Census is a survey conducted by a national government to gather information about the society that it governs. Censuses examine such aspects of a nation as population, housing, agriculture, and manufacturing. A population census determines the size of a population and such information as the age, employment, income, race, and sex of people. Other censuses gather such data as the quality of housing or transportation, the level of agricultural or industrial production, or the form of organization of local governments. Most of the world’s nations conduct a population census. Governmental administration of a census helps ensure that the census is accurate and serves the entire society.
In conducting a census, a government first selects topics to be included and prepares questions that are easy to understand and can be answered accurately. Questionnaires are designed to avoid anything that might bias (slant) responses. Next, the government publicizes the census to encourage public cooperation. The government prepares maps and lists of households. Regional and local offices are established, and temporary workers are hired and trained. Then, census takers contact one or more adults in each household by mail, personal visit, or telephone and ask them to provide information about everyone who lives there.
Upon receiving the information, census takers process, tabulate, and organize the results. National, state or provincial, and local governments analyze the data to determine the extent of economic and social problems. The results also help identify resources available to solve such problems. Most national governments make census information available to the public.
The United Nations (UN) encourages all nations to conduct complete periodic censuses. The UN publishes manuals of recommended census procedures and content questions. It also helps arrange technical support. It works to establish standards for censuses to collect accurate world statistics. The UN publishes summary data for most countries of the world in its annual Demographic Yearbook.
Censuses throughout history
Early population counts
generally were not concerned with determining the total size of the population or including detailed information about people. Their main goal was to discover who was available for military duty and who held taxable property. These counts usually did not give an accurate number or picture of the population. They often left out large segments of society, such as women and children, men attempting to avoid military service or taxation, and native inhabitants of an area.
The earliest known population counts were made thousands of years ago by the ancient Chinese, Egyptians, and Mesopotamians. Around 2500 B.C., the Mesopotamians recorded on clay tablets information about the taxpaying part of the population. These tablets included such data as the number of farm animals, farm products, and households for districts within the kingdom. Tax returns from around 2300 B.C. for parts of ancient China indicate some kind of population count. About 1300 B.C., Egypt was divided into administrative districts. The government registered and counted heads of households and members of the households within these districts.
The fourth book of Bible, the Book of Numbers, describes the census, or numbering, of the tribes in ancient Israel to determine the number of men of fighting age (Numbers 1: 1-46; Numbers 26: 1-51). In 594 B.C., the Greek lawmaker Solon introduced a form of enumeration and registration to reform tax laws in Greece.
The Romans employed census takers known as censors to determine the number of people who were eligible for taxation and military duty. The Roman censor was responsible for officially registering all citizens in a particular area, evaluating their property, collecting revenue, and guarding public morals. Perhaps the best-known Roman census is described in the New Testament story of the birth of Jesus Christ (Luke 2:1-7). This census took place about 5 B.C., when Joseph and Mary traveled to Bethlehem to record their names in a census ordered by the Roman emperor Augustus.
The practice of taking censuses declined in Europe after the fall of the West Roman Empire in A.D. 476. One of the few attempts to count people during the Middle Ages occurred in England in 1086. That year, commissioners sent by William the Conqueror traveled the kingdom and recorded, for tax purposes, the names of all English landowners and the value of their lands and houses, tenants, and servants. The resulting document, known as the Domesday Book, provides historians with a censuslike description of England at that time.
Through the years, with the rise in trade, the growth of towns, and the development of nations, rulers and government officials increasingly recognized the importance of counting people and goods. In 1665, King Louis XIV of France ordered a census in New France, in what is now Quebec, Canada. This census recorded the name of each person, along with such information as age, marital status, occupation, and relationship to the head of the household. The main purpose of this census was to collect information about the colony’s progress, rather than to assess how much military service or tax revenue the colonists might provide. Because of this purpose, census historians generally consider the New France enumeration to be the model for modern censuses. Likewise, in 1703, there was a house-to-house census in Iceland for reasons other than taxation and military service. This census inquired into the effects of economic conditions and natural disasters. The government then used the information to develop programs for economic and social improvement.
