Census

A census is the process of obtaining information about every member of a population (not necessarily a human population). The term is mostly used in connection with national 'population and housing censuses' (to be taken every 10 years according to United Nations recommendations); agriculture censuses (all agriculture units) and business censuses (all enterprises).

The census can be contrasted with sampling in which information is only obtained from a subset of a population. As such it is a method used for accumulating statistical data, and also plays a part in democracy (voting). Census data is also commonly used for research, business marketing, planning purposes and not at least as a base for sampling surveys.

It is widely recognized that population and housing censuses are vital for the planning of any society. Traditional censuses are however becoming more and more costly. A rule of thumb for census costs in developing countries have for a long time been 1 USD / enumerated person. More realistic figures today are around 3 USD. These approximates should be taken with great care since a various amount of activities can be included in different countries (e.g. enumerators can either be hired or requested from civil servants). The cost in developed countries is far higher. The cost for the 2000 census in the US is estimated to 4.5 billion USD. Alternative possibilities to retrieve data are investigated. Nordic countries Denmark, Finland and Norway have for several years used administrative registers. Partial censuses ‘Micro censuses’ or ‘Sample censuses' are practiced in France and Germany.

Census and privacy
While the census provides a useful way of obtaining statistical information about a population, such information can sometimes lead to abuses, political or otherwise, made possible by the linking of individuals' identities to anonymous census data.

It is not unusual for census data to be processed in some way so as to obscure individual information. Some censuses do this by intentionally introducing small statistical errors to prevent the identification of individuals in marginal populations; others swap variables for similar respondents.

Whatever measures have been taken to reduce the privacy risk in census data, new technology in the form of better electronic analysis of data pose increasing challenges to the protection of sensitive individual information.

Ancient and medieval censuses
The first known census was taken by the Babylonians in 3800 BC, nearly 6000 years ago. Records suggest that it was taken every six or seven years and counted the number of people and livestock, as well as quantities of butter, honey, milk, wool and vegetables.

One of the earliest documented censuses was taken in 500-499 BC by the Persian Empire's military for issuing land grants, and taxation purposes.

Censuses were conducted in the Mauryan Empire as described in Chanakya's (c. 350-283 BC) Arthashastra, which prescribed the collection of population statistics as a measure of state policy for the purpose of taxation. It contains a detailed description of methods of conducting population, economic and agricultural censuses.

The Bible relates stories of several censuses. The Book of Numbers describes a divinely-mandated census that occurred when Moses led the Israelites from Egypt. A later census called by King David of Israel, referred to as the "numbering of the people," incited divine retribution (for being militarily motivated or perhaps displaying lack of faith in God). A Roman census is also mentioned in one of the best-known passages of the Bible in the Gospel of Luke, see Census of Quirinius.

Rome conducted censuses to determine taxes (see Censor). The word 'census' origins in fact from ancient Rome, coming from the Latin word 'censere', meaning ‘estimate’. The Roman census was the most developed of any recorded in the ancient world and it played a crucial role in the administration of the Roman Empire. The Roman census was carried out every five years. It provided a register of citizens and their property from which their duties and privileges could be listed.

The world's oldest extant census data comes from China during the Han Dynasty. Taken in the fall of 2 AD, it is considered by scholars to be quite accurate. At that time there were 59.6 million living in Han China, the world's largest population. The second oldest preserved census is also from the Han, dating back to 140 AD, when only a bit more than 48 million people were recorded. Mass migrations into what is today southern China are believed to be behind this massive demographic decline.

In the Middle Ages, the most famous census in Europe is the Domesday Book, undertaken in 1086 by William I of England so that he could properly tax the land he had recently conquered. In 1183, a census was taken of the crusader Kingdom of Jerusalem, to ascertain the number of men and amount of money that could possibly be raised against an invasion by Saladin, sultan of Egypt and Syria.

A very interesting way to record census information was made in the Inca Empire in the Andean region from the 15th century until the Spaniards conquered their land. The Incas did not have any written language but recorded information collected during censuses and other numeric information as well as non-numeric data on quipus, strings from llama or alpaca hair or cotton cords with numeric and other values encoded by knots in a base 10 positional system.

Afghanistan
A partial and incomplete population census was taken in Afghanistan in 1979. A census is planned for 2007.

Algeria
Population and housing censuses have been carried out in Algeria in 1967, 1977, 1987 and 1997.

