Population projection: documentation of statistics

The statistics on population projection aim to describe future population development in Finland. Statistics Finland’ population projections are so-called demographic trend calculations, which calculate the future population for a given area assuming that the development that has taken place in its population in recent years continues unchanged. A by-product of projection calculations by municipality is a so-called self-sufficiency estimate, which describes how the population would develop if there was no migration.

The basic population in the population projection prepared in 2024 has been population by municipality at the end of 2023 by 1-year age group according to gender. The projection was calculated by municipality and the figures for regions and the whole country were derived from municipality data by summing. The projection data can also be printed out using any other regional division as long as it is based on municipalities. In addition to data on population numbers, data are also available on the numbers of births, deaths and migrants according to the projection and the coefficients used in calculating the projection.

There are two calculations of the projection:

• A calculation including migration, where account is taken of the effect of the birth rate, mortality, inter-municipal migration and migration on population development.
• The self-sufficiency calculation expresses what the future population development would be like without migration. The calculation takes only the impact of the birth rate and mortality on population development into account. The assumptions concerning birth rate and mortality are the same as in the calculation including migration. The numbers of births are, however, different in these calculations, as migrants assume the fertility of the receiving area in the calculation including migration.

The Central Statistical Office of Finland published the first population projection concerning Finland's future population development in 1934. In 1956, the memorandum of the statistical committee set up in 1953 proposed that population projections should be compiled at regular intervals. The first projections related to the population development of the whole country. Preparation of regional projections started in the 1960s.

In 1973, the so-called population projection group established by the Prime Minister's Office published its report “On arrangement of compilation of population projections” (Prime Minister's Office publications 1973:1). In the report, population projections were defined as follows: “Population projections are calculations based on the past development of the factors influencing population development, which do not include population development planned by the compiler of the projection or expressions of intent related to regional policy.”

According to the report, population projections “indicate to decision-makers primarily what the development will lead to if social policy stays unchanged. Decision-makers have to assess the advisability of the development and consider on this basis whether the forecasts can be used as the basis for decisions on investments and measurement of activities.”

The population of the statistics is Finland's projected number of population.

The statistical unit is a person.

The unit of measure is the number of persons.

The reference period is the last day of the year (31 December).

Data are available on Finland on the level of the whole country and by various regional divisions based on the division of municipalities in Finland.

Population projections give forecasts for the number and age structure of population at the end of each projection year for the whole country, municipalities or other areas based on the division of municipalities. The projection also gives forecast numbers for births, deaths and migration.

The 2024 projection was compiled on the level of the whole country until the year 2075. It was published by region up to the year 2045. The new population projection always replaces previously compiled population projections.

Up to now, population projections have been made at three-year intervals. Population projections are compiled and published in the autumn.

Projections always involve uncertainty. The longer the projection period extends, the greater the uncertainty. Uncertainty is also greater in municipalities with a small population base.

Municipal projections should be compiled for all municipalities with the same principles. It would be impossible to treat municipalities ”individually”, and therefore there have always been and will always be cases where e.g. the calculation period of the projection coefficients has somehow been exceptional for a municipality, which causes the projection to differ from the trend development in either direction.

The projection deviations for small municipalities are primarily due to their projection coefficients not corresponding to the actual level of out-migration, in-migration, fertility or mortality. Small municipalities must be combined into larger entities in order to reduce random variation.

Until the start of the 2000s, the whole country was divided into four mortality areas in population projections. Since 2007, the number of mortality areas has been considerably higher. The number of mortality areas has been increased so that regional differences in the level can be better taken into account, because the population projection by municipality has previously had some over-mortality. In order to reduce random variation, mortality coefficients have been calculated for a longer period and mortality coefficients for the whole country have been used for certain age groups (0 to 17 and 90 to 104+).

Statistics Finland has compiled population projections by municipality at intervals of roughly three years. In the intervening years, projection calculations were made concerning the whole country based on various assumptions, e.g. the low, average and high alternative. In recent years, alternative calculations have been made mainly only as chargeable assignments, in which case the calculations have been based on the assumptions specified by the customer.

