data are sent to EU. In addition to HICP and HICP-CT deliveries, commodity weight structures (preliminary and final data) and country weight structures as well as administered price weight shares from total consumption are delivered to EU in the beginning of each new statistical year.
The changes made in the change of the statistical year are updated to metadatasystems of EU (ESS metadatahandler) and IMF (ICS, integrated correspondence system).
The Classification of Individual Consumption by Purpose (COICOP) with new and removed commodities is updated to Statistics Finland’s classification system as the year changes.
Source data (SIMS 18.1)
Each mid-month, Statistics Finland's interviewers collect prices from approximately 1,700 outlets for the Consumer Price Index. Additionally, some of the prices are collected from other sources such as scanner data provided by companies, administrative sources, or other statistics.
Consumer Price Index is based on sample survey where scanner data is not available.The sample consists of two separate parts, the Product sample (the products included in the index ) and the Outlet sample (the outlets from which product information is collected).
Until 2012, updating of the product sample took place in connection with the base year revision at intervals of approximately five years. Since 2013, the product sample has been updated annually. The product sample is formed utilising statistics on retail trade sales, the Household Budget Survey and other sources.
The outlets in the outlet sample of the Consumer Price Index are selected in a way that they represent as well as possible the structure of retail trade in both retail chains and the size of the stores. The regional differences are also taken into account if possible. Statistics Finland’s Register of Enterprises and Establishments is used as the sampling frame. The outlets included in the collection are picked from the frame randomly so that different size categories are represented. In addition to turnover, the knowledge of Statistics Finland’s interviewers of the local area is utilised in the sampling, which can help include new important outlets in data collection even if they are not yet visible in the Business Register.
Frequency of data collection (SIMS 18.2)
The data are mainly collected monthly, in some price items twice a month or more often (scanner data).
Data collection (SIMS 18.3)
Data are collected either by statistical interviewers across Finland or as centralised data collection at Statistics Finland. Scanner data are part of centralised data collection. They are delivered as line transfers from the source system to Statistics Finland.
Data validation (SIMS 18.4)
The collected data are checked by the Consumer Price Index team with automatic procedures. Where necessary, a statistical expert verifies the price data of individual commodities on the checklist. Validation methods and procedures are based on international guidelines and EU Regulations.
Data compilation (SIMS 18.5)
Erroneous data are as a rule corrected manually. Centralised collected data are validated already when collecting them, so they need not be corrected afterwards.
Missing data are imputed with agreed procedures. Typically missing price data are imputed with the price development of other products/services in the same category value, the so-called category-average method.
Scanner data are genuinely collected transaction data so they need not be corrected afterwards. Only erroneously classified products are corrected in line with the COICOP classification.
User needs (SIMS 12.1)
The main users of the Consumer Price Index are the central government, Ministry of Finance, research institutes, financial and insurance sector and other private sector and ordinary people. The main user of the HICP is the EU in the comparison of Member States and ECB, national banks, the Bank of Finland in assessing price stability.
User satisfaction (SIMS 12.2)
Statistics Finland has an working group of consumers' statistics on economic trends comprising representatives of the Ministry of Finance, the financial sector and research institutes. The working group convenes two times per year.
Overall accuracy (SIMS 13.1)
The compilation on Consumer Price Indices is always based on a sample of products and services available to consumers. Certain particular sources of bias in the Consumer Price Index have been recognised in the so-called Boskin's report which are e.g. substitution bias, new product bias, outlet substitution bias and quality change bias.
For a more detailed description of these, see the Consumer Price Index Handbook for users, pp. 16 to 17 on web page https://urn.fi/URN:ISBN:978–952–244–566–7
The statistics published by the Consumer Price Index are based on multiple data sources and sampling systems. In the calculation solutions, the randomness caused by sampling is reduced by the fact that the statistics are based on a panel design. This procedure ensures that the price change estimates are very precise in a sampling technical respect.
Due to the large number of samples and sampling designs differing from each other, it is difficult to assess the statistical standard error for the index. The index is generally assessed to be so exact that it is statistically sensible to publish its results at the present accuracy of two decimal places.
Quality assurance (SIMS 11.1)
Quality management requires comprehensive guidance of activities. The European Statistics Code of Practice forms the basis for the common quality system of the European Statistical System.
The Code of Practice is based on 16 principles that concern statistical authorities' independence, accountability and the quality of the processes and data to be published.
The principles are in line with the Fundamental Principles of Official Statistics approved by the United Nations Statistics Commission and are supplementary to them. The quality criteria of Official Statistics of Finland are compatible with the European Statistics Code of Practice.
Further information:
Quality assessment (SIMS 11.2)
Quality controlling and quality evaluation is done according to EU regulation which can be found at https://ec.europa.eu/eurostat/statistics-explained/index.php/HICP_methodology
The Harmonised Index of Consumer Prices methodological manual (2024) can be found at https://ec.europa.eu/eurostat/documents/3859598/9479325/KS-GQ-17-015-EN-N.pdf.
The ILO Manual of Consumer Price Index (Consumer Price Index Manual: Theory and Practice, 2020) can be found at https://www.ilo.org/publications/consumer-price-index-manual-concepts-and-methods-2020.
Data revision - policy (SIMS 17.1)
Revisions – i.e. improvements in the accuracy of statistical data already published – are a normal feature of statistical production and result in improved quality of statistics. The principle is that statistical data are based on the best available data and information concerning the statistical phenomenon. On the other hand, the revisions are communicated as transparently as possible in advance. Advance communication ensures that the users can prepare for the data revisions.