Antigua & Barbuda
A Population & Housing Census was carried out in 2001

Argentine
National population census are carried out in Argentina roughly every ten years, the last one being in 2001.

More about census, see: National Institute of Statistics and Census of Argentina

Austria
The Austrian census is run by the Statistik Austria. It is carried out every ten years, the last on being in 2001.

Australia
The Australian census is operated by the Australian Bureau of Statistics. It is currently conducted every five years, the last occurrence being on August 8, 2006. Past Australian censuses were conducted in 1911, 1921, 1933, 1947, 1954, 1961, 1966, 1971, 1976, 1981, 1986, 1991, 1996, 2001 and 2006. In 2006, for the first time, Australians were able to complete their census online.

Bangladesh
Population censuses have been carried out in 1974, 1981, 1991 and 2001. It is done by the Bangladesh Bureau of Statistics (BBS)

Benin
Population censuses have been taken in Benin in 1978, 1992 and 2002

Bolivia
Population and housing censuses have been carried out in Bolivia in 1992 and 2001.

Bosnia-Herzegovina
A census was taken by apostolic vicar the bishop Pavao Dragicevic in 1743.

Brazil
The Brazilian census is carried out by IBGE, the Brazilian Institute of Geography and Statistics, every 10 years. The last one was in 2000. Earlier censuses were taken in 1872 (the first), 1900, 1920, 1941, 1950, 1960, 1970, 1980 and 1991.

Bulgaria
The first census was organised after Bulgarian parliament passed a law for national censuses in 1880. A special Act on Statistics was enacted in 1897. It was following on the edge European standards at the time. The area of the next census was widening for the purposes of International Statistical Institute which was planning a world wide census of the then ‘civilized world’ at the time. The Directorate of Statistics was the only institution authorized and responsible with and for organization and of national censuses. The procedure remained the same until WW-II.

During the period in review Bulgaria has organized 16 population censuses (1880, 1884, 1887, 1892, 1900, 1905, 1910, 1920, 1926, 1934, 1946, 1956, 1965, 1975, 1985, 1992 all of them ending in December and 2001 providing data by March same year). Reliability of the statistics, indeed, improved with the time.

The information in the first censuses covers a wide range of data: •	Population statistic – sex, age, nationality, mother tongue, education, religion, different groups of disabled people •	Occupation…. •	Animal statistics- providing detailed information on the number of beasts on the village and town level; •	Dwelling statistics – the data is broken down by villages/towns and by type of use – for living and for rent providing purposes •	Vital statistics – marriage, number of family members, age at marriage, mortality and nativity

Canada
The Canadian census is run by Statistics Canada. The first census conducted in Canada was conducted in 1666, by French intendant Jean Talon, when he took a census to ascertain the number of people living in New France. The individual provinces conducted censuses, in the 19th century and before, sometimes in conjunction with each other. In 1871, Canada's first formal census was conducted, which counted the population of Nova Scotia, Ontario, New Brunswick, and Quebec. In 1918, the Dominion Bureau of Statistics was formed, and replaced by Statistics Canada in 1971.

Censuses in Canada are conducted in five-year intervals. The last two censuses were conducted in 2001 and 2006. Censuses taken in mid-decade (1976, 1986, 1996, etc.) are referred to as quinquennial censuses. Others are referred to as decennial censuses. The first quinquennial census was conducted in 1956.

For the 2006 Census of Canada, respondents were able, for the first time, to choose to complete their census questionnaire online. Other options for answering the questionnaire include postal mail (using a pre-paid envelope) and telephone (using a 800 number).

See also: Canada 2001 Census, Canada 2006 Census.

Alberta

In the Province of Alberta, Section 57 of its Municipal Government Act (MGA) enables municipalities to perform their own censuses on any given year. An official municipal census must be conducted no earlier than April 1 and no later than June 30 of the same year, according to the MGA's Determination of Population Regulation. If municipalities choose to make their census count official, the new population must be submitted to the Ministry of Municipal Affairs and Housing prior to September 1 of the year the census was performed. The latest census counts for Alberta's municipalities are released in the Ministry's annual Official Population List publication.

AltaPop (Alberta Population) is a very useful website that builds upon the data provided by the Province and Statistics Canada. Visit AltaPop to compare municipal and federal census results by municipality, to analyse historic population trends by municipality, and to view detailed annual population summaries either by size of municipality or sorted alphabetically.

