Census 2021 round (cens_21)

1.1. Contact organisation

Instituto Nacional de Estatística, IP / Statistics Portugal

1.2. Contact organisation unit

Gabinete Censos / Cenus Unit

1.3. Contact name

Confidential because of GDPR

1.4. Contact person function

Confidential because of GDPR

1.5. Contact mail address

Av. António José de Almeida

1000-043 Lisboa

Portugal

1.6. Contact email address

Confidential because of GDPR

1.7. Contact phone number

Confidential because of GDPR

1.8. Contact fax number

Confidential because of GDPR

2.1. Metadata last certified

26 June 2024

2.2. Metadata last posted

26 June 2024

2.3. Metadata last update

26 June 2024

3.1. Data description

The data present the results of the 2021 EU census on population and housing, following Regulation (EC) 763/2008; Regulation (EU) 2017/543; Regulation (EU) 2017/712 and Regulation (EU) 2017/881.

3.1.1. Impact of the COVID-19 pandemic on census methodology

In the epidemiological context (COVID-19) and after a rigorous analysis and assessment of the feasibility  of its implementation by Statistical Portugal (SP), a Contingency Plan was defined in order to guarantee the quality of Census execution and safeguard risks to the population and for the data collection structure.

This Contingency Plan was based on the following lines of action:

• A strategy that reinforced the option of responding to Censuses via the internet, with support to the population through a specific Help line, allowing an easy, safe and quick response approach for citizens. In context epidemiologically, this mode of response was even more relevant, also taking into account that reduce contacts between enumerators and the population;
• The possibility of telephone response, aimed essentially at groups within the population with greater difficulty in responding via the internet or prevented from face-to-face contact, particularly for public health reasons;
• Reinforcement of fieldwork control and validation mechanisms namely using administrative data;
• Compliance with a Public Health Protocol for the preparation and execution of the 2021 Census, within the scope of the COVID-19 pandemic, which made it possible to ensure the application of health standards established by health authorities.

This protocol followed the technical guidelines of the Directorate-General for Health (DGS) and integrated specific recommendations from this entity for the preparation and carrying out the census operation

3.2. Classification system

The following classification were used:

1. Nomenclature of Territorial Units for Statistics (NUTS 2021)
2. International Standard Classification of Education (ISCED-2011)
3. International standard classification of occupations (ISCO-08)
4. Statistical Classification of Economic Activities in the European Community (NACE Rev 2)

3.3. Coverage - sector

Not applicable.

3.4. Statistical concepts and definitions

The information is given separately for each census topic.

3.4.1. Statistical concepts and definitions - Usual residence

‘Usual residence’ is the place where a person normally spends the daily period of rest, regardless of temporary absences for purposes of recreation, holidays, visits to friends and relatives, business, medical treatment or religious pilgrimage.

The following persons alone shall be considered to be usual residents of the geographical area in question:

(i) those who have lived in their place of usual residence for a continuous period of at least 12 months before the reference date

(ii) those who arrived in their place of usual residence during the 12 months before the reference date with the intention of staying there for at least one year

Where the circumstances described in point (i) or (ii) cannot be established, ‘usual residence’ shall mean the place of legal or registered residence.

3.4.2. Statistical concepts and definitions - Sex

‘Sex’ refers to the biological and physiological characteristics that define men and women.

3.4.3. Statistical concepts and definitions - Age

The age reached in completed years at the reference date.

3.4.4. Statistical concepts and definitions - Marital status

Marital status is defined as the (legal) conjugal status of an individual in relation to the marriage laws (or customs) of the country (that is the de jure status).

A person shall be classified according to his/her most recently acquired legal marital status at the reference date.

Portuguese legislation establishes/allows:

• 16 years old as the minimum age for marriage. However, until the majority age (18 years) is required permission from parents or legal guardian;
• Same-sex marriages, since June 2010;
• Divorce, since 1910.

The concept of "registered partnership" does not exist in Portuguese legislation.

3.4.5. Statistical concepts and definitions - Family status

The family nucleus is defined in a narrow sense; that is as two or more persons who belong to the same household and who are related as husband and wife, as partners in a registered partnership, as partners in a consensual union, or as parent and child. Thus, a family comprises a couple without children or a couple with one or more children, or a lone parent with one or more children. This family concept limits relationships between children and adults to direct (first-degree) relationships, that is, between parents and children.

3.4.6. Statistical concepts and definitions - Household status

Statistics Portugal applies the household-dwelling concept to identify private households

Household-dwelling concept - considers all persons living in a housing unit to be members of the same household, such that there is one household per occupied housing unit.

3.4.7. Statistical concepts and definitions - Current activity status

For Statistics Portugal, the 'currently economically active population' comprises all persons who fulfil the requirements for inclusion among the employed or the unemployed.

•  'Employed' persons comprise all persons aged 15 years or over who during the reference week (12 to 18 april):

1. 1.  performed at least one hour of work for pay or profit, in cash or in kind, or
   2.  were temporarily absent from a job in which they had already worked and to which they maintained a formal attachment, or from a self-employment activity.

•  The 'unemployed' comprise all persons aged 15 years or over who were:

1. 1.  'without work', that is, were not in wage employment or self-employment during the reference week; and
   2.  'currently available for work', that is, were available for wage employment or self-employment during the reference week and for two weeks after that; and
   3.  'seeking work', that is, had taken specific steps to seek wage employment or self-employment within four weeks ending with the reference week.

The category 'Currently not economically active' includes persons below the national minimum age for economic activity (15 years).

In ascribing a single activity status to each person, priority is given to the status of 'employed' in preference to 'unemployed', and to the status of 'unemployed' in preference to 'not economically active'.

3.4.8. Statistical concepts and definitions - Occupation

Occupation refers to the type of work done in a job. ‘Type of work’ is described by the main tasks and duties of the work.

Persons are classified according to the occupation they had during their most recent employment. The categories included in the breakdown 'occupation' correspond to the major groups of the ISCO-08 (COM) classification.

Persons under the age of 15 years, as well as persons aged 15 or over that were:

• not economically active during the reference week (12 to 18 april), or
• unemployed, never worked before (i.e. they have never been employed in their lives)

are classified under 'not applicable'.

The allocation of a person within the breakdowns of the topics 'Occupation', 'Industry' and 'Status in employment' is based on the same job.

