A census is the procedure of systematically enumerating, and acquiring and recording
information Information can be thought of as the resolution of uncertainty; it answers the question of "What an entity is" and thus defines both its essence and the nature of its characteristics. The concept of ''information'' has different meanings in d ...

about the members of a given
population In biology, a population is a number of all the organisms of the same group or species who live in a particular geographical area and are capable of interbreeding. The area of a sexual population is the area where inter-breeding is possible bet ...

. This term is used mostly in connection with
national population and housing censuses
national population and housing censuses
; other common censuses include the
census of agriculture#REDIRECT Census of agriculture {{Redirect category shell| {{R from move ...

census of agriculture
, and other censuses such as the traditional culture, business, supplies, and traffic censuses. The
United Nations The United Nations (UN) is an intergovernmental organization that aims to maintain international peace and security, develop friendly relations among nations, achieve international cooperation, and be a centre for harmonizing the actions of ...

United Nations
defines the essential features of population and housing censuses as "individual enumeration, universality within a defined territory, simultaneity and defined periodicity", and recommends that population censuses be taken at least every ten years. United Nations recommendations also cover census topics to be collected, official definitions, classifications and other useful information to co-ordinate international practices. The
Food and Agriculture Organization of the United Nations (FAO)
Food and Agriculture Organization of the United Nations (FAO)
, in turn, defines the
census of agriculture#REDIRECT Census of agriculture {{Redirect category shell| {{R from move ...

census of agriculture
as “a statistical operation for collecting, processing and disseminating data on the structure of agriculture, covering the whole or a significant part of a country.” “In a census of agriculture, data are collected at the holding level. Text was copied from this source, which is available under
Creative Commons Attribution 3.0 IGO (CC BY 3.0 IGO)
The word is of
Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Roman Republic, it became the dominant language ...

origin: during the
Roman Republic#REDIRECT Roman Republic#REDIRECT Roman Republic {{Redirect category shell|1= {{R from other capitalisation ...
{{Redirect category shell|1= {{R from other capitalisation ...

Roman Republic
, the census was a list that kept track of all adult males fit for military service. The modern census is essential to
international comparisons International comparisons, or national evaluation indicators, focuses on the quantitative, qualitative, and evaluative analysis of one country in relation to others. Often, the objective is to compare one country's performance to others in order to ...

international comparisons
of any kind of statistics, and censuses collect data on many attributes of a population, not just how many people there are. Censuses typically began as the only method of collecting national demographic data, and are now part of a larger system of different surveys. Although population estimates remain an important function of a census, including exactly the geographic distribution of the population or the agricultural population, statistics can be produced about combinations of attributes e.g. education by age and sex in different regions. Current
administrative dataAdministrative data are collected by governments or other organizations for non-statistical reasons to provide overviews on registration, transactions, and record keeping. They evaluate part of the output of administrating a program. Border records, ...

administrative data
systems allow for other approaches to enumeration with the same level of detail but raise concerns about privacy and the possibility of biasing estimates. A census can be contrasted with
sampling Sampling may refer to: *Sampling (signal processing), converting a continuous signal into a discrete signal *Sampling (graphics), converting continuous colors into discrete color components *Sampling (music), the reuse of a sound recording in anoth ...

in which information is obtained only from a subset of a population; typically main population estimates are updated by such
intercensal estimate In demographics, an intercensal estimate is an estimate of population between official census dates with both of the census counts being known. Some nations produce regular intercensal estimates while others do not. Intercensal estimates can be le ...

intercensal estimate
s. Modern census data are commonly used for research, business
marketing Marketing refers to activities a company undertakes to promote the buying or selling of a product, service, or good. It is one of the primary components of business management and commerce. Marketers can direct their product to other businesse ...

, and planning, and as a baseline for designing sample surveys by providing a sampling frame such as an address register. Census counts are necessary to adjust samples to be representative of a population by weighting them as is common in
opinion poll An opinion poll, often simply referred to as a poll or a survey, is a human research survey of public opinion from a particular sample. Opinion polls are usually designed to represent the opinions of a population by conducting a series of question ...

opinion poll
ing. Similarly,
requires knowledge of the relative sizes of different population strata, which can be derived from census enumerations. In some countries, the census provides the official counts used to apportion the number of elected representatives to regions (sometimes controversially – e.g., ''
Utah v. Evans
Utah v. Evans
''). In many cases, a carefully chosen random sample can provide more accurate information than attempts to get a population census.