China
Population censuses have been taken in the People's Republic of China in 1953, 1964, 1982, 1990 and 2000. Theses are the world's biggest censuses as they attempt to count every man, woman and child in its colossal population. Some 6 million enumerators were enganged in the 2000 census. An first economic census was taken in 2004.

Costa Rica
Costa Rica carried out its 9th population census in 2000. INEC, National Institute of Statistics and Census is in charge of conduct these census. Past Costa Rican censuses were conducted in 1864, 1883, 1892, 1927, 1950, 1963, 1973 and 1984.

Czech Republic
Census in the Czech Republic is carried out every 10 years by the Czech Statistical Office. The last census was taken in 2001.

Denmark
The first Danish census was in 1700-1701, and contained statistical information about adult men. Only about half of it still exists. A census of school children was taken during the 1730s.

Following these early undertakings, the first census to attempt completely covering all citizens (including women and children who had previously been listed only as numbers) of Denmark-Norway was taken in 1769. At that point there were 797 584 citizens in the kingdom. Georg Christian Oeder took a statistical census in 1771 which covered Copenhagen, Sjælland, Møn, and Bornholm.

After that, censuses followed somewhat regularly in 1787, 1801, and 1834, and between 1840 and 1860, the censuses were taken every five years, and then every ten years until 1890. Special censuses for Copenhagen were taken in 1885 and 1895.

In the 20th century, censuses were taken every five years from 1901 to 1921, and then every ten years from 1930. The last traditional census was taken in 1970.

A limited population census based on registers was taken in 1976. From 1981 and each year onwards information that corresponds to a population and housing census is retrieved from registers. Denmark was the first country in the world to conduct these censuses from administrative registers. The most important registers are the population register (Det Centrale Personregister), a Building and Dwelling Register and an Enterprise Register. The central statistical office, Statistics Denmark is responsible for compiling these data. This information is available online in the Statbank Denmark.

It is possible to search a portion of the Danish censuses online at Dansk Demografisk Database, and also view scanned versions at Arkivalier Online.

Egypt

 * The Statistical Department of the Ministry of Finance conducted the first census in 1882, which considered as a preparatory step; the first true population census was conducted in 1897. Thereafter, censuses were conducted at ten-year intervals in 1907, 1917, 1927 and so on.
 * In 2006 the Central Agency For Public Mobilization and Statistics CAPMAS conducted the thirteenth census in the Egyptian census series where the Egypt's population hit 76.5 million inside and outside the country.

Ethiopia
Three censuses have been taken in Ethiopia: 1984, 1994 and in 2007. The responsible institution is the Central Statistical Agency.

Most of the census in 2007 was taken in August, while the Somali Region and the Afar Region were not covered. The northern Afar region is a remote, hot and arid area. The eastern Somali region (Ogaden) hosts a large nomadic Somali population and is a conflict area where Ethiopian regular forces are fighting against Ogaden National Liberation Front (ONLF).

Finland
The first population census was taken in 1749 when Finland was a part of Sweden.

France
Napoleon Bonaparte began the census in France as a means of determining the number of potential soldiers under his rule. Today, the census in France is carried out by INSEE. Since 2004, a partial census is carried out every year, and the results published as averages over 5 years.

Germany
The first systematic population on the European continent was taken in 1719 in Prussia (roughly corresponding to today's northern Germany and western Poland).

The first large-scale census in the German Empire took place in 1895. Attempts at introducing a census in West Germany sparked strong popular resentment in the 1980s since many quite personal questions were asked. Some campaigned for a boycott. In the end the Constitutional Court stopped the census in 1980 and 1983. The last census was in 1987. Germany has since used population samples in combination with statistical methods, in place of a full census.

Greece
Census takes place every 10 years and is carried out by the National Statistical Service of Greece. Last census was in 2001.

Guatemala
Modern population censuses have been taken in Guatemala in 1930, 1950, 1964, 1973, 1981, 1994 and in 2002. Controversial cenuses were in particular the ones in 1950 and 1964 (misclassification of the Maya population) and the 1994 census (generally questioned).

Relaciones Geográficas of Mexico and Guatemala, 1577-1585.