A number of European countries undertook censuses of individual cities and provinces in the early 1700’s. However, none of these enumerations counted the total population of a nation until 1749. That year, the Swedish government conducted the first national census.
The first modern census
—one that was complete, direct, and scheduled to be repeated at regular intervals—was the United States census of 1790. In the 1800’s, a number of other countries began taking regular censuses. In 1853, an International Statistical Congress was held in Brussels, Belgium. This conference represented the first attempt to adopt international recommendations and requirements to help in comparing population census data among various countries.
After World War II ended in 1945, censuses became especially important as an aid in planning for the economic reconstruction of countries that had been heavily damaged in the war. In 1946, the United Nations established a separate Population and Statistical Commission, which recognized the need for census statistics. Since then, the United Nations has published a number of principles and recommendations for population and housing censuses to assist countries in the planning of censuses. Following these recommended standards allows for international comparison of collected data. In addition, the United Nations Fund for Population Activities provides many countries with financial and expert assistance for the planning of censuses.
Today, most censuses are proclaimed by a government decree or law and planned and executed by a statistical agency, a permanent or semipermanent census bureau, or both. These census acts or laws require every person to answer the questions to the best of his or her knowledge. Refusal to cooperate can result in a fine or even imprisonment.
Some characteristics of today’s censuses
The most common type of census is the population and housing census. In general, this kind of census provides a count of the number of people a country has, as well as information on what types of dwellings they live in. Countries also regularly conduct censuses of agriculture, business, and manufacturing.
Censuses vary in a number of ways. Some censuses, called de facto censuses, count people where they are physically present at the time of the census. Generally, this means the place where people slept the night before the census date. Other censuses, called de jure censuses, count people where they usually live.
Some censuses make use of canvassers or enumerators, who go door-to-door to interview one or more members of a family or household. The enumerator records the answers for all household members. This method is used most often in countries with a largely illiterate or nomadic population. Other censuses rely on a method called self-enumeration in which a census form is distributed by census officials or sent through the postal system. A member of the household enters information on the census form and then returns the form to the census-taking agency.
Census forms.
Census or statistical offices use several types of question forms or questionnaires. Short questionnaires, for instance, record such basic information as the age of members of a household, their sex, and their marital status. Typically, this short form is sent to the majority of households. Long forms are received by only a small percentage of the population. These forms record more detailed information on employment, religion, income, disability, ethnic origin, education, and nationality. Demographers (people who study population) and statisticians use these long forms to calculate figures for the population as a whole even though the information was collected from only a sample—that is, a small group of people.
To count as many people as possible, census organizations produce forms in each of a nation’s official or major languages. They may also produce forms in languages spoken by small groups or immigrants. Many countries also attempt to conduct censuses of homeless populations, usually by counting people who use homeless shelters or soup kitchens.
The types of questions asked on a census form often reflect changes in society. In the 2000 census in the United States, for example, respondents were allowed for the first time to indicate more than one racial category. This change reflected a new awareness of the number of Americans of mixed racial heritage.
In most countries, the housing census is combined with the population census. Information on housing is either collected on a separate form or as part of the population questionnaire. Questions on the house or dwelling include number of rooms; bathroom facilities; water supply; availability of electric power; type of construction material; ownership of radio, television, or both; and monthly rent or mortgage payment.
Timing of a census.
The time in which the actual population count is performed is called the enumeration period. A number of factors can affect when to undertake a census. In Southeast Asia, for example, censuses do not take place during monsoon season. Harvesttime in agricultural areas or the observation of religious holidays can also affect the timing of a census.
Most countries have established a regular census date as a reference point. This census date varies from country to country, because each country picks a date that experts believe will provide the most accurate statistical picture of the population. A household is asked to report its place of residence, family size, and other conditions as they were on the census date—even if the family has since moved, had a birth or death, or otherwise changed. This reference date is important because the actual census taking may go on for days or weeks.
Census intervals vary. The United Kingdom, the United States, and India, for example, hold regular censuses every 10 years. Such censuses are called decennial censuses. Canada, New Zealand, and Ireland conduct quinquennial censuses—that is, they take a census every five years.
