Origins
Census-taking—counting and categorizing populations—is among the oldest state functions. Ancient Babylonian clay tablets, Egyptian papyri, and Chinese bamboo records document population counts. Biblical accounts describe census-taking (Numbers, 2 Samuel). The Roman census (from census, meaning assessment) combined population counting with property valuation for taxation and military purposes. Wherever states needed to know their populations—for taxation, military conscription, or administration—they developed enumeration practices.
Modern census development combined traditional counting with statistical sophistication. European states systematized census-taking in the 18th and 19th centuries, moving from ad hoc surveys to regular, comprehensive enumerations. The US Constitution (1787) mandated decennial census for apportioning congressional representation—perhaps the first constitutional census requirement. Census bureaus became permanent institutions, developing standardized questionnaires, enumeration procedures, and data processing techniques. The census became both governmental tool and social science data source.
Census categories have always been politically significant. What questions to ask—about race, ethnicity, religion, occupation, housing—reflects governmental interests and shapes how populations are understood. Census categories can create or reinforce social divisions (as with racial classification) or obscure them (as when categories fail to capture relevant distinctions). The politics of census design—what to count and how—has generated controversy throughout census history.
Structure & Function
Modern censuses systematically count and characterize populations at regular intervals (commonly decennial). The enumeration typically aims for complete coverage—counting every person within a territory. Questions address demographic characteristics (age, sex, household composition), social indicators (education, occupation, income), and housing conditions. Special procedures address hard-to-count populations (homeless, irregular migrants, institutionalized persons). The collected data undergo processing, verification, and publication.
Census administration requires substantial infrastructure. Census bureaus maintain permanent staffs that plan, conduct, and analyze enumerations. Temporary workforces (sometimes millions of enumerators) collect data during census periods. Data processing has evolved from hand tabulation to mechanical tabulation (Herman Hollerith’s tabulating machine for the 1890 US census) to modern computer systems. Sampling techniques supplement complete enumeration, enabling more detailed questions for representative subsets.
Census data serves multiple purposes. Official purposes include legislative apportionment, redistricting, and allocation of governmental resources. Planning purposes use population data for infrastructure, services, and development decisions. Research purposes employ census data for demographic, economic, and social analysis. Commercial purposes use census data for marketing and business planning. The census thus provides foundational knowledge about populations that government, researchers, and businesses all depend upon.
Historical Significance
Censuses enabled modern state capacity by providing knowledge essential for governance. Without knowing population size, composition, and distribution, states cannot effectively tax, conscript, plan, or allocate. The census created “legible” populations that states could manage. This capacity has served both beneficial purposes (service provision, planning) and harmful ones (surveillance, persecution). Census data identified populations for both service delivery and exclusion.
Census categories have shaped social identity. Official classification creates administrative realities: people are “counted as” members of categories that may not match self-understanding. Racial classification in censuses has been particularly consequential—defining who counts as what race for purposes from segregation to affirmative action. The politics of census categories—who is visible, how groups are defined, what distinctions matter—reflects and shapes social relations.
Contemporary censuses face technological transformation and public skepticism. Digital data collection, administrative records linkage, and big data analytics may supplement or replace traditional enumeration. Privacy concerns and political distrust generate resistance to census participation. The 2020 US census controversy over citizenship questions illustrated how census design remains politically contested. Yet the function remains essential: governing populations requires knowing them, and the census remains the primary mechanism for producing that knowledge.
Key Developments
- c. 3800 BCE: Babylonian population records
- c. 3000 BCE: Egyptian census records
- 2 CE: Chinese census under Han dynasty
- c. 500 BCE: Roman census institutionalized
- 1085: Domesday Book; Norman England survey
- 1666: Quebec census; first systematic colonial census
- 1749: Swedish population register begins
- 1787: US Constitution mandates decennial census
- 1790: First US census conducted
- 1801: First British census
- 1853: First international statistical congress
- 1890: Hollerith tabulating machine; mechanical processing
- 1902: US Census Bureau made permanent
- 1948: UN Statistical Commission promotes census standards
- 1960: UNIVAC computer processes US census
- 2000: Internet response option introduced
- 2020: COVID-19 and citizenship question controversies affect US census