15.3.2023 valid documentation

Basic data of the statistics

Data description

The Trend Indicator of Output endeavours to forecast the monthly development of the national economy. It contains volume time series since January 1996. The volume of output refers to value added by industry. Value added is calculated as the difference between output and intermediate consumption. The source data of the statistics are mainly indicators of the development of output – intermediate consumption for the latest periods has been estimated. The published industry levels are whole economy total, primary production, secondary production and services. The data are in the form of an index so that the average value for the year 2015 is one hundred. In the chaining of the volume series the base year is always the previous year. The data have been calculated as original data and working day adjusted for the whole national economy and for three main industries. In addition, a seasonally adjusted series and a trend series are calculated for the whole economy. 

The GDP flash estimate calculated on the basis of the data of the Trend Indicator is also published quarterly. 

Statistical population

The Trend Indicator of Output is combined with source statistics covering all economic activities. 

Statistical unit

The Trend Indicator of Output is mainly based on statistics produced by other statistics. 

For manufacturing and private services, the value data sources are primarily the turnover indices and the volume indices of industry and services, and for public services the preliminary data of the wage and salary indices. Producer price indices and indices of wage and salary earnings are utilised as price data. Those acting as source data for primary production are unit volume data on volumes of milk received by dairies, slaughterhouse statistics, crop production statistics, data on market fellings, and unit price data corresponding with these unit volume data. 

Unit of measure

The measurement units are index point figures and change percentages. 

Base period

The data are in the form of an index so that the average value for the year 2015 is one hundred. 

Reference period

he reference period is a month. The Trend Indicator of Output is published at a lag of around six weeks from the end of the reference month. 

In connection with the monthly Trend Indicator, a so-called flash estimate on the development of GDP is published four times a year based on the Trend Indicator data. The reference period is then a quarter. 

Reference area

The Trend Indicator of Output is published on the level of the whole country. 

The source data may contain turnover data, which also include activities outside the borders of Finland. 

As regards turnover indices, the data of the sales inquiry may not fully cover the definition of global production in national accounts. 

Sector coverage

The publication includes time series for three main industries (primary production, secondary production and services) and for the whole economy. The source data used in the calculation cover most of the data used in quarterly national accounts. The calculation is performed at the 2-digit level of the classification of industries. Intermediate consumption is not estimated separately, but its volume is assumed to follow the development of the volume of output. 

Time coverage

The Trend Indicator of Output covers monthly data starting from 1995. 

Frequency of dissemination

The data of the statistics are published monthly on Statistics Finland's website. 


Adjustment for seasonal variation

Seasonal adjustment means the estimation of seasonal variation and the elimination of its impact from a time series. The obtained result is a seasonally adjusted time series. The trend of a time series is obtained when both seasonal variation and irregular random variation are eliminated from a time series. Trading or working day adjusted series are in turn obtained when the factors caused by the variation in the number of trading days or weekdays is eliminated from the observation of the original time series. The Tramo/Seats method is used for the seasonal adjustment of time series at Statistics Finland. In the Tramo/Seats method, preadjustment is based on a regression model (which allows for outlying observations, public holidays and the weekday structure) and the seasonal adjustment proper on an ARIMA model constructed for the time series.

Adjustment for working days

An adjustment for working days takes into account influences arising from the number of working days. This means giving consideration to lengths of months, numbers of weekdays and public holidays. Figures adjusted for working days are published for industries where variation in the number of working days has a significant impact on a time series. Compared to adjustment for trading days, adjustment for working days does not take into account the effect of different days of the week.


Trend describes the long-term development in a time series. A trend series has been adjusted for seasonal and random variations, so that the effects of e.g. weather conditions or short-term labour disputes do not show in it. By contrast, permanent changes, such as growth in demand due to changed taxation, will show in a trend. The direction indicated by the end of a trend should be interpreted with caution. The latter part of a trend indicator may change once it has been updated with data for subsequent months.

