The year 2011 is the peak census year of the 2010 World Programme on Population and Housing Censuses. Census is scheduled to be held in 73 countries or areas this year. By the end of the census round, it is estimated that 98% of the world’s population will have been counted. See the census dates in the table.
Census dates in the World
The Population and Housing Census represents one of the pillars for acquiring necessary data concerning the number and characteristics of the population and households and the of the housing standard in each country. For small geographical areas or subpopulations it can be the only source of information on their social, demographic and economic characteristics.
The first censuses date back at least 6 000 years ago as proven by clay platelets found in ancient Babylon. The history of contemporary censuses began in the mid of 17th century. Censuses originally represented only the enumeration of people. In the course of time, content and scope of the censuses extended and included not only basic demographic characteristics, but also more and more information concerning social and economic life.
This involves new requirements for incorporating of additional questions into the census. Census had originally military (to determine the number of men capable of military service) and fiscal significance (monarchs gained taxes collected by suzerain according to the number of their subordinates).
Inclusion of too many questions in the Census form may cause confusion and could lead to lower quality of completed data. The censuses should be organized at regular intervals in order to constitute data series comparable in time. It is recommended to carry out the census at least once every 10 years.
The Population and Housing Census is an integral part of the official statistics system in each country; one can therefore expect the census to include basic principles of official statistics. Not only individual countries participate in the preparation of censuses but also a range of international organizations.
International organizations and fundamental documents
The fundamental document for the preparation of censuses around 2010 throughout the world has bee
"Principles and Recommendations for Population and Housing Censuses, Rev. 2" issued by the UN in 2008.
The document "Conference of European Statisticians Recommendations for the 2010 Censuses of Population and Housing" was created for the region of the United Nations Economic Commission for Europe (UNECE) countries. This material was prepared in the years 2004 to 2006 in collaboration with the Conference of European Statisticians (CES), The United Nations Centre for Human Settlements – Habitat (UNCHS-Habitat) and Eurostat (The Statistical Office of the European Communities). Most European countries participated, including the Czech Republic. The recommendations define the basic principles and methods of the census and include a list of proposed indicators (with their definitions and classifications) to be incorporated into the programs of national censuses. The overview of the recommended indicators has been divided into two principal domains (main and supplementary topics):
- It is expected that main topics will be included in the Census as much as possible. The objective is to achieve representative and methodically comparable data to enable an international comparison of countries;
Additional indicators are then derived from interrelationships among these indicators.
Despite strong effort of international organizations, not all countries respect these recommendations. For this reason data of individual countries are not always comparable. Some countries or institutions including the already-mentioned UNECE and Eurostat assist countries with less advanced statistical system or those with unstable political backgrounds.
The objective of censuses in all countries is to achieve the best and most complex data as possible. Due to local conditions, there are various methods of carrying out the census in individual countries. In the last few years, several new methods of censuses appeared mainly based on new technologies. The new technologies can significantly contribute to decreasing costs and improving the quality of the census; although at the beginning the costs could raise.
- The traditional method of universal census based on data collection in the terrain at a specific time. Either all indicators in detail or only basic ones are collected; and determined indicators are collected selectively (long and short forms) more
- The traditional census with every-year updates of indicators based on sample survey;
- Using of registers and other administrative sources more
- Combination of registers and other traditional methods;
- Combination of registers, other administrative sources and other surveys (sample surveys) more
- A so-called “Rolling” Census more
The results of the processed questionnaires relating to Population and Housing Census preparation sent by UNECE member countries in spring 2004, demonstrate a shift from traditional censuses approach used during the last Census around 2000. The share of administrative registers, either as the only source of data or completed with information from questionnaires or sample surveys is being increased. A traditional Census around 2010 is being planned by ten of countries less than in the past.
The 2011 Population and Housing Census in the Czech Republic will be carried out by the traditional self-census method using data from registers (Central Population Register and Register of Enumeration Districts and Buildings). Census commissioners will deliver and collect the printed census forms. For the next Census, the Czech Statistical Office chose the subcontracting alternative when the most of fieldwork including logistic support will be assured by the subcontractor and only a small part by the Census bodies of the Czech Statistical Office. Electronic forms will be made accessible on www.scitani.cz.