The reason why data in statistical releases become revised is often caused by the data becoming supplemented. Then the new, revised statistical figure is based on a wider information basis and describes the phenomenon more accurately than before.
Revisions of statistical data may also be caused by the calculation method used, such as annual benchmarking or updating of weight structures. Changes of base years and used classifications may also cause revisions to data.
Timeliness (SIMS 14.1)
The prices are collected on the 10th to 20th of the statistical month or concerning the whole month and are published on the 14th of the following month. Preliminary data are delivered to the EU on a monthly basis at the turn of the month.
The delay from the last day of the statistical month to the release of first preliminary results is 7 to 8 days.
The delay from the last day of the statistical month to the release final results is 14 days, except the index for January when it is 19 days.
Punctuality (SIMS 14.2)
The Consumer Price Index is exact because EU legislation obligates to produce the information on the schedule confirmed by EU. The delay can be 15 days at most.
Comparability - geographical (SIMS 15.1)
Harmonised Index of Consumer Prices is compiled according to EU guidance in a way that the data compiled in different Member States are comparable.
Comparability - over time (SIMS 15.2)
When the commodity basket or classification of Consumer Price Index is changed, the statistical time series are linked to each other by chaining. With chaining procedure, long time series can be formed about general inflation. The oldest official inflation series begins from 1914. This series has been chained to begin from 1886 afterwards.
Coherence – cross domain (SIMS 15.3)
Other public authorities, such as The Finnish Competition and Consumer Authority (FCCA) and Centre for Consumer Society Research, as well as private companies also produce price comparison information. Because of the different methods and more incomplete samples, other price comparison information may vary from the price development from Consumer Price Index. The price comparisons are, however, often very close to each other.
Coherence - national accounts (SIMS 15.3.2)
The Consumer Price Index is part of well-established macroeconomical statistical production. Its figures are used, for example, by the National Account as deflators for private consumption. Moreover, the Consumer Price Index utilizes the consumption expenditures which are produced by the National Account. It follows, that from a technical reason, CPI's series and national account's consumption time series are rather connected.
Release calendar (SIMS 8.1)
Statistics Finland publishes new statistical data at 8 am on weekdays in its web service. The release times of statistics are given in advance in the release calendar available in the web service. The data become public after they have been updated in the web service.
Further information: Publication principles for statistics at Statistics Finland
Release calendar access (SIMS 8.2)
Statistics Finland's release calendar Future publications
Future publications of the statistics can be found on the page of the statistics at: Future publications of the statistics
User access (SIMS 8.3)
The data are released to all users at the same time. Statistical data may be processed at Statistics Finland and information on them may be given before release only by persons involved in the production of the statistics concerned or who need the data of the statistics concerned in their own work before the data are published.
Further information: Publication principles for statistics
Unless otherwise specifically stated in connection with the product, data or service concerned, Statistics Finland is the producer and copyright owner of the data.
Further information: The terms of use for statistical data
Frequency of dissemination (SIMS 9)
Consumer Price Index is published monthly. Harmonised Index of Consumer Prices is published two times a month: flash estimate and final at Eurostat and Statistics Finlands' websites, respectively.
News release (SIMS 10.1)
The release is published monthly on the home page of the statistics
Online database (SIMS 10.3)
The database tables of the statistics can be found in the StatFin database.
Eurostat's database concerning the Harmonised Indices of Consumer Prices HICP: https://ec.europa.eu/eurostat/web/hicp/data/database
The ECB’s HICP database service: https://www.ecb.europa.eu/stats/macroeconomic_and_sectoral/hicp/html/index.en.html
The UN's CPI database service: https://w3.unece.org/PXWeb/en/DataMap?IndicatorCode=1
Micro-data access (SIMS 10.4)
Researchers have access to the following unit-level data sources: Statistics Finland's TAIKA research data contain unit-level data for the Consumer Price Index for 1997 to 2018 and data file FIRM_CPI Unit-level data for the Consumer Price Index for 1997 to 2018 (YA272).
Individual products or services and outlets from which price data have been collected are described in the data file only with identification codes. This is made to ensure the protection of unit-level data.
Unit-level data are not released to other authorities.
Documentation on methodology (SIMS 10.6)
- Methodological document of the statistics: CONSUMER PRICE INDEX 2015=100 HANDBOOK FOR USERS https://urn.fi/URN:ISBN:978–952–244–566–7
- Harmonised Index of Consumer Prices manual (2024): https://ec.europa.eu/eurostat/documents/3859598/9479325/KS-GQ-17-015-EN-N.pdf
- Consumer Price Index manual (2020): https://www.ilo.org/publications/consumer-price-index-manual-concepts-and-methods-2020
Confidentiality - policy (SIMS 7.1)
The data protection of data collected for statistical purposes is guaranteed. The compilation of statistics is guided by the Statistics Act. Alongside the Statistics Act, the EU’s General Data Protection Regulation (eur-lex.europa.eu) and the Finnish Data Protection Act (Finlex.fi) are applied to the processing of personal data. Provisions on the confidentiality of data collected for statistical purposes are laid down in the Act on the Openness of Government Activities (Finlex.fi).
The data are processed only by persons who need the data in their work. The use of data is restricted by usage rights. All persons employed by Statistics Finland have signed a pledge of secrecy, where they have obliged to keep secret the data prescribed as confidential by virtue of the Statistics Act or the Act on the Openness of Government Activities.
Further information: Data protection
Confidentiality - data treatment (SIMS 7.2)
When publishing and tabulating the data, the threshold rule (data from at least three enterprises) is primarily used. The dominance rule is in use so that the permission to publish the data has been asked from the enterprise dominating a commodity group.