On May 25, 1577, King Philip II of Spain ordered by royal cédula the preparation of a general description of Spain's holdings in the Indies. Instructions and a questionnaire, issued in 1577 by the Office of the Cronista Mayor-Cosmógrafo, were distributed to local officials in the Viceroyalties of New Spain and Peru to direct the gathering of information. The questionnaire, comprised of fifty items, was designed to elicit basic information about the nature of the land and the life of its peoples. The replies, known as "relaciones geográficas," were written between 1579 and 1585 and were returned to the Cronista Mayor-Cosmógrafo in Spain by the Council of the Indies.

Hong Kong
Census takes place every 10 years and by-census between two censuses by the Census and Statistics Department of Hong Kong. The last census was conducted in 2001 and the next by-census will take place in 2006.

Hungary
Official decennial censuses have been taken in Hungary since 1870; the latest one – in line with the recommendations of the United Nations and the Statistical Office of the European Union – was carried out in 2001. Starting from 1880 the Hungarian census system was based on native language (the language spoken at home in the early life of the person and at the time of the survey), vulgar language (the most frequently used language in the family), and other spoken languages.

Iceland
The first Icelandic census took place in 1703, following upon the first Danish census of 1700-1701. Further censuses were carried out in 1801, 1845 and 1865. The 1703 exercise was the first ever census to cover all inhabitants of an entire country, mentioning the name, age and social position of each individual. All of the information still exists, although some of the original documents have been lost.

The setting up, in 1952, of the National Register (þjóðskrá) eliminated the need for censuses. All those born in Iceland, and all new residents, are automatically registered. Individuals are identified in the register by means of a national identification number (the so-called kennitala), a number composed of the date of birth in the format ddmmyy and four additional digits, the last of which indicates the century in which the person was born (9 for the 1900s and 0 for the 2000s).

In Iceland, the National Register also doubles as electoral register. Likewise, all bank accounts are linked to the national identification of the owner (companies and institutions all have their own identification numbers).

India
The decennial census of India is the primary source of information about the demographic characteristics of the population of India which is the second biggest country of the world in terms of population.

The first census in India in modern times is dated 1872. It started as far back as in 1860 and was finished in 1871. Starting from there, a population census has been carried out every 10 years, latest being the fourteenth in February-March 2001.

Census is carried out by the office of the Registrar General and Census Commissioner, India, Delhi under the Census of India Act, 1948. The act gives Central Government many powers like to notify a date for Census, power to ask for the services of any citizen for census work. The law makes it compulsory for every citizen to answer the census questions truthfully. The Act provides penalties for giving false answers or not giving answers at all to the census questionnaire. One of the most important provisions of law is the guarantee for the maintenance of secrecy of the information collected at the census of each individual. The census records are not open to inspection and also not admissible in evidence.

Census happens in two phases, first House Listing and House Numbering Operations and second actual population enumeration phase. Census is carried out by the canvassing method. In this method, each and every household is visited and the information is collected by a specially trained enumerator.

9 February 2001, the first day of the 2001 census was celebrated as the census day.

Source

 * Website of the office of the Registrar General and Census Commissioner, India
 * Banthia J.K., Ex Registrar General & Census Commissioner, India. "Mobilising Support for India’s Census - Constraints and Challenges"

Israel
The first census in Israel was held in November 1948, six months after the creation of the state. Subsequent censuses took place in 1961, 1972, 1983 and 1995. The aforementioned were conducted by the Israel Central Bureau of Statistics.

Ireland
The census in Ireland is carried out by the Central Statistics Office (Ireland). The previous two censuses were carried out in 2002 and most recently on April 23 2006. The census is carried out every five years, except in 2001, whose census was postponed to 2002 due to the outbreak of foot and mouth disease. According to the 2006 form, "any person who fails or refuses to provide information or who knowingly provides false information may be subject to a fine of up to €25,000," under the Central Statistics Act 1993.

The census in Ireland is very similar to that of the United Kingdom. That is, the "100 year" law applies here as well, as does the recent addition of a question regarding religion to the 2006 census. However, the 1911 Census for the whole of Ireland was made publicly available some time ago.

Since the very first census, the question of "Can you speak Irish?" has been asked. This has often led to misleading figures, as many people know how to speak some Irish through schooling, but do not actually speak it frequently. The 2006 census included how often you spoke the language if you had chosen the "Yes" answer if you spoke Irish.

Also, on the CSO website, instructions for non-English speaking residents of the Republic of Ireland were available. They were mock copies of the census forms, with all headings/questions etc. being translated into a particular language. These were not to be filled out, but were only a guide on how to fill out the English or Irish form.