A census is often construed as the opposite of a sample as its intent is to count everyone in a population rather than a fraction. However, population censuses do rely on a
sampling frameIn statistics, a sampling frame is the source material or device from which a sample is drawn. It is a list of all those within a population who can be sampled, and may include individuals, households or institutions. Importance of the sampling fram ...
to count the population. This is the only way to be sure that everyone has been included as otherwise those not responding would not be followed up on and individuals could be missed. The fundamental premise of a census is that the population is not known and a new estimate is to be made by the analysis of primary data. The use of a sampling frame is counterintuitive as it suggests that the population size is already known. However, a census is also used to collect attribute data on the individuals in the nation, not only to assess population size. This process of sampling marks the difference between a historical census, which was a house to house process or the product of an imperial decree, and the modern statistical project. The sampling frame used by census is almost always an address register. Thus it is not known if there is anyone resident or how many people there are in each household. Depending on the mode of enumeration, a form is sent to the householder, an enumerator calls, or administrative records for the dwelling are accessed. As a preliminary to the dispatch of forms, census workers will check any address problems on the ground. While it may seem straightforward to use the postal service file for this purpose, this can be out of date and some dwellings may contain a number of independent households. A particular problem is what are termed 'communal establishments' which category includes student residences, religious orders, homes for the elderly, people in prisons etc. As these are not easily enumerated by a single householder, they are often treated differently and visited by special teams of census workers to ensure they are classified appropriately.

Residence definitions

Individuals are normally counted within households, and information is typically collected about the household structure and the housing. For this reason international documents refer to censuses of population and housing. Normally the census response is made by a household, indicating details of individuals resident there. An important aspect of census enumerations is determining which individuals can be counted and which cannot be counted. Broadly, three definitions can be used: ''de facto'' residence; ''de jure'' residence; and permanent residence. This is important in considering individuals who have multiple or temporary addresses. Every person should be identified uniquely as resident in one place; but the place where they happen to be on
Census Day A census is the procedure of systematically enumerating, and acquiring and recording information about the members of a given population. This term is used mostly in connection with national population and housing censuses; other common censuses in ...
, their ''de facto'' residence, may not be the best place to count them. Where an individual uses services may be more useful, and this is at their usual residence. An individual may be recorded at a "permanent" address, which might be a family home for students or long term migrants. A precise definition of residence is needed, to decide whether visitors to a country should be included in the population count. This is becoming more important as students travel abroad for education for a period of several years. Other groups causing problems of enumeration are new-born babies, refugees, people away on holiday, people moving home around census day, and people without a fixed address. People with second homes because they are working in another part of the country or have a holiday cottage are difficult to fix at a particular address; this sometimes causes double counting or houses being mistakenly identified as vacant. Another problem is where people use a different address at different times e.g. students living at their place of education in term time but returning to a family home during vacations, or children whose parents have separated who effectively have two family homes. Census enumeration has always been based on finding people where they live, as there is no systematic alternative: any list used to find people is likely to be derived from census activities in the first place. Recent UN guidelines provide recommendations on enumerating such complex households. In the census of agriculture, data is collected at the agricultural holding unit. An agricultural holding is an economic unit of agricultural production under single management comprising all livestock kept and all land used wholly or partly for agricultural production purposes, without regard to title, legal form, or size. Single management may be exercised by an individual or household, jointly by two or more individuals or households, by a clan or tribe, or by a juridical person such as a corporation, cooperative or government agency. The holding's land may consist of one or more parcels, located in one or more separate areas or in one or more territorial or administrative divisions, providing the parcels share the same production means, such as labour, farm buildings, machinery or draught animals.