Accuracy, reliability and timeliness

Overall accuracy

The accuracy of the Trend Indicator of Output can be assessed with the help of the revision table presented in connection with the publication. Revisions are caused either by revisions to the source data or benchmarking against quarterly national accounts. Because the time series is fully recalculated every round, revisions to old years are also possible, if, for example, the levels of annual national accounts change and the changes are carried over to the quarterly national accounts through benchmarking and further to the Trend Indicator of Output. 


The Trend Indicator of Output is published some 45 days from the end of the statistical reference month. 


There is no delay in the release of the Trend Indicator of Output. The data have been published on the day set in the calendar. 


Comparability - geographical

European definitions according to the STS Regulation are used in the production of the statistics, so the data of the statistics are internationally comparable and cover the whole of Finland. 

Comparability - over time

The time series of the Trend Indicator of Output are congruent with the time series of quarterly national accounts concerning value added with respect to the same point in time. 

Coherence - cross domain

The calculation of the Trend Indicator of Output is based on output indicators. Because intermediate consumption, taxes on products and subsidies on products are not separately estimated, the Trend Indicator of Output does not directly measure the development of gross domestic product. However, historical time series correspond to value added in quarterly national accounts. The flash estimate aims to estimate taxes on products and subsidies on products. 

Due to the revision method, the series concerning sub-industries of the Trend Indicator of Output are not directly comparable with the source statistics. 

Source data and data collections

Source data

The Trend Indicator of Output is mainly a set of statistics compiled from other statistics. Data on primary production are collected from the data of the Natural Resources Institute Finland's agricultural and forestry statistics. For manufacturing and services, the volume index of industrial output, the volume index of services and the turnover of trade are utilised. In the calculation of the output of public sector industries, as well as the household sector and non-profit institutions, the Tax Administration's register of self-assessed taxes is partly utilised as regards the wages and salaries sums. 

Data collection

The statistics are mostly comprised of other statistics that are supplied within Statistics Finland. 

Statistics Finland has agreed with the Tax Administration that the Tax Administration delivers the data on self-assessed taxes to Statistics Finland monthly on an agreed date. 

The data on primary production are drawn from the Natural Resources Institute Finland's statistical database. 

Frequency of data collection

The source data are supplied monthly. 


Data compilation

The methodological description can be found on the home page of the statistics. 

In short, the process is as follows: 

The Trend Indicator of Output is based on output indicators. The indicator series are saved according to the classifications of the national accounts into a database, after which the series are benchmarked to the quarterly national accounts data of the corresponding accuracy. The method is the proportional Denton method. 

The newest data for which no corresponding period can be found from quarterly national accounts are extrapolated using either with the BI ratio or with the so-called annual overlap change, depending on the source data. In addition to benchmarked output indicators, benchmarked indicators for intermediate consumption are formed, which match quarterly accounts data in terms of history and which are assumed to develop at the same pace as the volume development of output. 

Data at current prices are deflated to the previous year's average prices. Figures at the previous year's average prices are chained with the annual overlap method.  

In addition to chain-linked series, seasonally adjusted series and series adjusted for working days are also published. 

Seasonal adjustment is a statistical method used to process time series. The method is used to remove variation occurring fairly regularly within a year from the data. The Tramo/Seats method and JDemetra+ software are used in the statistics. In addition, seasonal adjustment is based on the ESS Guidelines on Seasonal Adjustment. 

Data validation

The source data for manufacturing and services are validated monthly with the unit that supplied the source data. 

Documentation on methodology

The methodological description of the Trend Indicator of Output can be found on the home page of the statistics. The description contains a detailed report on the benchmarking, extrapolation, chaining and seasonal adjustment methods used in the compilation of the statistics.