The 2024 projection extends to the year 2075. It was published by region up to the year 2045.

There is usually no delay in the statistics.

When comparing different projections, differences in the projection assumptions should be taken into account. Many municipalities prepare their own population projections, where assumptions may deviate greatly from those used in Statistics Finland’s projections. In addition to Statistics Finland, population projections concerning the whole of Finland are produced by Eurostat and the UN, for example.

Statistics Finland's population projections are long-term projections. Therefore, they do not always give a reliable picture of the number of births or deaths in the coming years, for example. Since the 1970s, the birth rate has fluctuated up and down so that the total fertility rate has varied between 1.26 (2023) and 1.87 (2010). In population projections, fertility has been kept constant at some average or initial level, because it would be impossible to guess the turning points in development. Likewise, mortality has fallen quickly at times and slowly at others. In the projections, the change coefficients for mortality have been calculated for around 20-year periods so that they would include periods of both quick and slower lowering. When comparing projections made in different years, differences in the projection assumptions should be taken into account.

In Statistics Finland's population projections the population figures for each year refer to the situation on 31 December. In the projections by Eurostat and many municipalities, the figures refer to the situation on 1 January. In the UN projections, the figures refer to the situation in the middle of the year.

Finland’s population statistics are based on the Population Information System maintained by the Digital and Population Data Services Agency (previously by the Population Register Centre and local register offices). The source data for the population projection are Statistics Finland's statistics on births, deaths and migration and statistics on population structure.

There is no actual data collection for the statistics. The data for the statistics used as source data derive from the Digital and Population Data Services Agency's Population Information System.

There is no actual data collection for the statistics. The statistics used as source data are annual statistics.

The population projection method used by Statistics Finland is a so-called demographic component model, in which the future population number and age structure are calculated by means of age group-specific birth rate, mortality and migration coefficients. The coefficients are calculated on the basis of demographic statistics for the last few years. To decrease random variation of the coefficients they are calculated for several years and in addition, municipalities are grouped into birth rate, mortality and out-migration areas.

Birth rate

To calculate the number of births, municipalities are grouped into 106 fertility areas on the basis of the total fertility rate in the years 2019 to 2023. Municipalities with a population of at least 25,000 or the number of women of fertility age is over 5,000 mainly form their own fertility areas. Municipalities with a smaller population are combined into fertility areas. Municipalities with small populations have been paired up with municipalities from anywhere in the country which have the same fertility rate. Previously the combinations were made within regions. When forming fertility areas, account has also been taken of age group-specific fertility.

Age group-specific fertility rates (women aged 14 to 50) have been calculated for the fertility areas for the years 2019 to 2023. Municipalities belonging to the same fertility area have identical fertility coefficients. In the projection the fertility rates have been kept constant throughout the projection period. For the whole country the average total fertility rate, that is, the average number of children born to each individual woman during her lifetime is 1.26.

Mortality

In order to calculate the number of deaths, 22 mortality areas have been formed. The nine municipalities with the largest populations (at least 120,000 inhabitants) form their own mortality areas and smaller municipalities have been combined into mortality areas. Municipalities have been grouped into mortality areas on the basis of age and gender-standardised mortality for the years 2018 to 2023. Therefore, the mortality area of a municipality is not determined by its geographical location.

To reduce random variation, the mortality coefficients of the whole country are used in all mortality areas for persons aged 0 to 17 and 90 to 104. Area–specific coefficients are used for persons aged 18 to 89. Age group–specific mortality rates have been calculated for the years 2019 to 2023.

The coefficients by age and gender group for the annual change in mortality were obtained for those aged under 50 by calculating how much mortality changed when comparing 1989 to 1993 with 2018 to 2023 and for those aged 50 or over by calculating how much mortality changed when comparing 1999 to 2003 with 2018 to 2023 so that the year 2022 was omitted from the comparison period. Mortality was not inflated for any age group, however.