Enumeration strategies

Historical censuses used crude enumeration assuming absolute accuracy. Modern approaches take into account the problems of overcount and undercount, and the coherence of census enumerations with other official sources of data. This reflects a realist approach to measurement, acknowledging that under any definition of residence there is a true value of the population but this can never be measured with complete accuracy. An important aspect of the census process is to evaluate the quality of the data. Many countries use a post-enumeration survey to adjust the raw census counts. This works in a similar manner to
capture-recapture Mark and recapture is a method commonly used in ecology to estimate an animal population's size where it is impractical to count every individual. A portion of the population is captured, marked, and released. Later, another portion will be capt ...
estimation for animal populations. Among census experts this method is called dual system enumeration (DSE). A sample of households are visited by interviewers who record the details of the household as at census day. These data are then matched to census records, and the number of people missed can be estimated by considering the numbers of people who are included in one count but not the other. This allows adjustments to the count for non-response, varying between different
demographic Demography (from prefix ''demo-'' from Ancient Greek δῆμος (''dēmos'') meaning 'the people', and ''-graphy'' from γράφω (''graphō'') meaning 'writing, description or measurement') is the statistical study of populations, especiall ...
groups. An explanation using a fishing analogy can be found in "Trout, Catfish and Roach..." which won an award from the
Royal Statistical Society The Royal Statistical Society (RSS) is an established statistical society. It has three main roles: a British learned society for statistics, a professional body for statisticians and a charity which promotes statistics for the public good. Hi ...
for excellence in
official statistics Official statistics are statistics published by government agencies or other public bodies such as international organizations as a public good. They provide quantitative or qualitative information on all major areas of citizens' lives, such as econ ...
in 2011. Triple system enumeration has been proposed as an improvement as it would allow evaluation of the statistical dependence of pairs of sources. However, as the matching process is the most difficult aspect of census estimation this has never been implemented for a national enumeration. It would also be difficult to identify three different sources that were sufficiently different to make the triple system effort worthwhile. The DSE approach has another weakness in that it assumes there is no person counted twice (over count). In ''de facto'' residence definitions this would not be a problem but in ''de jure'' definitions individuals risk being recorded on more than one form leading to double counting. A particular problem here is students who often have a term time and family address. Several countries have used a system which is known as short form/long form. This is a
sampling Sampling may refer to: *Sampling (signal processing), converting a continuous signal into a discrete signal *Sampling (graphics), converting continuous colors into discrete color components *Sampling (music), the reuse of a sound recording in anoth ...
strategy which randomly chooses a proportion of people to send a more detailed questionnaire to (the long form). Everyone receives the short form questions. This means more data are collected, but without imposing a burden on the whole population. This also reduces the burden on the statistical office. Indeed, in the UK until 2001 all residents were required to fill in the whole form but only a 10% sample were coded and analysed in detail. New technology means that all data are now scanned and processed. Recently there has been controversy in Canada about the cessation of the mandatory long form census; the head of
Statistics Canada Statistics Canada (StatCan; french: Statistique Canada), formed in 1971, is the agency of the Government of Canada commissioned with producing statistics to help better understand Canada, its population, resources, economy, society, and culture. ...
Munir SheikhMunir Sheikh (born 1947) is a Canadian economist. Early career Born in Pakistan in 1947, Sheikh received a Master of Arts in economics from McMaster University in 1970, and earned his doctorate in economics from the University of Western Ontario in ...
, resigned upon the federal government's decision to do so. The use of alternative enumeration strategies is increasing but these are not as simple as many people assume, and are only used in developed countries. The Netherlands has been most advanced in adopting a census using
administrative dataAdministrative data are collected by governments or other organizations for non-statistical reasons to provide overviews on registration, transactions, and record keeping. They evaluate part of the output of administrating a program. Border records, ...

administrative data
. This allows a simulated census to be conducted by linking several different administrative databases at an agreed time. Data can be matched and an overall enumeration established allowing for discrepancies between different data sources. A validation survey is still conducted in a similar way to the post enumeration survey employed in a traditional census. Other countries which have a population register use this as a basis for all the census statistics needed by users. This is most common among Nordic countries, but requires many distinct registers to be combined, including population, housing, employment and education. These registers are then combined and brought up to the standard of a statistical register by comparing the data in different sources and ensuring the quality is sufficient for official statistics to be produced. A recent innovation is the French instigation of a rolling census programme with different regions enumerated each year, so that the whole country is completely enumerated every 5 to 10 years. In Europe, in connection with the 2010 census round, many countries adopted alternative census methodologies, often based on the combination of data from registers, surveys and other sources.


Censuses have evolved in their use of technology: censuses in 2010 used many new types of computing. In Brazil, handheld devices were used by enumerators to locate residences on the ground. In many countries, census returns could be made via the Internet as well as in paper form. DSE is facilitated by computer matching techniques which can be automated, such as
propensity score matching In the statistical analysis of observational data, propensity score matching (PSM) is a statistical matching technique that attempts to estimate the effect of a treatment, policy, or other intervention by accounting for the covariates that predict r ...
. In the UK, all census formats are scanned and stored electronically before being destroyed, replacing the need for physical archives. The record linking to perform an administrative census would not be possible without large databases being stored on computer systems. There are sometimes problems in introducing new technology. The US census had been intended to use handheld computers, but cost escalated and this was abandoned, with the contract being sold to Brazil. Online response has some advantages, but one of the functions of the census is to make sure everyone is counted accurately. A system which allowed people to enter their address without verification would be open to abuse. Therefore, households have to be verified on the ground, typically by an enumerator visit or post out. Paper forms are still necessary for those without access to the internet. It is also possible that the hidden nature of an administrative census means that users are not engaged with the importance of contributing their data to official statistics. Alternatively, population estimations may be carried out remotely with
GIS A geographic information system (GIS) is a conceptualized framework that provides the ability to capture and analyze spatial and geographic data. GIS applications (or GIS apps) are computer-based tools that allow the user to create interactive qu ...
remote sensing image of Death Valley colored using polarimetry. Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus is in contrast to on-site observation. The term is applied e ...


