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Concepts and definitions

Age

In connection with vital events, age data refer to the age on the day the event took place. Average age is obtained by adding up the ages of all persons involved in the same event at the time of the event, after which the sum is divided by the number of these persons. As the used age of a person is given in full years at the time of the event, it is not the exact age of that person. For this reason, it is assumed when computing average age that the persons were aged x+0.5, on average, at the time of the event.

Immigration

Persons who have moved to Finland and who intend to reside in Finland for more than twelve months or have resided in Finland over three months without interruption must notify the authorities of their move (Population Data Act 507/1993). Foreign nationals who intend to live permanently in Finland must have fulfilled during a year the preconditions of residence (EU national) and have a valid residence permit for longer time than one year (see Act 399/2007). In such cases their place of domicile is determined according to the same principles as for Finnish nationals (Municipality of Residence Act 201/1994).

Immigrants in usually resident population are not counted diplomats and those involved in development co-operation, etc. (Act on the Municipality of Domicile 201/1994). In accordance with an agreement between the Nordic countries, a period of temporary residence of less than six months is not construed as a move (On the Entry into Force of the Agreement Relating to the Population Registers in the Nordic countries 851/1990, Agreement Series 49 and Statute on the Municipality of Domicile 351/1994).

When a person migrates from one Nordic country to another, the local population register of the country of exit must provide the migrant with a Nordic Certification of Notice of Departure to be delivered to the local population register of the country of arrival (Decree on the Municipality of Domicile 351/1994, 851/1990, Agreement Series 49). The local population register authority of the country of arrival returns the certification to the register centre of the country of departure. The day on which the migrant is entered into the local population register of the country of arrival is recorded as the date of move.

Increase of population

Increase of population is the sum of excess of births over deaths and net immigration.

Intermunicipal in-migration

Persons having moved from one municipality to another reported to the Population Information System. One person may have several moves during the year in the statistics. Students' moves to the location of study can be regarded, if so desired by the student, as permanent moves from 1 June 1994, when the Act on the Municipality of Domicile (201/1994) came into force.

Intermunicipal net migration

Intermunicipal net migration is the difference between intermunicipal in-migration and intermunicipal out-migration.

Intermunicipal out-migration

Persons having moved from one municipality to another reported to the Population Information System. One person may have several moves during the year in the statistics. Students' moves to the location of study can be regarded, if so desired by the student, as permanent moves from 1 June 1994, when the Act on the Municipality of Domicile (201/1994) came into force.

Internal migration

Those changing place of domicile are expected within one week of the move to report on the change of address, specifying all family members involved in the move. The notice is delivered to the register office of the new place of residence. The move is indicated as either a permanent or a temporary one, and once the register office receives the notice, the register office determines whether the nature of the move involves a permanent or temporary change of domicile. Since 1 June 1994, when the Act on the Municipality of Domicile (201/1994) came into effect, students moving due to their studies have had the right to register themselves as permanent residents in the municipality in which they study. Data on the change of dwelling and place of domicile are transferred in machine-language format to the Population Information System. The register office of the new place of residence sends the data on the new place of domicile to the register office of the former place of residence. (Population Data Act 507/1993 and amendment 202/1994; Act on the Municipality of Domicile 201/1994; Decree on the Municipality of Domicile 351/1994)

Intramunicipal migration

Statistics Finland receives information on the changes in place of residence that involve a permanent change of domicile. These changes in domicile are classified at Statistics Finland into intramunicipal moves and intermunicipal moves. Intramunicipal moves consist of moves from one dwelling to another within the same municipality, with moves from one building or house to another forming a separate sub-category. Intramunicipal statistics dating to 1986 and earlier cover only moves from one building or house to another within the same municipality.

Until 1993, the concept of intramunicipal migration consisted of moves from one private dwelling unit to another within the same municipality. Since 1994, intramunicipal moves from institutional dwellings to private dwellings and vice versa have been included in the data. Moves from a situation where there is no permanent dwelling to private dwellings and vice versa have been classified as intramunicipal migration since 1994. This change in the concept has resulted in an increase of about 6 per cent in the intramunicipal migration data.

When the data for 1993 were produced, the statistical period was also changed from the period of 2 January to 1 January into 1 January to 31 December because of the corresponding change in the Population Information System. In the transition year the statistical period fell one day short of one year (the effect being 11,000 cases of intramunicipal migration and 4,500 cases of intermunicipal migration).

The coming into force of the Act on the Municipality of Domicile has somewhat increased the volume of intramunicipal and intermunicipal migration in 1994 and after that.

Mean population

The notion of mean population (or average population) refers to the average of the populations of two consecutive years. When a ratio describing some phenomenon is calculated for the statistical year, the number of events in the phenomenon in question is usually expressed as a proportion of the mean population of the people or the groups subject to the event. The figures relating to population events are generally given as per 1,000, that is, the result of the division is multiplied by one thousand.

Propensity for internal migration

The propensity for internal migration, or the rate of internal migration, refers to the number of migrants per 1,000 of the mean population in the area of departure. The propensity for internal migration in some age group indicates the migrants per 1,000 of the mean population in the age group in question.

Register correction (correction increase)

Register correction is to change a person's domicile information in the Population Information System so that the change of information does not involve an actual move of that person. In general, the move has taken place a very long time ago, in which case changing the information by a notice of removal would not make sense, or the person is known to have moved at some point but no information has been obtained on the target domicile and the person is thus included in the absent population.

When such an increase is made to the population living in an area, it is a question of an increase correction. When such a decrease is made to an area, it is a decrease correction. The difference between increase and decrease corrections is called register correction or net of register corrections.

Sex

The information about sex has been obtained from the Population Information System.

Total net migration

Total net migration is the sum of intermunicipal migration and net migration.