This census also asked two unique questions relating to ownership of PCs and what Internet connection your home had. The next census will take place in the year 2011.


 * Web site of the Central Statistics Office Ireland

Italy
The census in Italy is carried out by ISTAT every 10 years. The last four were in 1971, 1981, 1991, 2001.

Japan
Japan collects census information every five years. The figures show the English translation of the 2005 census form. The form solicits information on name, sex, relationship to head of household, year and month of birth, marital status, nationality, number of members of household, type and nature of dwelling, floor area of dwelling, number of hours worked during the week prior to October 1, employment status, name of employer and type of business, and kind of work.

Jordan
The first population census after the independence in 1946 was taken in 1952. It did only count the number of people in the households and could therefore be considered only to be a housing census. The first real complete census was taken in 1961. The following censuses have been taken in 1979, 1994 and 2004. A political sensitive issue have since the Six-Day war in 1967 been the distribution of the population in Palestinians and Jordanians.

Kenya
Census in Kenya was first held in 1958, when Kenya was still a Colony administrated by the British. Since 1969 census has been taken every ten years. The last census to date was in 1999.

Kosovo
Kosovo is formally a part of Serbia but is administrated by the UN since 1999. A population census is planned under international supervision for 2007.

Latvia
The most recent census in Latvia was in 2000. Before that, it was about 6 censuses, most part of these previous censuses was in the USSR time. The census in Latvia is carried out by Centrālā Statistikas Pārvalde (Central Statistical Bureau).

Lebanon
Any census has not been taken in Lebanon since 1932.

Macedonia
The foundation of the Republic of Macedonia followed the break up of the former Yugoslav Republic in 1991. The first population and housing census was taken in the summer 1994. The second census was taken in the autumn 2002. Both censuses were observed by international experts due to the sensitive issue regarding the ethnic distribution (Macedonian vs Albanian population).

Mozambique
The first census was taken in 1980. The second in 1997. The third was taken 1-14 August 2007.

Netherlands
The first census in the Netherlands was conducted in 1795, and the last in 1971. A law was produced on April 22 1879, saying that a census be conducted every ten years.

The census that was supposed to be conducted in 1981 was postponed and later cancelled. A call for privacy was responsible for the cancellation of any further census since 1991.

New Zealand
The census in New Zealand is carried out by Statistics New Zealand (Tatauranga Aotearoa), every five years. The last was on 7 March 2006. For the 2006 Census of New Zealand, respondents could choose to complete their census questionnaire online. See New Zealand Census of Population and Dwellings.

Nigeria
Population censuses have been taken in Nigeria during colonial time in 1866, 1871, 1896, 1901, 1911, 1921 and 1952. The censuses covered only the southern part of the country except for the 1952 census which was country wide. It shall be noted that the censuses before 1921 were merely based on administrative estimates than on an actual enumeration.

Censuses during the independence were taken 1963, 1973, 1991 and 2006. The results from 1973 were highly disputed. The preliminary results for 2006 indicates a population of 140,000,000. 700,000 enumerators were engaged in this operation.

Norway
The two first male census was conducted during the 1660s and 1701. Later statistical censuses were held in 1769, 1815, 1835, 1845, and 1855. Norway’s first nominative, complete census was taken in 1801, when Norway still was ruled by the Oldenburg dynasty of Denmark-Norway. The scope of the census followed the de jure principle, so military persons should be included as well as foreigners if they were residents. The 1865, 1875 and 1900 censuses are digitized, and are made searchable on the internet. The census records are made public available when 100 years have passed. Since 1900, the census has been conducted every ten years. (However, the 1940 census was postponed to 1946.) Since 2001 the population census has been combined with the housing statistics.

Oman
Censuses have been taken in the Sultanate of Oman in 1993 and 2003.

Peru
The first census in Peru was carried out in 1836. The tenth and last one was the 2005 Census and was carried out by Instituto Nacional de Estadística e Informática. The next census will be the 2007 Census.

Poland
The census in Poland is carried out by GUS every circa 10 years - see censuses in Poland. The last one occurred in 2002.

Portugal
The first census in Portugal was carried out in 1864. The census in Portugal is carried out by INE every 10 years. The last one occurred in 2001.

Romania
The first census in Romania was carried out in 1859. Nowadays it is carried every ten years by the Institutul Naţional de Statistică (INSSE). The last one occurred in 2002.