According to UNFPA, "The information generated by a population and housing census – numbers of people, their distribution, their living conditions and other key data – is critical for development." This is because this type of data is essential for policymakers so that they know where to invest. Unfortunately, many countries have outdated or inaccurate data about their populations and thus have difficulty in addressing the needs of the population. UNFPA said:
"The unique advantage of the census is that it represents the entire statistical universe, down to the smallest geographical units, of a country or region. Planners need this information for all kinds of development work, including: assessing demographic trends; analysing socio-economic conditions; designing evidence-based poverty-reduction strategies; monitoring and evaluating the effectiveness of policies; and tracking progress toward national and internationally agreed development goals."
In addition to making policymakers aware of population issues, the census is also an important tool for identifying forms of social, demographic or economic exclusions, such as inequalities relating to race, ethics, and religion as well as disadvantaged groups such as those with disabilities and the poor. An accurate census can empower local communities by providing them with the necessary information to participate in local decision-making and ensuring they are represented. The importance of the census of agriculture for development is that it gives a snapshot of the structure of the agricultural sector in a country and, when compared with previous censuses, provides an opportunity to identify trends and structural transformations of the sector, and points towards areas for policy intervention. Census data are used as a benchmark for current statistics and their value is increased when they are employed together with other data sources.

Uses of census data

Early censuses in the 19th century collected paper documents which had to be collated by hand, so the statistical information obtained was quite basic. The government owned the data could publish statistics on the state of the nation. The results were used to measure changes in the population and apportion representation. Population estimates could be compared to those of other countries. By the beginning of the 20th century, censuses were recording households and some indications of their employment. In some countries, census archives are released for public examination after many decades, allowing genealogists to track the ancestry of interested people. Archives provide a substantial historical record which may challenge established views. Information such as job titles and arrangements for the destitute and sick may also shed light on the historical structure of society. Political considerations influence the census in many countries. In Canada in 2010 for example, the government under the leadership of Stephen Harper abolished the mandatory long-form census. This abolition was a response to protests from some Canadians who resented the personal questions. The long-form census was reinstated by the Justin Trudeau government in 2016.

Census data and research

As governments assumed responsibility for schooling and welfare, large government
research Research is "creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization, and analysis of information to increase understanding of a topic or issue. A research project may be an expa ...
departments made extensive use of census data. Population projections could be made, to help plan for provision in local government and regions. Central government could also use census data to allocate funding. Even in the mid 20th century, census data was only directly accessible to large government departments. However, computers meant that tabulations could be used directly by university
research Research is "creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization, and analysis of information to increase understanding of a topic or issue. A research project may be an expa ...
ers, large businesses and local government offices. They could use the detail of the data to answer new questions and add to local and specialist knowledge. Nowadays, census data are published in a wide variety of formats to be accessible to business, all levels of government, media, students and teachers, charities, and any citizen who is interested; researchers in particular have an interest in the role of Census Field Officers (CFO) and their assistants. Data can be represented visually or analysed in complex statistical models, to show the difference between certain areas, or to understand the association between different personal characteristics. Census data offer a unique insight into small areas and small demographic groups which sample data would be unable to capture with precision. In the census of agriculture, users need census data to: # support and contribute to evidence-based agricultural planning and policy-making. The census information is essential, for example, to monitor the performance of a policy or programme designed for crop diversification or to address food security issues; # provide data to facilitate research, investment and business decisions both in the public and private sector; # contribute to monitoring environmental changes and evaluating the impact of agricultural practices on the environment such as tillage practices, crop rotation or sources of greenhouse gas (GHG) emissions; # provide relevant data on work inputs and main work activities, as well as on the labour force in the agriculture sector; # provide an important information base for monitoring some key indicators of the Sustainable Development Goals (SDGs), in particular those goals related to food security in agricultural holdings, the role of women in agricultural activities and rural poverty; # provide baseline data both at the national and small administrative and geographical levels for formulating, monitoring and evaluating programmes and projects interventions; # provide essential information on subsistence agriculture and for the estimation of the non-observed economy, which plays an important role in the compilation of the national accounts and the economic accounts for agriculture.

