Statistics Portugal Information
How is it obtained?
Statistics Portugal information is obtained from:
- Exhaustive surveys (censuses),in which every item from a given population is subject to observation: Population and Housing Censuses, and Agricultural Census.
- Sample surveys, in which data are collected from a sample representing the population under observation. The calculation process resorts to statistical methods in order to extrapolate data resulting from the sample survey of the population in study;
- Administrative sources, in which data stemming from administrative procedures are used for statistical purposes.
Statistics Portugal’s surveys may cover variables for definitions in quantitative terms (replies requested with reference to volume) or in qualitative terms (replies requested with reference to opinions/views).
Who replies to Statistics Portugal's Surveys
- Organisations (of the public and private sector, corporations, associations, central and local government, etc.);
- Citizens selected by Statistics Portugal and previously informed in writing.
How is the reporting agent selected
As regards most surveys (excluding the censuses) the selection of organisations and citizens is based on sampling.
In the case of organisations the selection is made from the Statistics Portugal’s database (Statistical Units Register) which contains information, inter alia, on enterprises and establishments, sole proprietorships, associations, and local, regional and general government bodies. This database – the most extensive in the country, with more than a million records – is built up from registers received from business official registries. It is updated from different sources, among which tax data, business registration codes and Statistics Portugal own surveys.
In the case of citizens the selection is based on the so-called Master sample, a sub-group of 500,000 households taken from the census database. This database comprises information reported by the citizens themselves in the population and housing censuses.
Reply is mandatory
Any reporting required by Statistics Portugal in the exercise of its functions and in the framework of the statistical authority conferred on it by law, shall be mandatory and free of charge.
How to reply to Statistics Portugal
In the case of organisations the reply may be sent:
- by post, returning to Statistics Portugal the questionnaires duly filled-in, in the envelope provided for the purpose;
- electronically, through the services mentioned on this website.
Citizens are requested to reply:
- by direct interview, at home, by duly identified interviewers of Statistics Portugal;
- by filling-in the questionnaires left at home (with the support of the interviewer).
- by telephone, gradually covering a higher number of statistical operations.
Results disseminated by Statistics Portugal
- Primary statistics – obtained from the treatment of replies to the different surveys to organisations and citizens;
- Economic variables and population Derivate statistics estimates;
- Demographic projections;
- Studies on demographic, social or economic phenomena.
The results are made available in different ways – according to the announced Calendar – particularly in the “Press Releases” sent to the media and simultaneously released on this website and to on-linesubscribers.
Most of the information released by Statistics Portugal is available on-line. Part of it is also issued in publications.
Dissemination depends on the frequency of the statistical operations: monthly, quarterly, half-yearly, yearly, five-yearly, ten-yearly or occasionally in the case of studies.