Russia/USSR
In Russia, the first (and the only) Russian Empire Census was carried out in 1897. All-Union Population Censuses were carried out in the USSR (which included RSFSR and the other republics) in 1920 (urban only), 1926, 1937, 1939, 1959, 1970, 1979, and 1989. The first post-Soviet Russian Census was carried out in 2002. The next census is tentatively planned for 2010. Currently, the census is the responsibility of the Federal State Statistics Service.

Saudi Arabia
Population censuses have been taken in Saudi Arabia in 1962/63 (incomplete), 1974 (complete but not reliable), 1992 and 2004. An agriculture census was taken in 1999.

Serbia
The census takes place every 10 years. The last census was in 2002.

Slovenia
The first census of modern Slovenia was carried in 1991, after independence had been declared. The Statistical Office of the Republic of Slovenia (Statistični urad Republike Slovenije) conducted the second census in 2002. Further censuses are planned for every 10 years.

South Africa
The first census of South Africa was taken in 1911. Several enumerations have occurred since then, with the most recent two being carried out by Statistics South Africa in 1996 and 2001.

Spain
The census in Spain is carried out by INE every 10 years. The first modern census was carried out in 1768 by Conde de Aranda, under the reign of Carlos III. The last four were in 1971, 1981, 1991, 2001.

Sudan
Population censuses have been carried out in Sudan in 1955/56, 1973 (national), 1983 (national) and 1993 (only north). A census is planned for February 2008.

Sweden
The first population census in Sweden was carried out in 1749. The last population and housing census was carried out in 1990. It is planned to conduct population and housing censuses based on registers in the future.

Switzerland
In Switzerland, the Federal Population Census (Eidgenössische Volkszählung, Recensement fédéral de la population) has been carried out every 10 years starting in 1850. The census was initiated by Federal Councillor Stefano Franscini, who evaluated the data of the first census all by himself after Parliament failed to provide the necessary funds. The census is now being conducted by the Swiss Federal Statistical Office, which makes most results available on its website.

Data being collected include population data (citizenship, place of residence, place of birth, position in household, number of children, religion, languages, education, profession, place of work, etc.), household data (number of individuals living in the household, etc.), accommodation data (surface area, amount of rent paid, etc.) and building data (geocoordinates, time of construction, number of floors, etc.). Participation is compulsory and reached 99.87% of the population in 2000.

Starting in 2010, the census will cease to be conducted through written questionnaires distributed nationwide. Instead, data in existing population registers will be used. That data will be supplemented with a biannual questionnaire sample of 200,000 people as well as regular microcensuses.

Syria
The first population census in Syria was taken by the French Mandatory Regime in 1921-22. This is however not considered reliable. Censuses during independence have been taken 1947, 1960 (the first comprehensive demographic investigation), 1970, 1976 (a sample census), 1981, 1994 and 2004.

Turkey
The Turkish census is run by Devlet İstatistik Enstitüsü. The first census in Turkey was conducted in 1927. After 1935, it took place in every 5 years until 1990. Now, the census takes place every 10 years. The last census was in 2000. It can be noted that the census enumeration takes place on one single day in Turkey (in other countries it takes 1-2 weeks). This required some 900,000 enumerators in 2000. The 15th census based on improved geographical information systems is planned for 2010.

A census was taken in the Ottoman Empire 1831-38 by Sultan Mahmud II (1808-1839) as a part of the reform movement Tazimat. Even Christian and Jewish men were counted but no women..

Uganda
The first censuses in Uganda were taken 1911, 1921 and 1931. It was done in a rather primitive way. Enumeration unit was 'huts' and not individuals. More scientific censuses were taken 1948 and 1959 where the enumeration unit was persons. The census was however divided into two separate enumerations, one for Africans, and one for the non-African population. The censuses during independence 1969, 1980, 1991 were taken jointly for all races. The censuses 1980 and 1991 included housing information and in addition a larger questionnaire for a sample of the population. It can be mentioned that the questionnaires for the 1980 were lost and only provisional figures are available from this census. The census in 2002 involved some 50,000 enumerators and supervisors.

Ukraine
The first post-Soviet Ukrainian Census was carried out by State Statistics Committee of Ukraine in 2001, twelve years after the last All-Union census in 1989.

United Kingdom
In the 7th century, Dál Riata (now western Scotland and northern County Antrim in Ireland) was the first territory in what is now the UK to conduct a census, with what was called the "Tradition of the Men of Alba" (Senchus fer n-Alban). England took its first Census when the Domesday Book was compiled in 1086 for tax purposes.