Privacy and data stewardship

Although the census provides useful statistical information about a population, the availability of this information could sometimes lead to abuses, political or otherwise, by the linking of individuals' identities to anonymous census data. This is particularly important when individuals' census responses are made available in microdata form, but even aggregate-level data can result in privacy breaches when dealing with small areas and/or rare subpopulations. For instance, when reporting data from a large city, it might be appropriate to give the average income for black males aged between 50 and 60. However, doing this for a town that only has two black males in this age group would be a breach of privacy because either of those persons, knowing his own income and the reported average, could determine the other man's income. Typically, census data are processed to obscure such individual information. Some agencies do this by intentionally introducing small statistical errors to prevent the identification of individuals in marginal populations; others swap variables for similar respondents. Whatever is done to reduce the privacy risk, new improved electronic analysis of data can threaten to reveal sensitive individual information. This is known as
statistical disclosure controlStatistical disclosure control (SDC), also known as statistical disclosure limitation (SDL) or disclosure avoidance, is a technique used in data-driven research to ensure no person or organization is identifiable from the results of an analysis of su ...
. Another possibility is to present survey results by means of statistical models in the form of a multivariate distribution mixture. The statistical information in the form of conditional distributions (
histogram A histogram is an approximate representation of the distribution of numerical data. It was first introduced by Karl Pearson. To construct a histogram, the first step is to "bin" (or "bucket") the range of values—that is, divide the entire range ...
s) can be derived interactively from the estimated
mixture model In statistics, a mixture model is a probabilistic model for representing the presence of subpopulations within an overall population, without requiring that an observed data set should identify the sub-population to which an individual observation ...
without any further access to the original database. As the final product does not contain any protected microdata, the model-based interactive software can be distributed without any confidentiality concerns. Another method is simply to release no data at all, except very large scale data directly to the central government. Different release strategies between government have led to an international project (
IPUMS Integrated Public Use Microdata Series (IPUMS) is the world's largest individual-level population database. IPUMS consists of microdata samples from United States ''(IPUMS-USA)'' and international ''(IPUMS-International)'' census records, as well a ...
) to co-ordinate access to microdata and corresponding metadata. Such projects such as SDMX also promote standardising metadata, so that best use can be made of the minimal data available.

History of censuses


Censuses in Egypt first appeared in the late Middle Kingdom and developed in the
New Kingdom New is an adjective referring to something recently made, discovered, or created. New or NEW may refer to: Music * New, singer of K-pop group The Boyz Albums and EPs * ''New'' (album), by Paul McCartney, 2013 * ''New'' (EP), by Regurgitator, 19 ...
Pharaoh Amasis, according to
Herodotus Herodotus (; grc|Ἡρόδοτος, ''Hēródotos'', ; BC) was an ancient Greek historian who was born in Halicarnassus in the Persian Empire (modern-day Bodrum, Turkey). He is known for having written the book ''The Histories'' ( grc|Ἱσ ...
, required every Egyptian to declare annually to the
nomarch A nomarch ( grc|νομάρχης, egy|ḥrj tp ꜥꜣ Great Chief) was a provincial governor in ancient Egypt; the country was divided into 42 provinces, called nomes (singular , plural ). A nomarch was the government official responsible for ...
, "whence he gained his living". Under the
Ptolemies#REDIRECT Ptolemaic dynasty ...
and the
Romans Roman or Romans usually refers to: *Rome, the capital city of Italy *Ancient Rome, Roman civilization from 8th century BC to 5th century AD *Roman people, the people of ancient Rome *''Epistle to the Romans'', shortened to ''Romans'', a letter in ...
several censuses were conducted in Egypt by government officials

Ancient Greece

There are several accounts of ancient Greek city states carrying out censuses.


Censuses are mentioned in the
Bible The Bible (from Koine Greek τὰ βιβλία, ''tà biblía'', "the books") is a collection of religious texts or scriptures sacred to Christians, Jews, Samaritans, Rastafari and others. It appears in the form of an anthology, a compilati ...
. God commands a per capita tax to be paid with the census for the upkeep of the
Tabernacle , Israel According to the Hebrew Bible, the Tabernacle ( he|מִשְׁכַּן, ''mishkān'', meaning "residence" or "dwelling place"), also known as the Tent of the Congregation (אֹ֣הֶל מוֹעֵד֩ ''’ōhel mō‘êḏ'', also Tent of ...