3.4.9. Statistical concepts and definitions - Industry

Industry (branch of economic activity) refers to the kind of production or activity of the establishment or similar unit in which the job of an employed person is located.

Persons doing more than one job shall be allocated an industry (branch of economic activity) based on their main job, which is to be identified according to the time spent on the job or the income received.
The breakdown by industry is available for persons aged 15 or over that were employed during the reference week (12 to 18 april).
The categories included in the breakdown 'industry' list the 21 sections of the NACE Rev. 2 classification and appropriate aggregates.

3.4.10. Statistical concepts and definitions - Status in employment

An ‘employee’ is a person who works in a ‘paid employment’ job, that is a job where the explicit or implicit contract of employment gives the incumbent a basic remuneration, which is independent of the revenue of the unit for which he/ she works. An ‘employer’ is a person who, working on his or her own account or with a small number of partners, holds a ‘self- employment’ job and, in this capacity, on a continuous basis (including the reference week) has engaged one or more persons to work for him/her as ‘employees’.

3.4.11. Statistical concepts and definitions - Place of work

The location of the place of work is the geographical area in which a currently employed person does his/her job.

The place of work of those mostly working at home is the same as their usual residence. The term ‘working’ refers to work done as an ‘employed person’ as defined under the topic ‘Current activity status’. ‘Mostly’ working at home means that the person spends all or most of the time working at home, and less, or no, time in a place of work other than at home.

Information on persons who do not have a fixed place of work but who report to a fixed address at the beginning of their work period (for example bus drivers, airline crew, operators of street market stalls that are not removed at the end of the workday) refer to that address. This group may also include individuals who travel to work, on a regular basis, across the border to a neighbouring country. Breakdown ‘No fixed place of work (inside or outside the Member State)’ includes all persons without fixed place of work but will also refer to persons such as sailors, fishermen and offshore workers for whom it may not be possible to allocate the place of work.

Even due to the covid-19 the place of work should refer to the place where usually work. 
Instructions were given to respond according to their usual place of work, even if they were working from home due to covid-19.

3.4.12. Statistical concepts and definitions - Educational attainment

Educational attainment refers to the highest level successfully completed in the educational system of the country where the education was received. All education which is relevant to the completion of a level is taken into account even if this was provided outside schools and universities.

3.4.13. Statistical concepts and definitions - Size of the locality

A locality is defined as a distinct population cluster that is an area defined by population living in neighboring or contiguous buildings with at least 10 dwellings, and to which a distinct place name is attached.

3.4.14. Statistical concepts and definitions - Place of birth

Information on the ‘Place of birth’ is collected according to the place of usual residence of the mother at the time of the birth, or, if not available, the place in which the birth took place, on the basis of international boundaries existing on 1 January 2021.

For reporting countries that are EU Member States, the sub-category under the category 'other EU Member State' that refers to their Member State does not apply. For reporting countries that are not EU Member States, the category 'Other EU Member State' shall be read as 'EU Member State'.
The category 'Information not classifiable according to current borders' covers those persons whose country of birth existed at the time of the birth, but no longer exists at the time of the census, and who cannot be allocated uniquely to one country existing at the time of the census, i.e. according to current borders.
The category 'outside any country' covers persons for whom the usual residence of the mother at the time of the birth is not known and who where born outside the borders of any country, for example at sea or in the air.

3.4.15. Statistical concepts and definitions - Country of citizenship

Citizenship is defined as the particular legal bond between an individual and his/her State, acquired by birth or naturalization, whether by declaration, option, marriage or other means according to the national legislation. A person with two or more citizenships is allocated to only one country of citizenship, to be determined in the following order of precedence:

1. reporting country
2. if the person does not have the citizenship of the reporting country: other EU Member State
3. if the person does not have the citizenship of another EU Member State: other country outside the European Union.

'EU Member State' means a country that is a member of the European Union on 1 January 2021. The list of countries in the breakdown 'Country of citizenship' shall only apply for statistical purposes.
For reporting countries that are EU Member States, the sub-category of the category 'citizenship not of reporting country, but other EU Member State' that refers to their Member State does not apply. For reporting countries that are not EU Member States, the category 'citizenship not of reporting country, but other EU Member State' shall be changed to 'citizenship of an EU Member State'.
Persons who are neither citizens of any country nor stateless and who have some but not all of the rights and duties associated with citizenship shall be classified under 'recognised non-citizens'.

3.4.16. Statistical concepts and definitions - Year of arrival in the country

The year of arrival is the calendar year in which a person most recently established usual residence in the country.

The data for 2021 refer to the time span between 1 January 2021 and the reference date.

3.4.17. Statistical concepts and definitions - Residence one year before

The relationship between the current place of usual residence and the place of usual residence one year prior to the census.

For Portugal the reference date for residence one year prior to census is 31 December 2019

As the census took place on 19 April 2021, there are a number of children who have more than one year old (at the time of the census) but who had not been born on 31 December 2019.

We classified as “Not applicable” all children who had not been born on 31 December 2019.

For all persons that have changed their usual residence more than once within the year prior to the reference date, the previous place of usual residence is the last usual residence from which they moved to their current place of usual residence.

3.4.18. Statistical concepts and definitions - Housing arrangements

The topic ‘Housing arrangements’ covers the whole population and refers to the type of housing in which a person usually resides at the time of the census. This covers all persons who are usual residents in different types of living quarters, or who do not have a usual residence and stay temporarily in some type of living quarters, or who are roofless, sleeping rough or in emergency shelters, when the census is taken.

'Other housing units' are huts, cabins, shacks, shanties, caravans, houseboats, barns, mills, caves or any other shelter used for human habitation at the time of the census, irrespective if it was designed for human habitation.
'Collective living quarters' are premises which are designed for habitation by large groups of individuals or several households and which are used as the usual residence of at least one person at the time of the census.
'Occupied conventional dwellings', 'other housing units' and 'collective living quarters' together represent ‘living quarters'. Any 'living quarter' must be the usual residence of at least one person.

The sum of occupied conventional dwellings and other housing units represents 'housing units'.
The homeless (persons who are not usual residents in any living quarter category) can be persons living in the streets without a shelter that would fall within the scope of living quarters (primary homelessness) or persons moving frequently between temporary accommodation (secondary homelessness).

3.4.19. Statistical concepts and definitions - Type of family nucleus

The family nucleus is defined in a narrow sense; that is as two or more persons who belong to the same household and who are related as husband and wife, as partners in a registered partnership, as partners in a consensual union, or as parent and child. Thus a family comprises a couple without children or a couple with one or more children, or a lone parent with one or more children. This family concept limits relationships between children and adults to direct (first-degree) relationships, that is, between parents and children.