Following the influence of Malthus and concerns stemming from his An Essay On The Principle Of Population the UK census as we know it today started in 1801. This was championed by John Rickman who managed the first four up to 1831, partly to ascertain the number of men able to fight in the Napoleonic wars. Rickman's 12 reasons - set out in 1798 and repeated in Parliamentary debates - for conducting a UK census included the following justifications:
 * 'the intimate knowledge of any country must form the rational basis of legislation and diplomacy'
 * 'an industrious population is the basic power and resource of any nation, and therefore its size needs to be known'
 * 'the number of men who were required for conscription to the militia in different areas should reflect the area's population'
 * 'there were defence reasons for wanting to know the number of seamen'
 * 'the need to plan the production of corn and thus to know the number of people who had to be fed'
 * 'a census would indicate the Government's intention to promote the public good' and
 * 'the life insurance industry would be stimulated by the results.'

The census has been conducted every ten years since 1801 and most recently in 2001. The first four censuses (1801-1831) were mainly statistical (that is, they were mainly headcounts and contained virtually no personal information).

The 1841 Census, conducted by the General Register Office, was the first to record the names of everyone in a household or institution. However, their relationship to the head of the household wasn’t noted, although sometimes this can be inferred from the occupation shown (eg servant). Those under the age of 15 had their proper ages listed, but for those who were older the ages were supposed to be rounded down to the nearest five years, although this rule was not strictly adhered to. Precise birthplaces were not given - at best the birthplace can be narrowed down to the county in which the person was living.

From 1851 onwards the census shows the exact age and relationship to the head of household for each individual; the place of birth was also listed, but with varying degrees of precision. Sometimes those who were born abroad have the annotation B.S. or British Subject.

The censuses are reasonably accurate. However, ages in particular are frequently shown incorrectly, though often the difference is only one year; in general the younger the individual the more accurate the age shown. Birthplaces often vary from one census to the next: a common error is to show the place where the census was taken as the birthplace, but most of the variations in birthplace can be accounted for by changes in geographical scale (for example, the nearest town being shown instead of the precise village, or a city being shown instead of the relevant suburb).

The censuses are also remarkably complete - though inevitably a small percentage of the population wasn’t recorded for one reason or another, and in some cases the records are missing or damaged (notably in 1861). Furthermore, all censuses of Ireland before 1901 have been lost or destroyed.

Because of World War II, there was no census in 1941. However, following the passage into law (on 5 September 1939) of the National Registration Act a population count was carried out on 29 September 1939, which was, in effect, a census.

The census is undertaken for the government by the Office for National Statistics (ONS) for policy and planning purposes, and statistical information is also made available in published reports and on the ONS's website. Public access to the census returns is restricted under the terms of the 100-year rule and the most recent returns made available to researchers are those of the 1901 Census.

The 2001 census was the first year in which the government asked about religion. Perhaps encouraged by a hoax chain letter that started in New Zealand, 390,000 people entered their religion as Jedi Knight (more than either Sikhs, Buddhists or Jews), with some areas registering up to 2.6% of people as "Jedi". It was wrongly implied in emails that stating "Jedi" on the form would cause it to become an "official religion". No such thing exists in the United Kingdom. However, the director of reporting and analysis at the ONS stated that it may have helped with the collection process as it encouraged young people, who are often missed, to complete forms. (See Jedi census phenomenon.)

All of the British censuses from 1841-1901 have been transcribed and indexed and are available online; there is a joint project between the National Archives of Ireland and Library and Archives Canada to digitize the 1901 and 1911 censuses for the whole of Ireland, and it is possible this will be completed by the end of 2007.

United States
The United States Constitution mandates that the census be taken at least once every 10 years, and that the number of members of the United States House of Representatives from each state be determined accordingly. In addition, census statistics are used for apportioning Federal funding for many social and economic programs.

The first U.S. Census was conducted in 1790 by Federal marshals. Census-takers went door-to-door and recorded the number of people in each household, along with the name of the head of the household. Slaves were enumerated, but for apportionment purposes each counted as only three-fifths of a citizen. American Indians being neither taxed nor considered during apportionment were not counted in the census. The first census counted 3.9 million people, less than half the population of New York City in 2000; the 2000 census counted over 281 million people. In 1902, Congress established the Census Bureau as a permanent Federal agency.

