A census counts the population of a nation, state, or other geographic region. It records information about the population’s characteristics, such as age, sex, and occupation. It may also include data about the region’s agricultural and business sectors. National governments usually conduct censuses every five to 10 years, as recommended by the United Nations.
In some countries, census data is used to figure out the number of representatives a given community will have in government. In the United States, for example, a county with a large population will have more representatives in state government than a less-populated one.
Many early civilizations used census data to determine how their governments would operate. Leaders of ancient Rome depended on censuses to govern their republic and, later, empire. Each male citizen had to appear before the census-takers and account for himself, his family, and his property. The Roman government determined the social position of each citizen by the amount of property he owned. Men with highly prized property enjoyed greater rights and freedoms.
The most well-known historic census appears in the Domesday Book, a survey of England completed in 1086. Scholars say this survey determined the property rights of King William I (William the Conqueror). Assessors recorded how much property and assets—such as cattle and crops—citizens owned, and then taxed them accordingly. William I had conquered England only 20 years earlier. The Domesday Book helped him evaluate what wealth his new kingdom held, and where strategic assets were located.
The Incan Empire conducted perhaps the most unique census of the 15th century. The Incas, whose empire stretched across the Andes mountains, did not have a written language. They recorded information on quipus. A quipuis is a rope made from llama or alpaca hair, or cotton cords. A series of knots on the quipu defined certain numeric and non-numeric values. The Quipucamayocs, or quipu authorities, used these cords to keep track of mita, a form of taxes, and also to run a census of the local population. Quipus recorded the ages, occupations, and wealth of Incan citizens. Some remote Peruvian villages, although very few, still use the quipu system for official local government records.
Today, most national governments conduct censuses for planning purposes. New census-taking technologies and practices have helped governments achieve better results. For example, in 2006, Australia allowed citizens to complete parts of their census online in order to increase participation. In 2011, the country implemented the new Australian Statistical Geography Standard, which allowed census-takers to record more detailed data about populations in limited boundaries, such as postal areas.
Nations organize their census information differently. Criteria are based on factors such as land size, government structure, and economic resources. With about 8.5 million square kilometers (3.3 million square miles) of territory to cover, Brazil records one of the most detailed collections of census data in the world. This collection includes ranked sets of data about the nation of Brazil, major regions, states, municipalities, districts, subdistricts, and neighborhoods.
In 2010, Brazil implemented a number of strategies that aim to increase citizen participation in the census, especially in areas of the country that are hard to reach. Census-takers used handheld computers. These sophisticated computers record and store information on a country-wide broadband internet service. Finally, the handheld computers are able to translate the questionnaire into different indigenous languages, improving the participation of the many indigenous communities in Brazil.
A country’s historical census data shows how the population has changed and gives clues about its history and politics. The censuses of 1911, 1921, and 1931 counted the population by “huts” and not individuals. “Huts” included both individuals and families.
The 1948 and 1959 Ugandan censuses counted individuals, but divided the population between Africans and non-Africans. Uganda was a protectorate of the United Kingdom. Often, ancestry was an indicator of social status. It was important to the government that the census distinguish between those of African, Asian, and European ancestry. After Uganda declared independence in 1962, censuses were taken jointly for all races.
Preparing for and conducting a census requires a lot of time, resources, and labor. The result is large sets of data that tell us about who and what make up our communities, regions, and countries. Ultimately, this data helps political leaders and citizens improve the places in which we live, work, and play.
Census of Marine Life
In 2010, scientists finished the first-ever census of life in the world's oceans. The 10-year project, partly financed by the National Geographic Society, found there are nearly 250,000 known species in the sea. It also found more than 6,000 potentially new species.
The Netherlands has not conducted an official census since 1971 out of concern for individual privacy.
Using the Force
More than 400,000 people wrote "Jedi" as their religion on the 2001 census forms in Australia, Canada, England, New Zealand, Scotland, and Wales. More people considered themselves Jedi, an order of people from the Star Wars movies, than Jewish.
Counting Up China
How does the most populated country in the world count its population? China, with a population of about 1.3 billion, needed 6 million census-takers in 2010 to count every man, woman, and child in the country!
to accomplish or attain.
domesticated mammal related to the llama, native to South America.
family (genealogical) or historical background.
civilization founded on the Mediterranean Sea, lasting from the 8th century BCE to about 476 CE.
mountain range extending along the western coast of South America.
person who evaluates the worth of property or another valuable item, usually for taxation purposes.
property or another valuable item that is possessed by someone.
high-speed data transmission or communication where the bandwidth is shared by more than one signal.
cows and oxen.
program of a nation, state, or other region that counts the population and usually gives its characteristics, such as age and gender.
physical, cultural, or psychological feature of an organism, place, or object.
member of a country, state, or town who shares responsibilities for the area and benefits from being a member.
complex way of life that developed as humans began to develop urban settlements.
to transmit, transport, or carry.
political unit smaller than a state or province, but typically larger than a city, town, or other municipality.
set of standards or rules.
(singular: datum) information collected during a scientific study.
growth, or changing from one condition to another.
to differentiate or recognize as different.
(1086) census and survey of England, noting ownership of land and assets.
having to do with money.
group of nations, territories or other groups of people controlled by a single, more powerful authority.
to decide something's worth.
able to produce crops or sustain agriculture.
system or order of a nation, state, or other political unit.
simple, roofed structure usually made from natural materials such as wood and grasses.
to carry out plans.
to bring in a good or service from another area for trade.
(1438-1533) empire stretching along the coastal highlands and Andes mountains of South America.
state or situation of being free.
sign or signal.
characteristic to or of a specific place.
vast, worldwide system of linked computers and computer networks.
type of government with a king or queen as its leader, or the land ruled by that king or queen.
large mammal native to South America.
art and science of selling a product.
form of required public service and tax in the Incan Empire.
political unit made of people who share a common territory.
an area within a larger city or town where people live and interact with one another.
having to do with numbers.
job, work, or career.
taking part in an activity.
official, written permission to do something. Sometimes called a license.
art and science of public policy.
total number of people or organisms in a particular area.
goods or materials (including land) owned by someone.
territory controlled by another state or nation but not a part of it.
short list of specific questions, whose replies can be used in research.
knotted cord used by the ancient Incan Empire to record events, census data, and accounts. Also spelled khipu.
census-takers and government workers in the Incan empire.
any area on Earth with one or more common characteristics. Regions are the basic units of geography.
distant or far away.
someone or something who acts in place of a group of people.
system of government where power rests in citizens who vote and representatives who stand for those citizens. The United States is a republic.
scientific observations and investigation into a subject, usually following the scientific method: observation, hypothesis, prediction, experimentation, analysis, and conclusion.
available supply of materials, goods, or services. Resources can be natural or human.
specific freedom or opportunity granted to an individual or organization based on the law.
path or way.
section or a part of something.
male or female: division into which sexually reproducing organisms are divided.
knowledgeable or complex.
political unit in a nation, such as the United States, Mexico, or Australia.
important part of a place or plan.
a study or analysis of characteristics of an area or a population.
money or goods citizens provide to government in return for public services such as military protection.
the science of using tools and complex machines to make human life easier or more profitable.
one of a kind.
nation made of the countries of England, Wales, Scotland, and Northern Ireland.
international organization that works for peace, security and cooperation.
William the Conqueror
(1027-1087) king of England. Also called William I.
number of people who are employed or available for employment.