Child (son/daughter) refers to a blood, step- or adopted son or daughter (regardless of age or marital status) who has usual residence in the household of at least one of the parents, and who has no partner or own children in the same household. Foster children are not included. A son or daughter who lives with a spouse, with a registered partner, with a partner in a consensual union, or with one or more own children, is not considered to be a child. A child who alternates between two households (for instance if his or her parents are divorced) shall consider the one where he or she spends the majority of the time as his or her household. Where an equal amount of time is spent with both parents the household shall be the one where the child is found at the time on census night.
The term couple shall include married couples, couples in registered partnerships, and couples who live in a consensual union.
Registered partnerships are reported only by countries that have a legal framework regulating partnerships that:

1. lead to legal conjugal obligations between two persons;
2. are not marriages;
3. prevent persons to commit themselves into multiple partnerships with different partners.

Two persons are considered to be partners in a 'consensual union' when they

• belong to the same household, and
• have a marriage-like relationship with each other, and
• are not married to or in a registered partnership with each other.

'Skip-generation households' (households consisting of a grandparent or grandparents and one or more grandchildren, but no parent of those grandchildren) are not included in the definition of a family.

3.4.20. Statistical concepts and definitions - Size of family nucleus

The family nucleus is defined in a narrow sense; that is as two or more persons who belong to the same household and who are related as husband and wife, as partners in a registered partnership, as partners in a consensual union, or as parent and child. Thus a family comprises a couple without children or a couple with one or more children, or a lone parent with one or more children. This family concept limits relationships between children and adults to direct (first-degree) relationships, that is, between parents and children.

3.4.21. Statistical concepts and definitions - Type of private household

Statistics Portugal applies the household-dwelling concept to identify private households

Household-dwelling concept - considers all persons living in a housing unit to be members of the same household, such that there is one household per occupied housing unit.

'Primary homeless persons' are persons living in the streets without a shelter that would fall within the scope of living quarters.

3.4.22. Statistical concepts and definitions - Size of private household

Statistics Portugal applies the household-dwelling concept to identify private households

Household-dwelling concept - considers all persons living in a housing unit to be members of the same household, such that there is one household per occupied housing unit.

'Primary homeless persons' are persons living in the streets without a shelter that would fall within the scope of living quarters.

3.4.23. Statistical concepts and definitions - Tenure status of households

The topic ‘Tenure status of households’ refers to the arrangements under which a private household occupies all or part of a housing unit.

3.4.24. Statistical concepts and definitions - Type of living quarter

A living quarter is housing which is the usual residence of one or more persons.

'Conventional dwellings' are structurally separate and independent premises at fixed locations which are designed for permanent human habitation and are, at the reference date, either used as a residence, or vacant, or reserved for seasonal or secondary use.
'Separate' means surrounded by walls and covered by a roof or ceiling so that one or more persons can isolate themselves. 'Independent' means having direct access from a street or a staircase, passage, gallery or grounds.
'Other housing units' are huts, cabins, shacks, shanties, caravans, houseboats, barns, mills, caves or any other shelter used for human habitation at the time of the census, irrespective if it was designed for human habitation.
'Collective living quarters' are premises which are designed for habitation by large groups of individuals or several households and which are used as the usual residence of at least one person at the time of the census.
'Occupied conventional dwellings', 'other housing units' and 'collective living quarters' together represent ‘living quarters'. Any 'living quarter' must be the usual residence of at least one person.

3.4.25. Statistical concepts and definitions - Occupancy status

‘Occupied conventional dwellings’ are conventional dwellings which are the usual residence of one or more persons at the time of the census. ‘Unoccupied conventional dwellings’ are conventional dwellings which are not the usual residence of any person at the time of the census.

3.4.26. Statistical concepts and definitions - Type of ownership

‘Type of ownership’ refers to the ownership of the dwelling and not to that of the land on which the dwelling stands. It shows the tenure arrangements under which the dwelling is occupied.

'Owner-occupied dwellings' are those where at least one occupant of the dwelling owns parts or the whole of the dwelling 'Rented dwellings' are those where at least one occupant pays a rent for the occupation of the dwelling, and where no occupant owns parts or the whole of the dwelling.

3.4.27. Statistical concepts and definitions - Number of occupants

The number of occupants of a housing unit is the number of people for whom the housing unit is the usual residence.

3.4.28. Statistical concepts and definitions - Useful floor space

Useful floor space is defined as the floor space measured inside the outer walls excluding non-habitable cellars and attics and, in multi-dwelling buildings, all common spaces; or the total floor space of rooms falling under the concept of 'room'.

3.4.29. Statistical concepts and definitions - Number of rooms

A ‘room’ is defined as a space in a housing unit enclosed by walls reaching from the floor to the ceiling or roof, of a size large enough to hold a bed for an adult (4 square meters at least) and at least 2 meters high over the major area of the ceiling.

3.4.30. Statistical concepts and definitions - Density standard (floor space)

The topic ‘Density standard (floor space)’ relates the useful floor space in square meters to the number of occupants, as specified under the topic ‘Number of occupants’.

3.4.31. Statistical concepts and definitions - Density standard (number of rooms)

The topic ‘Density standard (number of rooms)’ relates the number of rooms to the number of occupants, as specified under the topic ‘Number of occupants’.

3.4.32. Statistical concepts and definitions - Water supply system

According to the Census 2011, 99.4% of conventional dwellings were equipped with piped water. For 2021 Portugal did not collect this topic and assumes that all conventional dwelling are equipped  with piped water

3.4.33. Statistical concepts and definitions - Toilet facilities

According to the Census 2011, 99,2% of conventional dwellings were equipped with toilet facilities. For 2021 Portugal did not collect this topic and assumes that all conventional dwelling are equipped with toilet facilities

3.4.34. Statistical concepts and definitions - Bathing facilities

According to theCensus 2011, 98% of conventional dwellings were equipped with bathing facilities. In 2021 Portugal did not collect this topic and assumes that all conventional dwelling are equipped with bathing facilities

3.4.35. Statistical concepts and definitions - Type of heating

Conventional dwelling is considered as centrally heated if heating is provided either from a community heating centre or from an installation built in the building or in the conventional dwelling, established for heating purposes, without regard to the source of energy.