. The
Book of Numbers The Book of Numbers (from Greek Ἀριθμοί, ''Arithmoi''; he|בְּמִדְבַּר, Bəmiḏbar, "In the desert f) is the fourth book of the Hebrew Bible, and the fourth of five books of the Jewish Torah. The book has a long and complex his ...
is named after the counting of the Israelite population according to the house of the Fathers after the exodus from Egypt. A second census was taken while the Israelites were camped in the plains of
Moab Moab ''Mōáb''; Assyrian: 𒈬𒀪𒁀𒀀𒀀 ''Mu'aba'', 𒈠𒀪𒁀𒀀𒀀 ''Ma'ba'', 𒈠𒀪𒀊 ''Ma'ab''; Egyptian: 𓈗𓇋𓃀𓅱𓈉 ''Mū'ībū''|name=|group= () is the name of an ancient kingdom whose territory is today located ...
. King
David David (traditional spelling), , ''Dāwūd''; grc-koi|Δαυίδ|Dauíd; la|Davidus, David; gez |ዳዊት, ''Dawit''; xcl|Դաւիթ, ''Dawitʿ''; cu|Давíдъ, ''Davidŭ''; possibly meaning "beloved one". is described in the Hebrew Bib ...
performed a census that produced disastrous results. His son, King
Solomon Solomon (; he|שְׁלֹמֹה, ''Shlomoh),'' ''Šlēmūn''; Arabic: سُلَيْمَان ', also colloquially: ' or '; el|Σολομών ''Solomōn''; Latin: Salomon) also called Jedidiah (Hebrew ''Yedidyah''), was, according to the Hebrew ...
, had all of the foreigners in Israel counted. When the Romans took over Judea in AD6, the legate
Publius Sulpicius Quirinius Publius Sulpicius Quirinius (c. 51 BC – AD 21), also translated as Cyrenius, was a Roman aristocrat. After the banishment of the ethnarch Herod Archelaus from the tetrarchy of Judea in AD 6, Quirinius was appointed legate governor of Syria, ...
organised a
census A census is the procedure of systematically enumerating, and acquiring and recording information about the members of a given population. This term is used mostly in connection with national population and housing censuses; other common censuses in ...
for tax purposes. The
Gospel of Luke The Gospel according to Luke ( el|Εὐαγγέλιον κατὰ Λουκᾶν |translit=Euangélion katà Loukân), also called the Gospel of Luke, or simply Luke, tells of the origins, birth, ministry, death, resurrection, and ascension of Jesu ...
links the birth of Jesus to this event.


One of the world's earliest preserved censuses was held in China in AD2 during the
Han Dynasty The Han dynasty () was the second imperial dynasty of China (202 BC – 220 AD), established by the rebel leader Liu Bang and ruled by the House of Liu. Preceded by the short-lived Qin dynasty (221–206 BC) and a warring interregnum known a ...
, and is still considered by scholars to be quite accurate.Twitchett, D., Loewe, M., and Fairbank, J.K. ''Cambridge History of China: The Ch'in and Han Empires 221 B.C.–A.D. 220''. Cambridge University Press (1986), p. 240. The population was registered as having 57,671,400 individuals in 12,366,470 households. Another census was held in AD144.


The oldest recorded census in India is thought to have occurred around 330BC during the reign of Emperor
Chandragupta Maurya Chandragupta Maurya (reign: 321–297 BCE) was the founder of the Maurya Empire in ancient India. He was taught and counselled by the philosopher Chanakya, who had great influence in the formation of his empire. Together, Chandragupta and Chan ...
under the leadership of
Kautilya Chanakya (IAST: ', ) was an ancient Indian teacher, philosopher, economist, jurist and royal advisor. He is traditionally identified as Kauṭilya or Vishnugupta, who authored the ancient Indian political treatise, the ''Arthashastra'', a text ...
or Chanakya and
Ashoka Ashoka (; Brāhmi: 𑀅𑀲𑁄𑀓, ''Asoka'', IAST: Aśoka), also known as Ashoka the Great, was an Indian emperor of the Maurya Dynasty, who ruled almost all of the Indian subcontinent from to 232 BCE. A grandson of the dynasty's founder C ...



