A CENSUS is the procedure of systematically acquiring and recording
information about the members of a given population . The term is used
mostly in connection with national population and housing censuses ;
other common censuses include agriculture, business, and traffic
The word is of
A census can be contrasted with sampling in which information is
obtained only from a subset of a population; typically main population
estimates are updated by such intercensal estimates . Modern census
data are commonly used for research, business marketing , and
planning, and as a baseline for designing sample surveys by providing
a sampling frame such as an address register.
* 1 Sampling
* 2 Residence definitions
* 3 Enumeration strategies
* 4 Technology
* 6 Uses of census data
* 7 Privacy
* 8 Historical censuses
* 9 World population estimates * 10 Modern implementation * 11 See also * 12 Notes * 13 References * 14 External links
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 rely on a sampling frame 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. This process of sampling marks the difference between 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 While it may seem straightforward to use the postal service file for this purpose, this can be out of date and some dwellings may contain a number of independent households.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.
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
from which cannot be counted. Broadly, three definitions can be used:
de facto residence; de jure residence; and, permanent residence. This
is important to consider individuals who have multiple or temporary
addresses. Every person should be identified uniquely as resident in
one place but where they happen to be on
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
estimation for animal populations. In census circles 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 number
missed in the census or survey but counted in the other. This way
counts can be adjusted for non-response varying between different
demographic groups. An explanation using a fishing analogy can be
found in "Trout, Catfish and Roach..." which won an award from the
Royal Statistical Society for excellence in official statistics in
2011. Enumerator conducting a survey using a mobile phone based
questionnaire in rural
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 are 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 strategy which randomly chooses a proportion of people to send a more detailed questionnaire to (the long form). Everyone receives the short form questions. Thereby more data are collected but not imposing a burden on the whole population. This also reduces the burden on the statistical office. Indeed, in the UK all residents were required to fill in the whole form but only a 10% sample were coded and analysed in detail, until 2001. New technology means that all data are now scanned and processed. Recently there has been controversy in Canada about the cessation of the long form with the head, Munir Sheikh resigning.
The use of alternative enumeration strategies is increasing but
these are not so simple as many people assume and only occur in
developed countries. The
Censuses have evolved in their use of technology with the latest censuses, the 2010 round, using 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 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.
New technology is not without problems in its introduction. The US census had intended to use the handheld computers but cost escalated and this was abandoned, with the contract being sold to Brazil. Online response is a good idea but one of the functions of 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 Internet connections. 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
CENSUS AND DEVELOPMENT
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 therefore, without accurate data are unable to address the needs of their population.
UNFPA stated that,
“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 about population issues, it 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.
USES OF CENSUS DATA
In the nineteenth century, the first censuses collected paper enumerations that had to be collated by hand so the statistical uses were very basic. The government owned the data and were able to publish statistics themselves on the state of the nation. Uses were to measure changes in the population and apportion representation. Population estimates could be compared to those of other countries.
By the beginning of the twentieth 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 notions of tradition. It is also possible to understand the societal history through job titles and arrangements for the destitute and sick.
There are a lot of politics that surround 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. The decision to cut the long-form census 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 departments made extensive use of census data. Actuarial estimates could be made to project populations and plan for provision in local government and regions. It was also possible for central government to allocate funding on the basis of census data. Even into the mid twentieth century, census data was only directly accessible to large government departments. However, computers meant that tabulations could be used directly by university researchers , 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.
Now, census data are published in a wide variety of formats to be
accessible to business, all levels of governance, media, students and
teachers, charities and any citizen who is interested; researchers in
particular have an interest in the role of
Although 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. This consideration 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 measures have been taken to reduce the privacy risk in census data, new technology in the form of better electronic analysis of data poses increasing challenges to the protection of sensitive individual information. This is known as statistical disclosure control .
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 (histograms ) can be derived interactively from the estimated mixture model 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 ) to co-ordinate access to microdata and corresponding metadata. Such projects also promote standardising metadata by projects such as SDMX so that best use can be made of the minimal data available.
There are several accounts of ancient Greek city states carrying out censuses.
Censuses are mentioned in the
When the Romans took over Judea in AD 6, the legate Publius Sulpicius
Quirinius organised a census for tax purposes. The Gospel of Luke
links the birth of
One of the world's earliest preserved censuses was held in China in
AD 2 during the
The word "census" originated in ancient Rome from the
RASHIDUN AND UMAYYAD CALIPHATES
In the 15th century, the
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, 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 "relaciones geográficas," 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. League of Nations and International Statistical Institute estimates of the world population in 1929
Main article: Population and housing censuses by country Nigerian leaders cannot put a number on the amount of Nigerian women and girls that have gone missing. Nigeria has never had a credible, successful census. —Olúfémi Táíwò, professor of Africana studies at Cornell University
* Alterman, Hyman, (1969). Counting People: The
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