3.4.36. Statistical concepts and definitions - Type of building

The topic ‘Dwellings by type of building’ refers to the number of dwellings in the building in which the dwelling is placed.

3.4.37. Statistical concepts and definitions - Period of construction

The topic ‘Dwellings by period of construction’ refers to the year when the building in which the dwelling is placed was completed.

3.5. Statistical unit

The EU programme for the 2021 population and housing censuses includes data on persons, private households, family nuclei, conventional dwellings and living quarters.

3.6. Statistical population

The persons enumerated in the 2021 census are those who were usually resident in the territory of the reporting country at the census reference date.

Usual residence means the place where a person normally spends the daily period of rest, regardless of temporary absences for purposes of recreation, holidays, visits to friends and relatives, business, medical treatment or religious pilgrimage

3.7. Reference area

Data are available at different levels of geographical detail in EU countries: national, NUTS2/NUTS3, regions and local administrative units (LAU) and grids.

3.8. Coverage - Time

Data refer to the situation in the reporting country at the census reference date - 19 april 2021

3.9. Base period

Not applicable.

Counts of statistical units should be expressed in numbers and where is needed rate per inhabitants enumerated in the country.

See the following sub-concepts.

5.1. EU census reference date

19 April 2021

5.2. National census reference date

19 April 2021

5.3. Differences between reference dates of national and EU census publications

No differences.

6.1. Institutional Mandate - legal acts and other agreements

For the 2021 Census, specific legislation was prepared, embodied in Decree-Law 54/2019 of April 18, which defined the powers and responsibilities of the various entities involved in the census operation, establishing specific provisions to ensure the financial and human resources necessary for its execution.

6.1.1. Bodies responsible

SP is responsible for Census 2021 operation in all domains from conception, collection and dissemination procedures, namely:

• Preparing the 2021 Census action programme, organizing and supervise its implementation;
• Define the technical and administrative standards for the national, regional and local intervention of all entitiesinvolved in these statistical operation;
• Prepare the National Communication Program, to ensure the dissemination and awareness of the 2021 Census;
• Promote the recruitment, selection and hiring of coordinators and enumerators according to regional and local needs and ensure their training;
• Providing technical support and monitoring of data collection;
• Process treatment, validation and data compile;
• Ensuring data dissemination in different supports to respond to the needs and profiles of different users.
• Ensuring the definition, preparation and implementation of the quality control and evaluation program.

Section for Monitoring the 2021 Census (SEAC 2021) is the body of the National Statistical Council that monitored the work of the 2021 Census. This section is responsible for Monitor the preparation, execution, compilation and evaluation of the 2021 Census;

The Azores Regional Statistical Service and the Madeira Regional Statistical Directorate are responsible for coordinating and implementing the census operation in their respective Autonomous Regions;

Municipalities and Parishes are responsible for organising, coordinating and monitoring census tasks within their area of jurisdiction;

Governmental services and bodies - collect data from individuals for specials cases or some conditions, for instance, individuals in jail, working to the embassies, or other special cases.

6.2. Institutional Mandate - data sharing

Not applicable.

7.1. Confidentiality - policy

Article 6 of Law No 22/2008 of 13 May 2008, laying down the principles, rules and structure of the national statistical system, refers to the principle of statistical confidentiality and states that all individual data concerning individuals or groups gathered by the statistical authorities are confidential in nature and may not be disseminated in such a way as to permit direct or indirect identification.

Article 19, "Confidentiality", of Decree-Law No 54/2019 of 18 April 2019 (which lays down the rules to be obeyed by the 2021 Census) states that individual statistical data collected in the framework of the 2021 Census are subject to the principle of statistical confidentiality, constituting a professional secret for all persons who are involved in these statistical operations and have awareness of those data pursuant to Article 6 of Law No 22/2008 of 13 May 2008.

7.2. Confidentiality - data treatment

In 2021 Census, with the purpose of protected the privacy of individuals and to ensure that your identity and characteristics are not obtained from the data disclosed, a statistical method was applied to control the disclosure of data, called “Targeted Record Swapping”. The application of this method guarantees that the total resident population and its main characteristics, remain unchanged for the different geographic levels.

8.1. Release calendar

There is a release calendar for the census outputs and publicly accessible.

Main dates:

• 28 July 2021 – 2021 Census Preliminary results
• 16 dDecember 2021 – 2021 Census Provisional results
• 23 November 2022 – 2021 Census Final results

8.2. Release calendar access

Release calendar from Statistics Portugal data dissemination, available on SP portal (include census outputs) - link in annexe

 

Annexes:
Data Availability

8.3. Release policy - user access

The Dissemination policy of Statistics Portugal is user-oriented and assigns great importance to meeting user needs and expectations. The Dissemination policy of SP lays down the fundamental principles governing the dissemination of official statistics, directly or indirectly produced under its responsibility. It should have as main reference the applicable principles of the National Statistical System: technical independence, statistical confidentiality, quality and accessibility.

Statistics Portugal makes official statistics available under the terms of the national and international, legal and ethical framework governing the production of statistics.

Statistical data are made available impartially and simultaneously to all users.

Official statistical data are made available according to a pre-announced schedule, which is previously announce on the official statistics portal.

Decennial

See the following sub-concepts.

10.1. Dissemination format - News release

4 press releases were issued containing exclusive information about the 2021 Census:

• Census 2021 - Preliminary Results Released – 28 July 2021
• Census 2021 - Provisional Results Released – 16 December 2021
• Provisional Results of the 2021 Census - Geographic Base for Referencing Information (BGRI) – Geopackage – 13 April 2022
• Census 2021 - Definitive Results Released - Main trends in Portugal over the last decade – 23 November 2022

A Study Series Press Release: "What the Census tells us":

• Number 1 - "What the Census tells us about the difficulties faced by people with disabilities" (only available in portuguese); 
• Number 2  - "What the Census tells us about the population of foreign citizenship living in Portugal" (only available in portuguese);
• Number 3 - "What the Census tells us about family structures" (only available in portuguese);
• Number 4 - "What the Census tells us about housing" (only available in portuguese);
• Number 5 - "What the Census tells us about territorial dynamics" (only available in portuguese). 