Traditional (so-called Classical) Population Census
is being used by most countries. Data are usually recorded in census forms. There are two principal ways of recording:
by census commissioners, who record the answers of respondents
by the self-census, as known in the Czech Republic - i.e. recording in the Census form by the respondents themselves. Some countries use postal services for distributing the forms; the forms can be then returned in the same way.
By creating of short and long version of the census forms can be achieved reduction of the administrative burden of respondents. The short form contains only questions intended for nation-wide coverage, while the long form is to be completed only for selected dwellings, households or inhabitants and contains usually detailed questions focused on a specific topic (e.g. fertility of women or property relations). Using long and short forms helps gather more information and decrease costs at the same time. Both types of forms are distributed simultaneously.
- providing a view for the entire population in a certain period of time and data accessibility for the smallest geographical units as possible;
- carrying out the Census by the census commissioner is the only way of collecting data that can be used when contacting illiterate citizens or other groups of citizens unable themselves to complete the census forms.
- more complicated than using data from registers, more difficult and expensive;
- this method requires full awareness and assistance of the public;
- due to its complexity and expensiveness, censuses are usually carried out once every five or ten years. For this reason the last available census data are several years old.
Registers and other administrative sources
represent an alternative to traditional censuses, as they contain relevant topics, use similar definitions and classifications and cover the entire population. This method is often supplemented by traditional censuses. The Census when using registers is based on a set of fundamental registers, which contain complex data on census units.The most common registers are the following: Central Population Register; Birth, Deaths and Marriage Register; Czech Office for Surveying, Mapping and Cadastre; Register of Tax-payers; Business Register; Labour Force Register; Register of Unemployed Persons; Register of Social Insurance Payers, Pensioners and Disabled Persons; Address Register; Health Register and others.
The development of a registers system, which would be appropriate for the Population Census, is usually a long-term process and can take several years or even decades. During this transitional period it is still necessary to use the traditional method of the census until it is possible to fully transform to using the registers. The first data taken from registers are usually addresses, basic demographic data and information about residence registration of a given person in respective country. The share of administrative data generally increases from the census to the census. The key factor is including of a common identification number for person and his place of residence in order to allow interconnection of data from different administrative sources (in the Czech Republic this is the personal identification number and non-semantic identifiers for addresses of residencies). The next Census in most European Union countries will be carried out in this transitional period.
Legal enactments specify an important basis for using of administrative data sources for statistical purposes. This type of legislation provides statistical offices the authority to access individual records of registers and with the aid of identification data their interconnection. Beyond this, the respective legal enactments shall provide a detailed delimitation of data protection.
Especially Scandinavian countries (Iceland, Sweden, Denmark, Finland and Norway) and the Netherlands have long-term experiences with using of registers for censuses. Austria and Slovenia will start using registers in the next Census in 2011. In our country we presume only the utilization of some data for pre-filling the forms. This option is included in Act No. 296/2009 Coll. concerning the Population and Housing Census in 2011.
- using of administrative sources decreases the costs of the census;
- information is gathered only once; only data changed from the previous census are processed;
- important statistics collected by traditional way, soon become out-of-date between individual censuses (e.g. statistics of employment). By using this census model, up-to-date/current/actual statistics can be available every year.
- Census based on registers may only contain information accessible in registers;
- register must be updated regularly, which can sometimes be problematic;
- registers must reflect all changes in legal enactments and administrative procedures;
- there threatens a possibility of greater misusing of data.
alone cannot provide data corresponding census sufficiently but can be used in combination with a Population Census or can provide additional information on certain topics. Some countries produce statistics data type of Population and Housing Census by using data from registers and other administrative sources together with data from sample surveys.
This option is used for example in the Netherlands and is appropriate for those countries that do not have all census data included in available registers. If this option is selected, some census outputs could be compiled by using data from registers only, whereas some outputs must be compiled by completing from survey results and applying them to the entire population.
- Censuses based on combination of sample surveys and registers are much cheaper than carry out a census of the entire population.