The English term is taken directly from the
Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Roman Republic, it became the dominant language ...
''census'', from ' ("to estimate"). The census played a crucial role in the administration of the Roman government, as it was used to determine the class a citizen belonged to for both military and tax purposes. Beginning in the middle republic, it was usually carried out every five years. It provided a register of citizens and their property from which their duties and privileges could be listed. It is said to have been instituted by the Roman king
Servius Tullius Servius Tullius was the legendary sixth king of Rome, and the second of its Etruscan dynasty. He reigned from 578 to 535 BC. Roman and Greek sources describe his servile origins and later marriage to a daughter of Lucius Tarquinius Priscus, Rome' ...
in the at which time the number of arms-bearing citizens was supposedly counted at around 80,000. The 6AD "
census of Quirinius The Census of Quirinius was a census of Judea taken by Publius Sulpicius Quirinius, Roman governor of Syria, upon the imposition of direct Roman rule in 6 CE. The Gospel of Luke uses it as the narrative means to establish the birth of Jesus in Beth ...
" undertaken following the imposition of direct Roman rule in
Judea Judea or Judaea, and the modern version of Judah (; from he|יהודה, Standard ''Yəhūda'', Tiberian ''Yehūḏā''; el|Ἰουδαία, ; la|Iūdaea) is the ancient, historic, Biblical Hebrew, contemporaneous Latin, and the modern-day n ...
was partially responsible for the development of the
Zealot The Zealots were a political movement in 1st-century Second Temple Judaism which sought to incite the people of Judea Province to rebel against the Roman Empire and expel it from the Holy Land by force of arms, most notably during the First Jewis ...
movement and several failed rebellions against Rome that ended in the
Diaspora A diaspora () is a scattered population whose origin lies in a separate geographic locale. Historically, the word diaspora was used to refer to the mass dispersion of a population from its indigenous territories, specifically the dispersion of ...
. The 15-year
indiction An indiction ( la|indictio, impost) was a periodic reassessment of taxation in the Roman Empire which took place every fifteen years. In Late Antiquity, this 15-year cycle began to be used to date documents and it continued to be used for this purp ...
cycle established by
Diocletian Diocletian (; la|Gaius Aurelius Valerius Diocletianus; Greek: Διοκλητιανός; born Diocles; 22 December c. 244 – 3 December 311) was a Roman emperor from 284 to 305. Born to a family of low status in Dalmatia, Diocletian rose through ...
in AD297 was based on quindecennial censuses and formed the basis for dating in late antiquity and under the
Byzantine Empire The Byzantine Empire, also referred to as the Eastern Roman Empire, or Byzantium, was the continuation of the Roman Empire in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinople. It surviv ...

Rashidun and Umayyad Caliphates

In the
Middle Ages In the history of Europe, the Middle Ages or medieval period lasted from the 5th to the late 15th century. It began with the fall of the Western Roman Empire and transitioned into the Renaissance and the Age of Discovery. The Middle Ages i ...
, the
Caliphate A caliphate ( ar|خِلَافَة, ) is an Islamic state under the leadership of an Islamic steward with the title of caliph (; ar|خَلِيفَة ', ), a person considered a politico-religious successor to the Islamic prophet Muhammad and ...
began conducting regular censuses soon after its formation, beginning with the one ordered by the second
Rashidun | image = تخطيط كلمة الخلفاء الراشدون.png | caption = Calligraphic representation of Rashidun Caliphs | birth_place = Mecca, Hejaz, Arabia present-day Saudi Arabia | known_for = Companions of the Pr ...
caliph A caliphate ( ar|خِلَافَة, ) is an Islamic state under the leadership of an Islamic steward with the title of caliph (; ar|خَلِيفَة ', ), a person considered a politico-religious successor to the Islamic prophet Muhammad and ...
Umar | house = Quraysh (Banu Adi) | house-type = Tribe | father = Khattab ibn Nufayl | mother = Hantamah binti Hisham Omar (English: , also spelled Umar ; ar|عمر بن الخطاب , , "Umar, Son of Al-Khattab"; c. 584 CE3 November ...


Medieval Europe

Domesday Book Domesday Book ( or , Middle English for "Doomsday Book"; Latin: ''Liber de Wintonia'' "Book of Winchester") is a manuscript record of the "Great Survey" of much of England and parts of Wales completed in 1086 by order of King William the Conque ...
was undertaken in AD1086 by
William I of England William I (c. 1028Bates ''William the Conqueror'' p. 33 – 9 September 1087), usually known as William the Conqueror and sometimes William the Bastard, was the first Norman monarch of England, reigning from 1066 until his death in 108 ...
so that he could properly tax the land he had recently conquered. In 1183, a census was taken of the
crusade The Crusades were a series of religious wars initiated, supported, and sometimes directed by the Latin Church in the medieval period. The term refers especially to the Eastern Mediterranean campaigns in the period between 1095 and 1271 that h ...
Kingdom of Jerusalem The Kingdom of Jerusalem ( la|Regnum Hierosolymitanum; fro|Roiaume de Jherusalem), also known as the Latin Kingdom of Jerusalem, was a Crusader state established in the Southern Levant by Godfrey of Bouillon in 1099 after the First Crusade. The ...
, to ascertain the number of men and amount of money that could possibly be raised against an invasion by
Saladin Al-Nasir Salah al-Din Yusuf ibn Ayyub ( ar|الناصر صلاح الدين يوسف بن أيوب|An-Nāṣir Ṣalāḥ ad-Dīn Yūsuf ibn Ayyūb; ku|سەلاحەدینی ئەییووبی|Selahedînê Eyûbî; 11374 March 1193), better known s ...
, sultan of
Egypt Egypt ( ; ar|مِصر ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia by a land bridge formed by the Sinai Peninsula. Egypt is a Mediterranean count ...
Syria Syria ( ar|سُورِيَا|''Sūriyā''), officially the Syrian Arab Republic ( ar|ٱلْجُمْهُورِيَّةُ ٱلْعَرَبِيَّةُ ٱلسُّورِيَّةُ|al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a country in West ...
. 1328 : First national census of France (''L'État des paroisses et des feux'') mostly for fiscal purposes. It estimated the French population at 16 to 17 millions.