A number of countries no longer conduct censuses. For example, the Netherlands, Denmark, and Iceland rely on sample surveys and population registers for demographic information instead of taking censuses.
Censuses around the world
Although most countries that conduct censuses follow the UN guidelines, there are some variations in procedures from country to country. This section discusses censuses in some countries throughout the world.
The United States
collects more varied and complete census information than any other nation. The U.S. Constitution requires that a state’s representation in the House of Representatives be based on its population. To meet this requirement, the nation has conducted a population census every 10 years since 1790. The U.S. Census Bureau, an agency of the Department of Commerce, conducts all U.S. federal censuses. The Census Bureau conducts censuses of population, housing, agriculture, governments, and economic activity. 
The Census of Population
gathers such population data as the total number of people and their age, education, employment, income, marital status, race, and sex. The U.S. census counts people on a de jure basis. Since 1960, the Census Bureau has used a combination of enumerators and self-enumeration procedures.
The Census of Housing
has been conducted along with every Census of Population since 1940. It gathers various information for each housing unit—the year it was built; the number of rooms; the type of plumbing facilities and heating equipment; and the monthly rent or value of the home.
The Census of Agriculture,
begun in 1840, is conducted every five years. It gathers such information as the number of farms, the amount of crops harvested during the preceding year, the number of farmworkers, and the amount of irrigated farmland.
The Census of Governments
collects information every five years on counties, cities, villages, and other units of local government. This information includes the form of government organization, the number of people employed, and the financial arrangements of the government.
The economic censuses,
which the Census Bureau conducts every five years, cover construction, manufacturing, mining, retail trade, wholesale trade, service industries, and transportation. These surveys collect data on the output and resources of the various industries. The information includes the form of ownership, the volume of business, the size of the payroll, and the quantity and type of equipment available for use.
Canada
can lay claim to having established the model for modern censuses in 1666. That year, Jean Baptiste Talon, the representative of the French King Louis XIV in New France (now Quebec), personally went door-to-door to collect information from the colonists on age, sex, marital status, and profession or trade. The French conducted a total of 36 full censuses under their regime, the last one in 1739. The colonists were asked questions on livestock, crops, sawmills, churches, and possession of swords and firearms.
The British continued regular census taking in Canada under their rule. The British North America Act of 1867 (later called the Constitution Act) and the 1870 Census Act both provided for a decennial census.
In 1871, the Ministry of Agriculture conducted the first Canadian census after Confederation. It enumerated the populations of the provinces of New Brunswick, Nova Scotia, Ontario, and Quebec. In the census of 1881, British Columbia, Manitoba, and Prince Edward Island were also included. Other provinces and territories were added to the decennial counts in 1891 and 1901. Canada established a permanent census and statistics office in 1906. In 1956, Canada instituted a quinquennial census.
Canadian censuses are held on a de jure basis. The majority of people receive census questionnaires in the mail. Canvassing is used only in remote areas and on Indian reserves.
Mexico
created a statistical office in 1882 and conducted its first official census in 1895. Mexico began taking decennial censuses in 1900, but the 1920 census was delayed until 1921 due to fighting in the Mexican Revolution. Besides the usual questions on age, marital status, occupation, economic activity, and place of birth, some of the earlier Mexican censuses inquired about diet and whether or not a person wore shoes. The Mexican census in 1930 began counting people on a de jure basis.
Mexico’s housing census is combined with the population census. The nation has also carried out agricultural censuses at the same time as the population and housing census. Mexican censuses are conducted mostly through canvassing.
Mexico established the National Institute of Statistics, Geography, and Informatics in 1983. This body was designed to bring together activities related to collecting and distributing statistical and geographical information on the nation.
China
has a long history in carrying out population estimates. From about 1134 to 246 B.C., Chinese rulers often undertook population counts and registrations. During the Han dynasty, which lasted from 206 B.C. to A.D. 220, a series of annual estimates took place during harvesttime. Records were also collected during the Ming dynasty, which lasted from 1368 to 1644. These records included questions on landownership, family size, professions, and number of adults and children in a household. The first modern population census in China was conducted in 1953.
