A census is the procedure of systematically acquiring and recording information about the members of a given population. The word ‘census’ originated from the Latin word ‘censere’, meaning to estimate; however, use of census has panned over time in terms of scale and depth.
In ancient Rome, a census was undertaken to maintain a list of adult males fit for military service and thus used for enumerating only a subset of a larger populace. Regions like China, Egypt, Athens and Rome practiced ‘almost censuses’ in ancient times which excluded enumeration of women, children and slaves. These were largely held for purposes of taxation, military conscription, economic and class control of the social structure with a view to strengthen the central government.
Many biblical accounts also indicate the practice of population enumeration in ancient times. Babylonia in the 40th century BC, saw the usage of a census to ensure food security for its people. The records were maintained in stone tablets. In the 15th century, the Inca Empire followed a unique way of recording census information. They did not have any written language but recorded information collected during censuses on quipus, strings from llama or alpaca hair or cotton cords with numeric and other values encoded by knots in a base 10 positional system.
Population enumeration methods have been known in India from the times of the earliest literature, the Rig Veda. In the 3rd century BC during the reign of the Mauryas, the book Arthashastra by Kautilya laid the principles of government based on an excellent account of population statistics used for taxation and elaborated on methods of population, economic and agricultural censuses.
Similar records exist for most countries world over and illustrate how censuses have been put to variegated use. The most accurate population enumeration of the Middle Ages is believed to be the one done under the Han Dynasty in 2nd century AD of China, whereas the most famous census in medieval Europe is the Domesday Book, undertaken in 11th century AD by William I of England to ensure proper taxation of the conquered land. Germany also undertook an almost accurate census in 15th century AD under the threat of a siege, to calculate the amount of food that would be required. A census was undertaken by a priest in the Mayan land of Cozumel in 16th century AD to enumerate indigenous population of the area.
Modern World Censuses
With the advent of industrial revolution and modernisation, the European region in the 17th and 18th centuries underwent a major demographic change. Following this, modern world censuses started to be held encompassing principles of individualism, universality, simultaneity and periodicity with systematised collection of basic information. The purpose, accuracy and legal safeguards of enumeration also improved post World War II due to concerted efforts of the United Nations which streamlined topics for sampling further as geographical, familial, demographic, socio-political and educational with subsets of derived topics. Today, the entire world’s population is enumerated once every decade as per a country’s established standards. Evolved technology and statistical tools have made this mammoth job relatively manageable and contributed immensely to expanding administrative databases.
According to the United Nations Statistical Division, as of November 2010, 192 countries had already conducted a census, covering around 89 per cent of the world population; 36 had scheduled the process while the remaining 7 countries were not likely to carry out a census in the recent future.