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

Census data is commonly used for research, marketing, and planning. For example, population and housing data might determine where schools are constructed or where new bus routes are placed. 

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.

Historical Censuses

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. 

National Censuses 

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
The first census of the U.S. population was conducted in 1790.

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.

Going Dutch
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!

achieve
Verb

to accomplish or attain.

alpaca
Noun

domesticated mammal related to the llama, native to South America.

ancestry
Noun

family (genealogical) or historical background.

ancient Rome
Noun

civilization founded on the Mediterranean Sea, lasting from the 8th century BCE to about 476 CE.

Andes Mountains
Noun

mountain range extending along the western coast of South America.

assessor
Noun

person who evaluates the worth of property or another valuable item, usually for taxation purposes.

asset
Noun

property or another valuable item that is possessed by someone.

broadband
noun, adjective

high-speed data transmission or communication where the bandwidth is shared by more than one signal.

cattle
Noun

cows and oxen.

Noun

program of a nation, state, or other region that counts the population and usually gives its characteristics, such as age and gender.

characteristic
Noun

physical, cultural, or psychological feature of an organism, place, or object.

citizen
Noun

member of a country, state, or town who shares responsibilities for the area and benefits from being a member.

Noun

complex way of life that developed as humans began to develop urban settlements.

conduct
Verb

to transmit, transport, or carry.

Noun

political unit smaller than a state or province, but typically larger than a city, town, or other municipality.

criteria
Plural Noun

set of standards or rules.

Noun

agricultural produce.

data
Plural Noun

(singular: datum) information collected during a scientific study.

Noun

growth, or changing from one condition to another.

distinguish
Verb

to differentiate or recognize as different.

Domesday Book
Noun

(1086) census and survey of England, noting ownership of land and assets.

economic
Adjective

having to do with money.

empire
Noun

group of nations, territories or other groups of people controlled by a single, more powerful authority.

evaluate
Verb

to decide something's worth.

fertile
Adjective

able to produce crops or sustain agriculture.

government
Noun

system or order of a nation, state, or other political unit.

hut
Noun

simple, roofed structure usually made from natural materials such as wood and grasses.

implement
Verb

to carry out plans.

import
Verb

to bring in a good or service from another area for trade.

Incan Empire
Noun

(1438-1533) empire stretching along the coastal highlands and Andes mountains of South America.

independence
Noun

state or situation of being free.

indicator
Noun

sign or signal.

Adjective

characteristic to or of a specific place.

Internet
Noun

vast, worldwide system of linked computers and computer networks.

Noun

type of government with a king or queen as its leader, or the land ruled by that king or queen.

llama
Noun

large mammal native to South America.

marketing
Noun

art and science of selling a product.

mita
Noun

form of required public service and tax in the Incan Empire.

Noun

political unit made of people who share a common territory.

Noun

an area within a larger city or town where people live and interact with one another.

numeric
Adjective

having to do with numbers.

occupation
Noun

job, work, or career.

participation
Noun

taking part in an activity.

permit
Noun

official, written permission to do something. Sometimes called a license.

politics
Noun

art and science of public policy.

population
Noun

total number of people or organisms in a particular area.

property
Noun

goods or materials (including land) owned by someone.

protectorate
Noun

territory controlled by another state or nation but not a part of it.

questionnaire
Noun

short list of specific questions, whose replies can be used in research.

quipu
Noun

knotted cord used by the ancient Incan Empire to record events, census data, and accounts. Also spelled khipu.

quipucamayoc
Noun

census-takers and government workers in the Incan empire.

Noun

any area on Earth with one or more common characteristics. Regions are the basic units of geography.

remote
Adjective

distant or far away.

representative
Noun

someone or something who acts in place of a group of people.

republic
Noun

system of government where power rests in citizens who vote and representatives who stand for those citizens. The United States is a republic.

research
Noun

scientific observations and investigation into a subject, usually following the scientific method: observation, hypothesis, prediction, experimentation, analysis, and conclusion.

resource
Noun

available supply of materials, goods, or services. Resources can be natural or human.

right
Noun

specific freedom or opportunity granted to an individual or organization based on the law.

route
Noun

path or way.

scholar
Noun

educated person.

sector
Noun

section or a part of something.

sex
Noun

male or female: division into which sexually reproducing organisms are divided.

sophisticated
Adjective

knowledgeable or complex.

state
Noun

political unit in a nation, such as the United States, Mexico, or Australia.

strategic
Adjective

important part of a place or plan.

survey
Noun

a study or analysis of characteristics of an area or a population.

tax
Noun

money or goods citizens provide to government in return for public services such as military protection.

technology
Noun

the science of using tools and complex machines to make human life easier or more profitable.

unique
Adjective

one of a kind.

United Kingdom
Noun

nation made of the countries of England, Wales, Scotland, and Northern Ireland.

United Nations
Noun

international organization that works for peace, security and cooperation.

William the Conqueror
Noun

(1027-1087) king of England. Also called William I.

work force
Noun

number of people who are employed or available for employment.