Annexes:
Preliminary Results Released
Provisional Results
GEOPACKAGE
Definitive Results
Study Series - Number 1
Study Series - Number 2
Study Series - Number 3
Study Series - Number 4
Study Series - Number 5

10.2. Dissemination format - Publications

One publication were issued containing the final results of the 2021 Census

A Study Series Publications: "What the Census tells us":

• Number 1 - "What the Census tells us about the difficulties faced by people with disabilities"; 
• Number 2  - "What the Census tells us about the population of foreign citizenship living in Portugal";
• Number 3 - "What the Census tells us about family structures";
• Number 4 - "What the Census tells us about housing";
• Number 5 - "What the Census tells us about territorial dynamics".

Annexes:
Census - Definitive Results
Study Series - Publication Number 1
Study Series - Publication Number 2
Study Series - Publication Number 3
Study Series - Publication Number 4
Study Series - Publication Number 5

10.3. Dissemination format - online database

Information on the 2021 Census is available on the Statistics Portugal website: Censos 2021 (ine.pt)

Namely:

• Geocensus - Geographic application that allows the visualization, on a map, of a set of data on the Geographic Base for Referencing Information - BGRI 2021 (Statistical Section and Subsection) on the Census Place Base or the GRID 1km²
• Main Statistical Indicators - A set of around 300 statistical indicators available on the official statistics portal. Whenever possible, these indicators ensure the continuity of the census series and are made available down to parish level;
• Dissemination platform - This is an application that allows you to visualize and explore the main indicators of the 2021 Census, in graphs and maps, on the themes of Population, Households and Households and Housing, by geographical levels NUTS II, Municipality and Parish; 
• Stastical tables - Set of tabulation tables totaling 105 tables, available at parish level and ensuring historical series;
• Infographics - Illustrative summary of some census themes: Population, Households and Family Units and Housing;
• Geoescolas - Geographical application that allows you to obtain a set of data from the 2021 and 2011 Censuses relating to the area surrounding a particular school.

Annexes:
Geocensus
Indicators
Dissemination platform
Statistical tables
Infographics - Population
Infographics - Household and Family Units
Infographics - Housing
Geoescolas

10.4. Dissemination format - microdata access

Public Use File - Microdata sample - Two sets of Census 2021 microdata are available: It includes two sampling tables, one sampling table for family and collective dwellings, containing some variables on the building; and another sampling table for resident individuals, both with 5% anonymised registers and a common bonding variable.

These files (data and metadata) contain anonymised records, processed and prepared in a way that the observation unit cannot be identified directly or indirectly. Acces to this flies is free and respect the principle of statistical confidentiality and personal data protection. The access implies prior acceptance of use conditions.

Annexes:
Microdate Sample

10.5. Dissemination format - other

Geopackage - Application which allows you to extract geographical information on census territorial units and some associated census data. You can access BGRI data (statistical section and subsection) and GRID 1km². It is possible to access information on the Synthesis File at section and statistical subsection level.

In accordance with the implementing regulations for the Census 2021, the respective Data Programme was made available to the European Statistical System, composed of a set of hypercubes, metadata, quality reports and data by GRID 1Km2

In addition to the range of products on offer, there is also the possibility to customise products and services which, due to the specificity or complexity of the cannot be accommodated in standard product formats. The availability of customise products is dependent on analysing and safeguarding issues relating to personal data protection and confidentiality. Some of these customised products can be asked for different specific geographical regions

SP also respond to a wide range of international questionnaires, including the United Nations Demographic Yearbook Questionnaires on Population and Housing Censuses - 2020 round.

Annexes:
GEOPACKAGE

10.6. Documentation on methodology

Action programme for the 2021 Census - document providing a framework for the census operation and setting out the objectives, guidelines, variables to observe and a summary of the main activities to be combined for the performance of the census.

Annexes:
Action Programme

10.7. Quality management - documentation

The analysis of the results of the quality survey is a constant part of the publication Census 2021 - Definitive Results.

Annexes:
Definitive Results

11.1. Quality assurance

The performance of operations for the 2021 Census was accompanied by a far-reaching quality control and assessment programme. This programme concentrated on the following two areas:

• Quality control in the productive process;
• Performance of a Post Enumeration Survey

Quality control in the productive process including:

• Selection, training and evaluation of knowledge acquired at regional and local stakeholders. The programme of information sessions, made up of various modules, was designed taking into account the responsibilities and roles of the various players in the structure of the 2021 Census. The model for operationalising the sessions was "cascade". Cascade" model, with certain levels of the structure responsible for transmission to the next level of the collection structure.
• Fieldwork control: implementation of mechanisms to verify and monitor key points throughout the productive process that had the potential to compromise the quality of the results of the censuses, namely in the aspects human resources, field work, data processing and security. Example: Implementation of an alert indicator system: this system consists of monitoring certain census results (during collection) by comparison with the expected results, with reference to different sources of information (including administrative files). Whenever deviations are identified, according to parameters are identified, an additional fieldwork verification procedure

The quality of the results was assessed by means of a Post Enumeration Survey, conducted independently at the end of the data-gathering operation with the aim of quantifying the errors in the coverage and content of the census-taking operation.  Please see section 11.2.2 for more information

11.2. Quality management - assessment

The methodology associated with the control and assessment of the productive process concentrated on identifying and monitoring key processes to guarantee effective performance of the work in the field and the quality of the information collected.

In terms of fieldwork control, two procedures were applied to assess the quality of data collection:

• Re-survey of a sample of dwellings (5%), carried out by Parish Coordinators/Sub-coordinators
• System of alert indicators, which allowed monitoring of collection values by comparison with the expected results, with reference to different sources of information such as those of an administrative nature. Whenever you identified deviations, in view of established parameters, were triggered additional fieldwork verification procedures

In aditional it was carried out, the 2021 Post Enumeration Survey , an autonomous and independent statistical operation during which some of the statistical units observed in the 2021 Census were re-surveyed. The main aims of the Post Enumeration Survey were to assess errors in coverage and in content for a set of variables. A sample of 139 statistical sections was defined to ensure the regional representativeness (NUTS II) for a set of variables. Data were collected exclusively via face-to-face interviews carried out by teams other than those used for the 2021 Census. 

The methodology and results of the  Post Enumeration Survey are contained in the publication Census 2021 - Definitive Results 

 

11.2.1. Coverage assessment

The 2021 Post Enumeration Survey, was an autonomous and independent statistical operation during which some of the statistical units observed in the 2021 Census were re-surveyed.The main aims of the Post Enumeration Survey, were to assess errors in coverage and in content for a set of variables.A sample of 139 statistical sections was defined to ensure the regional representativeness (NUTS II) for a set of variables.Data were collected exclusively via face-to-face interviews carried out by teams other than those used for the 2021 Census.

