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Quality description, families 2018

1. Relevance of statistical information

The basic data file derives from the population information system of the Digital and Population Data Services Agency covers the population permanently resident in Finland on 31 December 2018.

The Digital and Population Data Services Agency maintains Finland’s Population Information System. The last population registration was carried out in Finland on 1 January 1989. After that the Population Information System has been updated by notifications of changes. The data stored in the Population Information System are specified in the act on the Population Information System and on the certificate services of the Digital and Population Data Services Agency (21 August 2009/661). Notifications on population changes for the past year are expected by the last day of January of the following year. At the beginning of February the Digital and Population Data Services Agency supplies to Statistics Finland the population data for the turn of the year.

Statistics Finland’s function is to compile statistics on conditions in society (Statistics Finland Act of 24 January 1992/48). These include also family statistics. Statistics Finland’s Rules of Procedure define the Population and Social Statistics unit as the producer of family statistics (Statistics Finland’s Rules of Procedure, TK-00-1808-19).


In the family statistics children comprise the following persons living with their parents:

  • biological children;

  • adopted children;

  • biological children and adopted children of one of the spouses.

Foster children and children in the care of the family are not classified as children.

The definition of child has changed since 1990. A child is now defined as a person who lives with his or her parents irrespective of his or her marital status, unless the person has a spouse or children who live in the same household-dwelling unit. In 1990 only unmarried persons were counted as children. So while in 1990 widowed or divorced persons living with their parents were classified as not belonging to families, since 1992 they have been regarded as members of the family.

A cohabiting couple is defined as two spouseless adults of different sex aged 18 and over and occupying the same dwelling on a permanent basis, provided their age difference is less than 16 years and they are not siblings. In case the couple has a common child these specifications do not apply. Same-sex persons living together are not inferred as cohabiting couples. Only registered partnerships are recorded in the statistics.

A dwelling refers to a room or a suite of rooms which is intended for year-round habitation; is furnished with a kitchen, kitchenette or cooking area; and has a floor area of at least 7 square metres. Every dwelling must have its own entrance. A single-family house may be entered through an enclosed porch or veranda. If a dwelling is entered through the premises of another dwelling, it is not regarded as a separate dwelling but the two constitute one dwelling.

The dwelling population comprises those persons who, according to the Population information system, resided permanently in dwellings at 31 December. Persons permanently institutionalised, living in residential homes and abroad and homeless people are not included in the dwelling population. Likewise, persons living in buildings classified as residential homes, whose living quarters do not meet the definition of dwelling, are not included.

The basic family population differs from the dwelling population in that it also includes those living in residential homes.

A family consists of a married or cohabiting couple or persons in a registered partnership and their children living together; or either of the parents and his or her children living together; or a married or cohabiting couple and persons in a registered partnership without children.

Starting from 1 March 2002, same-sex couples have been able to register their partnerships. By the amendment to the Marriage Act, same-sex persons have been able to enter into marriage starting from 1 March 2017. At the same time, registration of partnerships was abolished. Along with the amendment, persons in a registered partnership can change their partnership into a marriage by making a joint notification concerning it to the Digital and Population Data Services Agency.

Persons living in the household-dwelling unit who are not members of the nuclear family are not included in the family population, even if they are related, unless they form their own family. Brothers and sisters or cousins living together are not a family and do not belong to the family population. The same applies to people who live alone or with a person of the same sex, unless they form a married couple or a registered partnership.

Families living in residential homes are included in the family population. In contrast, persons who live in institutions are not included.

A family can consist of no more than two successive generations. If the household-dwelling unit comprises more than two generations, the family is formed starting from the youngest generation. This means, for example, that a mother-in-law or father-in-law living with their child’s family will not be included in the family population unless they live together with their spouse, in which case the old couple form their own family.

A family with underage children refers to a family which has at least one child aged under 18 living at home.

Family members are grouped by family status as follows:

  • spouse, no children;

  • spouse with children;

  • cohabiting partner, no children;

  • cohabiting partner with children;

  • partner in a registered partnership, no children;

  • partner in a registered partnership with children;

  • father/mother without spouse;

  • child.

In the family statistics children comprise all persons, regardless of age, who live with their parents, or the spouse’s biological or adopted children, but not foster children or children in the care of the family.

A family with underage children is a family comprising at least one child aged under 18 living at home.

A household-dwelling unit consists of the permanent occupants of a dwelling. Persons who, according to the Population Information System, are institutionalised, homeless, abroad, or registered as unknown, do not constitute household-dwelling units. Additionally, persons living in buildings classified as residential homes do not form household-dwelling units if their living quarters do not meet the definition of a dwelling.

When tabulating same-sex married couples or registered partnerships together with married or cohabiting couples, a man refers to the older partner of a same-sex married couple or a registered couple.

The number of children refers to the number of children who are living at home and have the status of a child.

The number of children in families with underage children refers to the number of children aged under 18 living at home.

In a reconstituted family , a child aged under 18 is a child of only one of the spouses. Not all the children aged under 18 in the family are common children.