Principles and outlines

Contact organisation

Statistics Finland

Contact organisation unit

Economic Statistics

Legal acts and other agreements

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 

Confidentiality - policy

The data protection of data collected for statistical purposes is guaranteed in accordance with the requirements of the Statistics Act (280/2004), the Act on the Openness of Government Activities (621/1999), the EU's General Data Protection Regulation (EU) 2016/679 and the Data Protection Act (1050/2018). The data materials are protected at all stages of processing with the necessary physical and technical solutions. Statistics Finland has compiled detailed directions and instructions for confidential processing of the data. Employees have access only to the data essential for their duties. The premises where unit-level data are processed are not accessible to outsiders. Members of the personnel have signed a pledge of secrecy upon entering the service. Violation of data protection is punishable. 

Further information: Data protection | Statistics Finland (stat.fi) 

Confidentiality - data treatment

The data are calculated at the 2-digit level but aggregated to the level of three main industries in the publication. 

Release policy

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 are public after they have been updated in the web service. 

Further information: Publication principles for statistics at Statistics Finland 

Data sharing

The quarterly flash estimate is delivered to Eurostat as part of the EU's GDP aggregates. 

Accessibility and clarity

Statistical data are published as database tables in the StatFin database. The database is the primary publishing site of data, and new data are updated first there. When releasing statistical data, existing database tables can be updated with new data or completely new database tables can be published.   

In addition to statistical data published in the StatFin database, a release on the key data is usually published in the web service. If the release contains data concerning several reference periods (e.g. monthly and annual data), a review bringing together these data is published in the web service. Database tables updated at the time of publication are listed both in the release and in the review. In some cases, statistical data can also be published as mere database releases in the StatFin database. No release or review is published in connection with these database releases. 

Releases and database tables are published in three languages, in Finnish, Swedish and English. The language versions of releases may have more limited content than in Finnish.   

Information about changes in the publication schedules of releases and database tables and about corrections are given as change releases in the web service. 

The data of the quarterly flash estimate can also be found in Eurostat's release calendar. 

Micro-data access

The Trend Indicator of Output is mainly compiled from other statistics whose micro level data are not available as a rule. 

Data revision - policy

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. 

Seasonally adjusted data in statistics on economic trends become revised because of the calculation method used. Additional information on a new time series observation is exploited in model-based calculation methods and this is reflected as changes in previous releases. Revisions of the latest figures to be seasonally adjusted are elaborated on in the releases and quality reports of statistics. 

A summary table of the revisions that have taken place is also published in connection with key statistics on economic trends and some annual statistics. The table shows how the data for the statistical reference periods have changed between the first and the most recent statistical release. 


The Trend Indicator of Output provides fast trend data for analysing the state of the economy. The calculation data of the statistics are also utilised in more comprehensive compilation of quarterly national accounts. The data are used for verifying the state of the economy and forecasting the development of the economy. 

User needs

Economic research institutes, banks and consulting firms prepare situation reports and forecasts on economic development utilising the data of the Trend Indicator of Output and quarterly national accounts.  

Quality assessment

Official Statistics of Finland (OSF) are a comprehensive collection of statistics describing the development and state of society. They comprise nearly 300 sets of statistics on 26 different topics. The producers of Official Statistics of Finland have approved a common quality assurance in which they commit to common quality criteria and quality assurance measures. 

The quality criteria of Official Statistics of Finland are compatible with the European Statistics Code of Practice. The good practices followed in the statistics are presented in Statistics Finland's Quality Guidelines for Official Statistics handbook. 

Quality assurance

Quality management requires comprehensive guidance of activities. The quality management framework of the field of statistics is the European Statistics Code of Practice (CoP). The frameworks complement each other. The quality criteria of Official Statistics of Finland are also compatible with the European Statistics Code of Practice. 

Further information: Quality management | Statistics Finland (stat.fi) 

User access

Data are released to all users at the same time. Statistical data may only be handled 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 separately stated in connection with the product, data or service concerned, Statistics Finland is the producer of the data and the owner of the copyright. The terms of use for statistical data. 

Revisions in statistics

Statistical experts

Antti Kosunen
Senior Statistician
029 551 3613

The documentation released before 5.4.2022 can be found on the archive pages of the statistics.

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