In terms of coverage, the results are:

• Census Population (absolute value) - 10 343 066
• Estimated target population (absolute value) - 10 683 344
• Estimated target population (Percentage) - 96,8%
• Under-coverage (estimated - absolute value) - 340 278
• Under-coverage (estimated - percentage) - 3,2% 

11.2.2. Post-enumeration survey(s)

The Post-enumeration survey (PES) is part of the census control and evaluation program quality of the 2021 Census.

Its objective is to obtain relative indicators the completeness of the count of statistical units observed in the Censuses, as well evaluated the consistency of some characteristics of resident individuals.
Given the importance and complexity of this statistical operation, SP decided that the technical and methodological options adopted were evaluated by a external entity. A team from ISCTE - Instituto Universitário de Lisboa was selected for this assessment.
PES is a statistical sampling operation carried out independently after the completion of the Census.
Data collection took place between September and November 2021. This calendar was defined taking into account the pandemic situation and possible repercussions on the Census collection calendar.
The data collected in PES refers to the Census moment (19 April 2021) as in the Census operation.
A sample of 139 statistical sections was defined to ensure the regional representativeness (NUTS II) for a set of variables. Data were collected exclusively via face-to-face interviews carried out by teams other than those used for the 2021 Census.
The coverage analysis intends to obtain indicators on the quality of the results of the Censuses, for each Statistical Unit considered, to verify whether they were duly listed, wrongly listed or omitted.
At the national level, for conventional dwellings where estimated a coverage rate of 102.7% and for individuals the estimated coverage rate was 96.8%.
The content analysis focuses on the statistical unit Individual living in private households and main demographic characteristics: sex and age group. The PES revealed that for the sex variable, the consistency rate was 99.8%, and of 99.5% for age group.

12.1. Relevance - User Needs

The census data disseminated by Eurostat are addressed to policy makers (Central and Local authorities), researchers, media and the general public

In preparation for the 2021 Census, Statistics Portugal consulted census data users to assess their needs and identify data gaps.

Census data makes it possible to obtain a "snapshot" of people and their living conditions at each geographical level. This way we know: how many we are, what we look like, where we live, how we live. In this way information from censuses serve for a great variety of uses, for example:

• for setting policies in various fields: education, health, welfare, housing, transportation and other services;
• population censuses are an important resource for research on trends in the composition of a population and its distribution, as well as a source of analysis and assessment of the country's social and economic structure, its evolution and trends, as well as comparisons with other societies and countries;
• the Census is a unique and renewable source of data that is a valuable tool for diagnosis, planning and intervention in a wide range of areas: Regional and local planning, market research, research in social sciences,...

No shortcomings in census outputs were reported by users

12.2. Relevance - User Satisfaction

Measuring user satisfaction of Statistics Portugal products and services is a commitment stated in Statistics Portugal Quality Charter, and duly aligned with the European Statistics Code of Practice.

Statistics Portugal has a user support service through which it receives requests for custom design analyses and provides guidance for statistics consultation on Statistics Portugal Portal. After the requested service has been provided, users who have specified an e-mail address automatically receive an online satisfaction survey to assess the service (the post-service user satisfaction survey). Users have the possibility to provide feedback in an open question (comments and suggestions). The results from users’ satisfaction consultations are available through a “User Satisfaction Index”.

 The last results are:

 Year - Value*

 2018 - 0,77

 2019 - 0,81

 2020 - 0,83

 2021 - 0,84

 2022 - 0,85

  *Results according “extreme response balance” (ERB)

 In addition, following the submission of the response to the 2021 Census electronic form, there was an opinion questionnaire (optional) related to some aspects of census operation. Were received 240 997 responses (4.1% of the households).

 The link between the 2021 Census and Statistics Portugal was identified by the vast majority of people who respond to the opinion questionnaire (94%) and 97% recognising that the information sent by letter to households (containing the codes and information on how to respond to the 2021 Census) has been sufficient for this purpose.

 The 2021 Census questionnaire proved to be adequate for its purpose, with 97% of respondents demonstrating that the functionalities provided for filling it in were sufficient. The figures from this opinion questionnaire also show very favourable results across the board, with the clear majority of respondents indicating that the questionnaire was easy to respond and there were no difficulties in answering the questions on "Dwellings" (98%), "Individuals" (96%) and "Households" (97%)