- when using data from sample surveys there is not possible to achieve reliable outputs for small territorial units, e.g. districts or municipalities;
- it may be difficult to achieve public awareness about the census and using of its results if the sample survey is realized only after the census.
is a method presently being used only in France. This method represents an alternative approach to the traditional model of the Population Census. With the help of continuous survey when only a part of population is being surveyed successively, it is possible to collect current data for longer period of time, and not only at the decisive moment, as it is the case of traditional censuses.
- higher frequency of data updates (but only for a part of the territory; this is impossible for the whole country);
- partial reduction of the burden towards the public.
- does not content census of the entire population at the decisive moment, which complicates interregional comparison due to collection of data at different times.
Collection of data
With respect to the maturity of the statistical system in a given country, public opinion concerning personal data disclosure and communication technology penetration, the method of data collection is chosen. In principle there are used four methods of data collection; they can be used separately or in combination:
- The most common way of collecting data in the terrain is the collection of census forms in households by the census commissioners (forms are completed by households’ members themselves, “so called self-census” or by census commissioners). In some countries the census commissioner collects data with help of portable computers. For example pocket computers - PDAs (Personal Digital Assistant) will be used in the 2010 Census in Oman, and in Poland laptops (about 20 000 pieces) will fully replace census forms. Concerning manual equipment, there could appear a range of operational (battery life) and security problems. When using this method of collection there threatens much larger risk of theft or loss in comparison to paper forms. For this reason it is essential to backup the data regularly. It is also essential to protect all data confidentiality not only in the case of equipment theft, but also during data transmission. Data in portable computers should be encrypted and accessible through password only.
- Through postal services, it is possible to send the completed forms by registered post or by way of a census commissioner. Advantage of lower costs is evident, but the quality of completion is then impossible to check.
- The method of Internet connection (e-census) is considered to be self-census. A key factor is to check the collection and the quality of the completed forms. This method enables to add groups of citizens that are difficult to add by traditional collection method (e.g. young people or persons that would rather avoid the commissioner’s visit in their domicile). This would mean that each household and each individual would have their own code, which would be interconnected to the address. The possibility of using this option should be considered by assessing the proportion of population having Internet access. When using the Internet as a method of collection, there could appear initial increase of the census costs, as it is impossible to determine the utilization of this option in advance. For this reason it is necessary to deliver paper forms to each household including those where the Internet will subsequently be used. In the long-term aspect this method of collection seems to be economical. The issue of data security when using this method is very important. Electronic form offers the option of interactive support of its completing, which improves the quality of the responses; the same is not possible to secure in printed form. For example Australia, Canada, New Zealand, Spain, Switzerland, Belgium belong to countries having experience with data collection by using the Internet. Many countries including several developing countries plan to use this method of data collection during 2010 and 2011 Censuses.
- Another method of electronic collection of forms is using of data boxes. This method together with method of completion through Internet will be used for the 2011 Population and Housing Census in the Czech Republic.
- Automatic telephone calls (real or automated operator) could represent a cost-effective solution mainly for countries using “short-form” questionnaires which record only basic information on demography, households and families. Again, in this case each household must be provided with unique code which enables checking collection of data. The respondent can be guided when completing the census form either by way of voice recognition or by way of telephone keypad. The popularity of this system significantly decreases due to rising number and complexity of questions, as well as to increasing number of households’ members. Some people are sceptical to providing confidential data by telephone; they do not like this impersonal method of communication.
Would you like to know more about censuses abroad?
The World Population and Housing Census Programme is a centre for the support of international exchange of experience and information related to Population Census. The website provides activity reports connected with the Census around 2010. It contains information on the meetings and seminars organized by the UN’s Statistical Division and other respective organizations. The most beneficial part is the Census Knowledge Base, which serves as a storage site for documents concerning the methodology of Population Censuses. Also included is a Newsletter being issued approximately every three months. It provides information not only on seminars and meetings already undertaken, but mainly information on upcoming and already realized censuses in various countries. Worth mentioning is also the time schedule of censuses in countries throughout the world along with a general map.