A spouse refers to either a married or cohabiting partner or one of the partners of a registered partnership, unless otherwise indicated in the context.

Families are grouped into the following family types :

  • married opposite-sex couple without children;

  • married same-sex couple without children;

  • cohabiting opposite-sex couple without children;

  • married opposite-sex couple with children;

  • married same-sex couple with children;

  • cohabiting opposite-sex couple with children;

  • registered male couple without children;

  • registered male couple with children;

  • registered female couple without children;

  • registered female couple with children;

  • mother with children;

  • father with children.

A married or cohabiting couple without children refers to a couple who has never had any children or whose children no longer live with their parents. ‘Cohabiting couple with children’ contains couples who have common children and also couples whose children are not common.

For reasons of data protection, those living in registered partnerships are grouped together with married persons in municipal tables.

When tabulating same-sex married couples or registered partnerships together with married or cohabiting couples opposite sexes, wife refers to the younger partner of a same-sex married couple or a registered couple.

A man with a family is a married or cohabiting partner, a father with children and both partners of a registered male couple.

A woman with a family is a married or cohabiting partner, a mother with children and both partners of a registered female couple.

2. Methodological description of survey

The computer program classifies persons on the basis of their permanent place of residence code into household-dwelling units. The record of each person permanently residing in the dwelling includes the personal identification codes of his or her parents, spouse and children. By comparing them the program forms the families.

Before 1990, cohabiting couples were solely inferred with the help of common children. Since year 1992 inferences have been made using a revised program. After joining married couples in the household-dwelling units, this program identifies as cohabiting partners persons who live in the same dwelling, do not have a spouse, are aged 18 or over, and are of the opposite sex, provided that they are not siblings and their age difference is not more than 15 years. These rules do not apply to cohabiting couples with common children.

According to the former concepts, a spouseless mother with whom a man of suitable age is residing will be classified as a cohabiting couple. Likewise, the daughter of a family and a man of suitable age possibly residing with the family now form a cohabiting couple.

The inference of families is made difficult by the fact that the population information system is unable to distinguish between subtenants and the rest of the family. According to the reliability study of the 1990 census, there were less than 20,000 subtenants in Finland at that time and nothing indicated that the amount would be growing. Hence, any inferences where the subtenant is identified as the cohabiting partner of the landlord/lady cannot amount to any considerable number, as the precondition is that the subtenant is of a suitable age and a different sex from the spouseless landlord/lady.

If there is more than one suitable candidate, the program selects the person closest in age. If there are more than four persons without a spouse, the program does not classify them as cohabiting couples.

Families are not formed from institutionalised persons.

3. Correctness and accuracy of data

Family statisticians in Finland are privileged in that they have access to a population information system in which each person has, besides his or her personal identification code, also a domicile code, which tells the dwelling where he or she lives. Family statistics can be compiled from the entire population on an annual basis and quickly without burdening people with costly enquiries. Besides Finland, Denmark is the only other country where this is possible.

The inference of families from the population information system causes problems, mainly in two respects:

1. Only persons who are registered as domiciled in the same dwelling can be linked as a family.

2. Cohabiting couples (marriage-like relationship) will have to be inferred.

1. According to international concept definitions , the family can also be formed on the basis of the official place of residence, as is done in Finland. However, the families where one of the spouses is registered as domiciled in another locality, due to work, for example, will not be entered in the statistics as complete although he or she spends the weekends and vacations with the rest of the family. Likewise, a couple may reside together, although one of them is still registered as domiciled in some other place, with his or her previous spouse, for example.

In Finland the majority of people do, however, live in the place where they are registered as domiciled. In general, the Population Information System of the Digital and Population Data Services Agency can be considered very exhaustive as regards persons. In order that a person obtains a personal identity code, he or she has to be registered in the Population Information System. It is practically impossible to live in Finland without a personal identity code. A personal identity code is needed so that one can work legally, open a bank account, have dealings with authorities and so on. It can be safely assumed that Finland cannot have any substantial numbers of ’moonlighters’ who receive their pay in cash for periods of over one year, for example. Staying in Finland for at least one year is the prerequisite for registering into the population of Finland.

After the abolishment of yearly checking of domicile registers in 1989 the Population Information System has been maintained only by notifications of changes to population information. Their correctness is determined by a reliability survey made on the addresses in the Population Information System.

The Digital and Population Data Services Agency charges Statistics Finland with the task of conducting a sample survey on correctness of address information. Around 11,000 people are asked whether their address in the Population Information System is correct. In the 2012 survey, the address was correct for 98.9 per cent of the respondents. The non-response of this survey was 16.9 per cent. As regards the non-response, attempts were made to check the addresses from other sources. The address could be ascertained as correct for 92.3 per cent and as incorrect for 5.9 per cent of the persons included in the non-response. The address of 1.8 per cent of the persons in the non-response could not be checked. If we assume that all the unchecked data of persons in the non-response are incorrect, the final proportion of correct addresses would be 98.1 per cent.