12.3. Completeness

The Regulation was fully complied. All predicted variables were observed

13.1. Accuracy - overall

There are no particular reasons for data unreliability 

13.1.1. Overall accuracy - Usual residence

There are no particular reasons for data unreliability for this topic

13.1.2. Overall accuracy - Sex

There are no particular reasons for data unreliability for this topic

13.1.3. Overall accuracy - Age

There are no particular reasons for data unreliability for this topic

13.1.4. Overall accuracy - Marital status

There are no particular reasons for data unreliability for this topic

13.1.5. Overall accuracy - Family status

There are no particular reasons for data unreliability for this topic

13.1.6. Overall accuracy - Household status

There are no particular reasons for data unreliability for this topic

13.1.7. Overall accuracy - Current activity status

There are no particular reasons for data unreliability for this topic

13.1.8. Overall accuracy - Occupation

There are no particular reasons for data unreliability for this topic

13.1.9. Overall accuracy - Industry

There are no particular reasons for data unreliability for this topic

13.1.10. Overall accuracy - Status in employment

There are no particular reasons for data unreliability for this topic

13.1.11. Overall accuracy - Place of work

There are no particular reasons for data unreliability for this topic

13.1.12. Overall accuracy - Educational attainment

There are no particular reasons for data unreliability for this topic

13.1.13. Overall accuracy - Size of the locality

There are no particular reasons for data unreliability for this topic

13.1.14. Overall accuracy - Place of birth

There are no particular reasons for data unreliability for this topic

13.1.15. Overall accuracy - Country of citizenship

There are no particular reasons for data unreliability for this topic

13.1.16. Overall accuracy - Year of arrival in the country

There are no particular reasons for data unreliability for this topic

13.1.17. Overall accuracy - Residence one year before

There are no particular reasons for data unreliability for this topic

13.1.18. Overall accuracy - Housing arrangements

There are no particular reasons for data unreliability for this topic

13.1.19. Overall accuracy - Type of family nucleus

There are no particular reasons for data unreliability for this topic

13.1.20. Overall accuracy - Size of family nucleus

There are no particular reasons for data unreliability for this topic

13.1.21. Overall accuracy - Type of private household

There are no particular reasons for data unreliability for this topic

13.1.22. Overall accuracy - Size of private household

There are no particular reasons for data unreliability for this topic

13.1.23. Overall accuracy - Tenure status of households

There are no particular reasons for data unreliability for this topic

13.1.24. Overall accuracy - Type of living quarter

There are no particular reasons for data unreliability for this topic

13.1.25. Overall accuracy - Occupancy status

There are no particular reasons for data unreliability for this topic

13.1.26. Overall accuracy - Type of ownership

There are no particular reasons for data unreliability for this topic

13.1.27. Overall accuracy - Number of occupants

There are no particular reasons for data unreliability for this topic

13.1.28. Overall accuracy - Useful floor space

There are no particular reasons for data unreliability for this topic

13.1.29. Overall accuracy - Number of rooms

There are no particular reasons for data unreliability for this topic

13.1.30. Overall accuracy - Density standard (floor space)

There are no particular reasons for data unreliability for this topic

13.1.31. Overall accuracy - Density standard (number of rooms)

There are no particular reasons for data unreliability for this topic

13.1.32. Overall accuracy - Water supply system

There are no particular reasons for data unreliability for this topic although the results are based on previous censuses

13.1.33. Overall accuracy - Toilet facilities

There are no particular reasons for data unreliability for this topic although the results are based on previous censuses

13.1.34. Overall accuracy - Bathing facilities

There are no particular reasons for data unreliability for this topic although the results are based on previous censuses

13.1.35. Impact of the COVID pandemic on data accuracy

No impact of data accuracy due to COVID-19

13.2. Sampling error

Not applicable, since the survey is a traditional censuses.

13.3. Non-sampling error

Not applicable.

14.1. Timeliness

The first results of the 2021 census (preliminary data) were published up to 4 months after the census (july 2021). The preliminary nature of these first results stems from the fact that they are based on counts resulting from the process of collecting observation units and are released before the process of processing and validating the information collected.

Provisional results where made available up to 10 months after the census date (december 2021). There are product of an intermediate stage in the process of processing and validating the information, and comprises a limited set of tables down to the geographical level of municipality or parish.

The final results of the 2021 Census were released after the complete processing and validation of all data, up to 19 months after the census (november 2022).

The difference between the release of preliminary and final data results is justified by the difference in the variables made available at each moment and the respective degree of processing and validation of the information.

Hypercubes were release according to Regulation EU 2017/712, between 25 and 27 march 2024.

14.2. Punctuality

Zero days

The census data where delivery just in the time. There are no difference between census delivery and the target date when it should have been delivered.

15.1. Comparability - geographical

There are no national practices which could impair the EU-wide comparability

15.1.1. Geographic information - data quality

There are no problems of comparability between regions of country 

15.2. Comparability - over time

Not applicable.

15.3. Coherence - cross domain

There are no problems.

15.4. Coherence - internal

There are no inconsistencies between the datasets defined in Commission Regulation UE 2017/712.

The cost of carrying out the 2021 Census was 36.5 million euros, considering all the costs of the statistical operation between 2016 and 2022.

The most significant part of the cost, representing 87.9% of total expenditure, is related to fees for fieldwork: enumerators and all the fieldwork interveners.

Advertising and the communication campaign (5.3%), was the second most important item in total costs, followed by specialized work (3.9%), which includes application development services and the outsourced helpline.

The COVID-19 pandemic had an impact on the operation's costs, with the need to reinforce the budget for the purchase of Personal Protective Equipment for the entire fieldwork personnel and to reinforce the helpline and telephone response.

17.1. Data revision - policy

Under the dissemination plan for the 2021 Census, the results were made available in three stages:

• Preliminary results, available in July 2021
• Provisional results, available in December 2021
• Definitive results, available in November 2022

The thinking behind this model for dissemination of the census results made it possible to bring forward the availability of the census figures for a series of variables before completion of the data-processing procedure, thus being able to meet the users' principal needs. The information disseminated was already sufficiently coherent when it was made available.. Furthermore, the results for any given stage replaced those made available during the stage immediately prior.

17.2. Data revision - practice

No revisions to report for the statistical process.

18.1. Source data

Census data are based on a total enumeration.

18.1.1. List of data sources

Census questionnaires.

18.1.1.1. List of data sources - Data on persons

Census questionnaires.

18.1.1.2. List of data sources - Data on households

Census questionnaires.

18.1.1.3. List of data sources - Data on family nuclei

Census questionnaires.

18.1.1.4. List of data sources - Data on living quarters

Census questionnaires.

18.1.1.5. List of data sources - Data on conventional dwellings

Census questionnaires.

18.1.2. Classification of data sources

Classification of the data sources according to Article 4(1) of Regulation (EC) No763/2008.

18.1.2.1. Classification of data sources - Data on persons

01.Conventional censuses

18.1.2.2. Classification of data sources - Data on households

01.Conventional censuses

18.1.2.3. Classification of data sources - Data on family nuclei

01.Conventional censuses

18.1.2.4. Classification of data sources - Data on living quarters

01.Conventional censuses

18.1.2.5. Classification of data sources - Data on conventional dwellings

01.Conventional censuses

18.1.3. List of data sources per topic

Census questionnaires.

18.1.4. Adequacy of data sources

The 2021 Census meet all the essential features of the population and housing census as request as the Regulation 763/2008.

18.1.4.1. Adequacy of data sources - Individual enumeration

Information on each enumerated person and each living quarters were obtained so that their characteristics can be separately recorded.

This allows cross classifying the various characteristics and obtaining data by more than one characteristic.

18.1.4.2. Adequacy of data sources - Simultaneity

Information obtained on individuals and housing refers to a well defined and unique or specific moment in time (reference date) – 19 April 2021.

18.1.4.3. Adequacy of data sources - Universality within the defined territory

Data are provided for all statistical units in a defined territory (for persons in particular, data are provided for all usual residents in a defined territory).

Census Questionnaires were made available for 11 foreign languages. Foreign languages were selected and translated with the support of the High Commission for Migration.

18.1.4.4. Adequacy of data sources - Availability of small-area data

Data are available for small geographical areas and for small subgroups of statistical units.