Inca Empire

In the 15th century, the
Inca Empire The Inca Empire ( qu|Tawantinsuyu,  "four parts together"), also known as the Incan Empire and the Inka Empire, was the largest empire in pre-Columbian America. The administrative, political and military center of the empire was in the city ...
had a unique way to record census information. 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.

Spanish Empire

On May 25, 1577, [[Philip II of Spain|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, were distributed to local officials in the Viceroyalties of New Spain and Peru to direct the gathering of information. The questionnaire, composed 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 "", were written between 1579 and 1585 and were returned to the Cronista Mayor in Spain by the Council of the Indies.

World population estimates

The earliest estimate of the world population was made by [[Giovanni Battista Riccioli in 1661; the next by [[Johann Peter Süssmilch in 1741, revised in 1762; the third by [[Karl Friedrich Wilhelm Dieterici in 1859. In 1931, Walter Willcox published a table in his book, ''International Migrations: Volume II Interpretations'', that estimated the 1929 world population to be roughly 1.8 billion.

Impact of COVID-19 on census


[[United Nations Population Fund|UNFPA predicts that the [[COVID-19 pandemic will threaten the successful conduct of censuses of population and housing in many countries through delays, interruptions that compromise quality, or complete cancellation of census projects. Domestic and donor financing for census may be diverted to address COVID-19 leaving census without crucial funds. Several countries have already taken decisions to postpone the census, with many others yet to announce the way forward. In some countries this is already happening. The pandemic has also affected the planning and implementation of censuses of agriculture in all world's regions. The extent of the impact has varied according to the stages at which the censuses are, ranging from planning (i.e. staffing, procurement, preparation of frames, questionnaires), fieldwork (field training and enumeration) or data processing/analysis stages. The census of agriculture's reference period is the agricultural year. Thus, a delay in any census activity may be critical and can result in a full year postponement of the enumeration if the agricultural season is missed. Some publications have discussed the impact of COVID-19 on national censuses of agriculture.


UNFPA has requested a global effort to assure that even where census is delayed, census planning and preparations are not cancelled, but continue in order to assure that implementation can proceed safely when the pandemic is under control. While new census methods, including online, register-based, and hybrid approaches are being used across the world, these demand extensive planning and preconditions that cannot be created at short notice. The continuing low supply of [[personal protective equipment to protect against COVID-19 has immediate implications for conducting census in communities at risk of transmission. UNFPA Procurement Office is partnering with other agencies to explore new supply chains and resources.

Modern implementation

See also

* [[List of national and international statistical services * * * *




* Alterman, Hyman, (1969). ''Counting People: The Census in History''. Harcourt, Brace & Company. * Behrisch, Lars. (2016) "Statistics and Politics in the 18th Century." ''Historical Social Research/Historische Sozialforschung'' (2016): 238–57. * Bielenstein, Hans, (1978). "Wang Mang, the restoration of the Han dynasty, and Later Han." In ''The Cambridge History of China'', vol. 1, eds. Denis Twitchett and John K. Fairbank, pp. 223–90, Cambridge: Cambridge University Press. * Krüger, Stephen, (Fall 1991). "The Decennial Census"
19 ''Western State University Law Review'' 1
available a
Effects of UK 'Jedi' hoax on 2001 UK census from ONS


External links

Census of Ireland 1911

Online Historical Population Reports Project (OHPR)

PR as a function of census management: comparative analysis of fifteen census experiences
{{Authority control [[Category:Censuses [[Category:Population [[Category:Survey methodology [[Category:Sampling (statistics) [[Category:Latin words and phrases