Migration

Municipalities are divided into 102 out-migration categories according to the out-migration propensity of those aged 0 to 6 and 16 to 39 in 2019 to 2023. Municipalities with a population of at least 30,000 form their own out-migration areas. Municipalities with a smaller population are combined into out-migration areas. Municipalities with a small population have been paired up with municipalities from anywhere in the country which have the same out-migration propensity. Previously the combinations were made within regions. Age group-specific out-migration coefficients by gender for the out-migration areas were calculated on the basis of the years 2019 to 2023.

The whole country is divided into 22 major migration regions. Major migration regions have been formed around large regional centres (excl. Uusimaa and Åland). A municipality’s major migration region is determined by the regional centre or municipalities adjacent to a regional centre to which the municipality has had the most out-migration during 2019 to 2023. More migration areas have been formed into Southern Finland, because the population and migration numbers in the area require smaller regional units.

In the population projection, migration between major migration regions is calculated with migration probabilities. First, the total number of out-migrants from each major migration region is calculated by summing the number of out-migrants in the municipalities belonging to the major migration region. Then the migration probabilities are used to calculate the proportion of the out-migrants remaining in their own major migration region and the proportion of those coming to other major migration regions. The migration probabilities by gender and age group for major migration regions were calculated on the basis of the years 2014 to 2023.

In-migration proportions have been calculated for municipalities for each age and gender group
a) for migrants who stay in their own major migration region,
b) for migrants from other major migration regions, and
c) for migrants from abroad into the major migration region.

The proportions were calculated from the sum of the in-migrations in the major migration region to which the municipality belongs. In-migration proportions of the migrants from the municipality's own major migration region were calculated on the basis of the years 2014 to 2023. In-migration proportions of the migrants from other major migration regions and for the migrants from abroad were calculated on the basis of the years 2014 to 2023. All migration coefficients and in-migration proportions have been kept constant throughout the projection period. When calculating municipalities' proportions of migration from abroad, immigration by Ukrainians was eliminated.

In the calculation containing migration, the net immigration for the whole country is assumed to be 52,000 persons in 2024, 45,000 persons in 2025 and after that 40,000 persons per year. Immigration is obtained by calculating the emigration of the whole country and by summing up the assumed net immigration. The age distribution of immigration is calculated on the basis of immigration during 2014 to 2023. Immigration is divided into the major migration regions on the basis of the immigration proportion coefficient of each region. The immigration proportion of the major migration regions of the immigration of the whole country was calculated by age group and gender on the basis of the years 2014 to 2023. Municipalities’ immigration was calculated from the sum of immigration to their own major region by using the in-migration proportion coefficient.

The validation has already been carried out when compiling source data.

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

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)

The population projection is derived data. It does not contain data on individuals that would require data protection.

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

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 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.

Until 1972, population projections by municipality were published in the “Tilastollisia tiedonantoja” series, then until 1985 in the “Tilastotiedotus VÄ” series and after that in the OSF Population series. Municipalities' projected figures by age group were published as a separate volume of the 1969 projection, while age structure data by municipality from later projections were available as photocopies. In the 1990s, the data were mainly supplied as Excel tables. Previous projection files by municipality were not retained. Data on the population projections made in 2001, 2004, 2007, 2009, 2012, 2015, 2018, 2019, 2021 and 2024 are available in electronic format.

Data from the latest population projection are available free-of-charge in the PX-Web StatFin data service on the Internet at: https://pxdata.stat.fi/PXWeb/pxweb/en/StatFin/StatFin__vaenn/?tablelist=true.

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.

The quality of the population projection is assessed at several stages of the statistical process. The accuracy of previous population projections are also assessed subsequently. On the other hand, the function of a population projection is to provide decision-makers with an opportunity to assess to what the observed population development would lead if it continued and whether the direction of development should be changed. Therefore, a population projection should not be fulfilled if it has been possible to change the development through political decisions.

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 quality criteria of Official Statistics of Finland are compatible with the European Statistics Code of Practice.

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

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