India.
The first census of India took place in 1871 and 1872, when the British ruled the region. Kashmir and some other areas were excluded from this first census. In 1881, the government of British India carried out the first complete census of population. India has had population and housing censuses every 10 years since then.
In addition to the usual questions on age, marital status, religion, occupation, and language, the censuses of India before 1951 requested detailed information on the castes, sects, and tribes to which a person belonged. Since 1951, the census has asked only if a person is a member of a scheduled caste or scheduled tribe. Scheduled castes and scheduled tribes are traditionally oppressed social groups or remote tribes. Such groups receive special consideration for government jobs and scholarships.
India promotes awareness of the importance of the census through announcements in movie theaters, a special postal stamp cancellation, posters, radio broadcasts, and discussions in schools and colleges. India began computerizing the processing of its census results in 1971. Most states and all territories have their own census offices under the direction of the Registrar General’s Office in New Delhi.
The Philippines.
One of the earliest population estimates for the Philippines dates from 1591. The estimate was based on the numbers of tribes counted. Additional estimates continued in the 1700’s and 1800’s, but only the Christian population was included, largely because these estimates were based on church records of marriages, baptisms, and burials. The first official census was carried out in 1878, while the Philippines were still under Spanish rule. Censuses were conducted in 1903 and 1918 under the administration of the United States.
The first census after World War II was carried out in 1948. To address the need for information on economic reconstruction of the country, a separate census schedule collected data on property damage sustained during the war. The Philippines added a housing census to the population census for the first time in 1960. Censuses of the Philippines count people on a de jure basis. Canvassers or enumerators collect the information. The National Statistics Office is responsible for collecting, compiling, and publishing census results and other demographic and economic statistics.
Australia
began counting its population as early as 1788 at gatherings called musters. The individual Australian colonies conducted their own censuses during most of the 1800’s. The Census and Statistics Act in 1905 provided for censuses of the entire country to be held every 10 years beginning in 1911. However, the regular census was not carried out in the early 1940’s because of World War II. Since 1961, censuses have been held every five years.
The Australian Bureau of Statistics is responsible for conducting the census. Australia counts its people on a de facto basis. It is self-enumerated, but the forms are delivered and picked up in person by Bureau of Statistics collectors.
South Africa.
In the 1600’s, the Dutch East India Company, a powerful Dutch trading firm, colonized the southern tip of Africa. The company carried out annual enumerations of population, livestock, and agricultural produce in the Cape Colony in what is now South Africa. The British continued this practice until 1856. One of the features of these censuses was the use of separate census forms for people of different races. Periodic censuses of Cape Province, the Orange Free State, the Transvaal, Natal, and Johannesburg were carried out in the years before South Africa became a republic in 1961.
The first census of population in South Africa after it became a republic was held in 1970. The nation now conducts a population census every five years, largely on a de facto basis. South Africa conducts its housing census with the population census. The nation’s statistical agency is called Statistics South Africa.
Mauritius.
Beginning in 1846, regular censuses were conducted in Mauritius while the island was under British administration. Decennial censuses were taken from 1851 to 1931. The pattern was interrupted by the outbreak of World War II in 1939. Census taking resumed in 1944, followed by censuses in 1952, 1962, 1972, 1983, 1990, and 2000. Beginning with the 1990 census, people have been counted on both a de facto and a de jure basis. Previously, the censuses in Mauritius were de facto.
The Central Statistical Office, established in 1945, is responsible for the collection of census data through a combination of self-enumeration and canvassing. Some of the topics included in the population and housing censuses of Mauritius are race, marital status, place of birth, education, nationality, religion, households, language or languages spoken, occupation, number of bedrooms, and principal materials of construction.
The United Kingdom
has conducted a census every 10 years since 1801, except for 1941, during World War II. In England and Wales, the Office for National Statistics is responsible for the census. The General Register Office for Scotland and the Northern Ireland Statistics and Research Agency carry out censuses in Scotland and Northern Ireland, respectively. Information is collected by self-enumeration and by canvassers. The United Kingdom census mostly counts people on a de jure basis.