In connection with municipal elections, returned notifications of voting sent to foreigners usually reveal around 1,000 persons who have moved from the country without giving notice and are thus still included in the Finnish population. The Digital and Population Data Services Agency removes them from the resident population in the Population Information System before the following turn of the year.

A total of 12,215 persons who have probably moved abroad have been removed after analyses from the population data derived from the Population Information System for the end of 2018. These persons are foreign citizens whose address is unknown and who have not received wages and salaries, capital income, entrepreneurial income, unemployment benefit, pension income, income support or compensation from sickness insurance between 2016 and 2017.

Unlike before, students may register as domiciled in the locality where they are studying thanks to the Municipality of Residence Act. The Act came into effect in 1994.

2. Inferring a marriage-like relationship from the population information system is more problematic. One alternative is not to enter childless cohabiting couples in the statistics at all and to link cohabiting couples only with the help of common children. But since statistics are supposed to give as truthful a picture of society as possible, we will surely get closer to the truth by inferring cohabiting couples on the basis of a common address than by leaving them out of the statistics altogether.

The program is also bound to infer non-existing cohabiting couples. On the other hand, it does not classify as cohabiting couples persons aged under 18, nor does it classify those whose age difference is over 15 years as such. The number of cohabiting couples inferred with the help of the program is, however, very close to the figures obtained by interview surveys conducted before the inference was started.

In 1989 cohabiting couples were obtained by a separate interview survey. The interview focused on persons, not families. The question was only posed to persons whose marital status was 'not married'. On the basis of the sample, it was estimated that there were 372,000 cohabiting persons aged 15-64 in Finland. In the family statistics for the following year 370,000 persons were classified on the basis of their addresses as cohabiting persons aged 18-64. However, some of these persons had the marital status 'married'. According to the samples, the number of cohabiting persons grew at an annual rate of some 20,000 at the end of the 1980s.

By taking into consideration the differences in age limits and the importance of the marital status in the inference of cohabiting couples, it may be observed that, by inference, the number of cohabiting couples is slightly smaller than the real situation measured by samples. The inference of cohabiting couples does, however, convey a good enough picture of the family structure in Finnish society. Hence it helps us to monitor the trend in families and to examine different types of families as larger groups. Certain caution should, however, be exercised in making unit-level inferences on the basis of these couples.

4. Timeliness and promptness of published data

Statistics Finland dates the population at the turn of the year as at the last day of the year. Since 1999 the regional division used has been that of the first day of the following year. Thus the municipalities that unite on the first day of the new year are already combined in the statistics on the last day of the previous year. Where necessary, statistics at the turn of year can also be produced with the municipality division before the unification.

5. Accessibility and transparency/clarity of data

The first family statistics are available from the 1950 and 1960 population censuses. From 1970 onwards population censuses have been conducted every five years. In addition, family data have been published in the years 1977, 1978, 1982, 1984 and 1987. Since 1992 family statistics have been compiled yearly. The Families publication has been produced yearly from 1994.

From 1980 to 1989, a yearly review based on a sample of around 10,000 persons was conducted on those living in consensual union in connection with the Labour Force Survey.

From 1870 to 1930 a population census based on person questionnaires was made in major towns every ten years. Some information about household-dwelling units is available from these censuses.

Basic family data are available in electronic form by municipality or with larger regional divisions than municipality in Statistics Finland’s free ‘Population’ online service on the Internet at:

General information and long time series on the families of the whole country can be obtained from the home page of Families at:

The chargeable information service contains more specified information about the families by sub-area of municipality, for example. More information about the service can be found at:

More information about Statistics Finland’s chargeable services is available at:

6. Comparability of statistics

Family data are not fully comparable before and after 1990, when cohabiting couples were first concluded on the basis of their living together. For the Families publication, family distributions, inclusive of cohabiting couples without common children, were estimated using the sample surveys for the whole country for the years 1960 and 1970. The figures for 1980 and 1985 were extracted from the original data with the new classification. Inclusion of cohabiting couples in the statistics increases the number of families and at the same time decreases the number of one-parent families, because some of these parents are cohabiting with their new spouses.

The fact that the marital status of the person classified with the status of a child has not been limited after 1990 also increases the number of families. For example a divorced person who comes back to live with his or her mother forms a family with the mother, while earlier the mother and the child were recorded as being outside the family population.

7. Coherence and consistency/uniformity

The figures of demographic family statistics differ somewhat from the family figures of population censuses. In these census statistics the concept is household-dwelling population, whereby the families whose dwellings do not fulfil the criteria for a dwelling are excluded from statistic on family.

Source: Population and Justice Statistics, Statistics Finland

Inquiries: Marjut Pietiläinen 029 551 2798, Joonas Toivola 029 551 3355, Timo Nikander 029 551 3250,

Director in charge: Jari Tarkoma

Updated 31.01.2020

Referencing instructions:

Official Statistics of Finland (OSF): Families [e-publication].
ISSN=1798-3231. annual review 2018, Quality description, families 2018 . Helsinki: Statistics Finland [referred: 25.9.2023].
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