In recent times, there were two forms of questionnaire – long and short. The Long Form and its additional questions about items such as daily commute times, housing unit factors, etc. has been replaced by the American Community Survey (ACS). Computer algorithms (based on complex sampling rules) determined which form was mailed to a given household (in practice, of those households whose locations are on the Census Master Address List), one in six receiving the long form. This was supplemented by census workers going door-to-door to talk to people who failed to return the forms. In addition to a simple count of residents, the Census Bureau collects a variety of statistics, on topics ranging from ethnicity to the presence of indoor plumbing. While some critics claim that census questions are an invasion of privacy, the data collected by every question is either required to enforce some federal law (such as the Voting Rights Act) or is required to administer some federal program. The United States Congress gives approval to every question asked on the Census.

Despite a massive effort, the Census Bureau has never been able to count every individual, leading to controversy about whether to use statistical methods to supplement the numbers for some purposes, as well as arguments over how to improve the actual head count. The Supreme Court has ruled that only an actual head count can be used to apportion Congressional seats; however, cities and minority representatives have complained that urban residents and minorities are undercounted. In several cases, the Census Bureau will recount an area with disputed figures, provided the local government pays for the time and effort. The State of Utah protested the figures of the 2000 decennial census because it stood to gain a seat in the House of Representatives, but North Carolina gained it instead. Had the Census Bureau been mandated to count the numbers of Utahns living overseas, including many Mormon missionaries, Utah might have gained the seat.

To minimize the burden on individuals and to provide improved data, the Bureau is preparing several alternative methods for gathering economic, demographic, and social information, including the American Community Survey and record linking of depersonalized administrative records with other administrative records and Census Bureau surveys.

By law (92 Stat. 915, Public Law 95-416, enacted on October 5 1978), census records are sealed for 72 years. This figure has remained unchanged since prior to the updates of the 1978 law, reflecting an era when life expectancy was under 60 years, and thus attempts to protect individual's privacy by prohibiting the release of such information during their expected lifetimes. Thus, the most recent Census released to the public was the 1930 Census, released in 2002.

Indexes to some of the U.S. Censuses have been produced over the years, making the process of searching old census records much easier. Some indexes of census records have been produced by amateur volunteer genealogists. Due to the sheer volume of information, and the manual methodologies involved, the indexing used to be limited to the head-of-household. These indexes were published in bound volumes and are often available in regional libraries along with microfilm rolls that can be researched.

While valuable, indexes produced from these censuses can be problematic to use. The original census records from this era were completed by hand by census enumerators; this leads to problems in handwriting recognition and variations in spelling of surnames within the original documents.

The 1880 to 1920 censuses have indexes of last names, produced using the Soundex system; the indexing project was performed by the Works Progress Administration. The Soundex system is tolerant of variations in spelling; names with similar sounds but different spellings have the same encoding. The chief motivation in producing the Soundex name indexes was to assist citizens in finding census records to provide evidence of age, especially for those born before the advent of governmentally-approved birth certificates. (Verification of age was needed to establish eligibility for old-age benefits such as Social Security). Partial Soundex indexes of the 1930 census are available; resources from the Works Progress Administration were diverted towards support of World War II efforts before the project was completed.

With the advent of computers, and more recently, the Internet, expanded indexes including all family members are beginning to appear on genealogy websites. These are accompanied with hypertext links that take the researcher directly to an image of the original census page, without having to travel to a regional library and scroll through endless rolls of microfilm. (see http://www.familysearch.org or http://www.ancestry.com or http://www.census-online.com/links/ for examples)

Genealogists view censuses as secondary sources of information; primary sources of information such as birth certificates and even obituaries are viewed as more reliable. Still, census information often provides useful information for genealogists and clues on where to proceed to find further primary source documents.

Researchers must use care when working with census records. Census taker handwriting varies from excellent to illegible. Information may also be inaccurate due to spelling variants by the recorder. Some information, especially ages, may be incorrect due to vanity or confusion on the part of the information giver. Birthplaces may not be accurate depending on which family member gave the information. With these and other cautions in mind, census records can be very informative and useful.

Local
In additional to the decennial federal census, more localized versions are often used. An example of this is Massachusetts, which takes a statewide census every fifth year. Likewise, each community in Massachusetts takes a municipal census each year. Some states conducted limited censuses for various purposes which predate the 1790 federal census schedules. Various state archives can usually direct the researcher to these sources.