 All areas were properly covered

18.1.4.5. Adequacy of data sources - Defined periodicity

Data on population and housing censuses are collected every decade, in the year ended by 1 

18.2. Frequency of data collection

Decennial.

18.3. Data collection

The 2021 Census were carried out through an exhaustive survey, involving all persons residing in the country.

18.3.1. Data collection - Questionnaire based data

The 2021 Census was carried out through an exhaustive survey of the population, using an information collection process predominantly through internet, a strategy appropriate to the epidemiological context experienced in the country and which allowed to guarantee the quality of the information collected.

As part of the preparatory work for the 2021 Census, the testing program was essential to ensure and guarantee its successful completion, having been carried out three times: in 2016, 2018 and 2020. The objectives of the initial tests were centered essentially in evaluating the methodology recommended for these Censuses and their impact on the operation. The last test, carried out in November 2020, had the main objective of testing the collection processes that supported the census operation, namely the computer applications. The public health safety protocol has already been applied defined in light of the then-existing epidemiological context.

To support the carrying out of the 2021 Census, two sets were created of national geographic data: the Geographic Reference Base of Information – BGRI2021 and the Geographic Base of Buildings – BGE2021

The collection procedures took place over 3 phases:

Phase I - Recognition of the land by enumerators; filling in the building questionnaire; distribution of letters with codes for response online.

Phase II - Population response

Phase III – Follow up by the enumerators to guarantee that all persons complete the census response.

The response to the Censuses was possible through the following response modes:

• eCensus – electronic form for direct response by the population through Internet; Available on multiplatforms: PC, tablet and smartphone;
• eBalcão – available in Parish Councils and with support for citizens in response to Censuses;
• eEnumerator – application to support the function of the enumerator, which allowed response with the support of the census taker;
• Paper questionnaire;
• Response by telephone, via the citizen support line

In the 2021 Census, high electronic response rates were achieved (99.3%), with 87.5% of responses to be given by the population through eCensus, 7.7% through from eEnumerator and 4.1% through eBalcão. The answer through questionnaires in paper or through the telephone helpline were residual, with values ​​of 0.3% and 0.4% respectively

Annexes:
Individual Questionnaire
Private household and dewlling questionnaire

18.3.2. Data collection - Register based data

Not applicable.

18.3.3. Data collection - Sample survey based data

Not applicable.

18.3.4. Data collection - Data from combined methods

Not applicable.

18.4. Data validation

After the collection was completed, the data validation phase began. The collected data were subject to a set of validations whose objective was to ensure the consistency of the information

Various types of rules were defined:

• Rules applied to identify responses falling outside the range of values considered acceptable for the question;
• Rules to identify inconsistencies resulting from the incorrect completion of variables;
• Rules to define situations where the responses are inconsistent compared to other responses within the same statistical unit (intra-register rules) or by comparison to other statistical units (inter-register rules).

In addition the information processing process included the incorporation and taking advantage of the administrative information available at SP, particularly in the scope of SP National Data Infrastructure, particularly at the level of data validation system, non-response imputation and consistency analysis, thus contributing to reinforcing the quality of census results.

18.5. Data compilation

Between the collection of the questionnaires and the dissemination of the results, the data from the 2021 Census were subject to a series of treatment processes:

Processing - Integration of data, from different collection sources for subsequent processing. In the processing phase, the collected data was subjected to a set of validations whose objective was to ensure the consistency of information. The coding of the open questions was supported by tables, dictionaries and intelligence algorithms artificial materials specifically developed for this purpose.

Automatic corrections - a set of deterministic rules was applied to correct inconsistencies detected during the information validation phase.

Due to the high response rate via the internet, in which all responses were mandatory, only few imputations were made by deterministic imputation. 

Derived variables and specialisation - during this phase the derived variables resulting from the combination of information from one or more primary variables were calculated. 

18.6. Adjustment

Not applicable.

No comments.

Further qualitative metadata on the 2021 Population and Housing Census

The data present the results of the 2021 EU census on population and housing, following Regulation (EC) 763/2008; Regulation (EU) 2017/543; Regulation (EU) 2017/712 and Regulation (EU) 2017/881.

26 June 2024

The information is given separately for each census topic.

The EU programme for the 2021 population and housing censuses includes data on persons, private households, family nuclei, conventional dwellings and living quarters.

The persons enumerated in the 2021 census are those who were usually resident in the territory of the reporting country at the census reference date.

Usual residence means the place where a person normally spends the daily period of rest, regardless of temporary absences for purposes of recreation, holidays, visits to friends and relatives, business, medical treatment or religious pilgrimage

Data are available at different levels of geographical detail in EU countries: national, NUTS2/NUTS3, regions and local administrative units (LAU) and grids.

See the following sub-concepts.

There are no particular reasons for data unreliability 

Counts of statistical units should be expressed in numbers and where is needed rate per inhabitants enumerated in the country.

Between the collection of the questionnaires and the dissemination of the results, the data from the 2021 Census were subject to a series of treatment processes:

Processing - Integration of data, from different collection sources for subsequent processing. In the processing phase, the collected data was subjected to a set of validations whose objective was to ensure the consistency of information. The coding of the open questions was supported by tables, dictionaries and intelligence algorithms artificial materials specifically developed for this purpose.

Automatic corrections - a set of deterministic rules was applied to correct inconsistencies detected during the information validation phase.

Due to the high response rate via the internet, in which all responses were mandatory, only few imputations were made by deterministic imputation. 

Derived variables and specialisation - during this phase the derived variables resulting from the combination of information from one or more primary variables were calculated. 

Census data are based on a total enumeration.

Decennial

The first results of the 2021 census (preliminary data) were published up to 4 months after the census (july 2021). The preliminary nature of these first results stems from the fact that they are based on counts resulting from the process of collecting observation units and are released before the process of processing and validating the information collected.

Provisional results where made available up to 10 months after the census date (december 2021). There are product of an intermediate stage in the process of processing and validating the information, and comprises a limited set of tables down to the geographical level of municipality or parish.

The final results of the 2021 Census were released after the complete processing and validation of all data, up to 19 months after the census (november 2022).

The difference between the release of preliminary and final data results is justified by the difference in the variables made available at each moment and the respective degree of processing and validation of the information.

Hypercubes were release according to Regulation EU 2017/712, between 25 and 27 march 2024.

There are no national practices which could impair the EU-wide comparability

Not applicable.