Census and its Characteristics & Method pros n cons

A census is the procedure of systematically acquiring and recording information about the members of a given population. It is a regularly occurring and official count of a particular population.  The term is used mostly in connection with national population and housing censuses; other common censuses include agriculture, business, and traffic censuses. The United Nations defines the essential features of population and housing censuses as "individual enumeration, universality within a defined territory, simultaneity and defined periodicity", and recommends that population censuses be taken at least every 10 years. United Nations recommendations also cover census topics to be collected, official definitions, classifications and other useful information to coordinate international practice.

These censuses have four main characteristics:

• Universality: The census should cover the territory of the entire country, which ensures that all persons and all housing units are included. Sometimes, this goal is not achievable, for instance, if parts of a country experience conflict or if there are special population groups that are hard to enumerate, such as nomadic people. In those cases, a census may be complemented by statistical sampling.
• Individual enumeration: A census requires that each person or dwelling unit is enumerated individually so that their characteristics are captured separately. This facilitates cross-tabulation of census indicators and compilation of information for small areas.
• Simultaneity: A census is representative of the status at a specified time, usually a single day or a period of a few days in which the information is collected. Some questions, such as the birth or death of family members, refer to a longer reference period, such as the year before the census. A census is defined as de facto if it records persons according to their actual location at the time of enumeration or de jure if persons are referenced at their usual place of residence. This distinction can make a significant difference, for example, in countries with many temporary migrant workers.
• Defined periodicity: An important purpose of a census program is to provide information about changes over time. For instance, demographic projections tend to rely on information from two or more censuses. A census should therefore be conducted at regular intervals. Because of the large cost involved, most countries conduct censuses only every 10 years, although the periodicity is less regular in many developing countries.

Canvasser Method or Direct Interview Method of Census:

In this method, there are two method:

1. De facto Method

2. De jure Method:

(a) De facto methods: A de facto census is one that counts all persons as residents of the place they happen to be at the time the census is taken. In practice, de facto censuses are conducted in such a way that most people are counted in the places they usually live, but not always.

Advantage: Very clear and simple, international comparison are easy, the time taken is short and the information obtained is reliable.

Disadvantage: Floating population not counted, large number of trained and qualified personnel is required and mistakes occur because of rapid and fast method o f enumeration.

(b) De jure methods: When a de jure census is taken, there is always some uncertainty abut what should be considered a person's usual or normal place of residence.

Advantage: Due to availability of sufficient time, inaccuracies are reduced to the minimum, more questions can be asked, and the information obtained is dependable.

Disadvantage: Difficulty arises in the definition of temporary, and permanent, birth and death goes uncounted between the periods and it is difficult to count persons who have no permanent address.

Advantages of census

• provides a true measure of the population (no sampling error)
• benchmark data may be obtained for future studies
• detailed information about small sub-groups within the population is more likely to be available
• helps to make life table
• can predict the future population 

Disadvantages

• may be difficult to enumerate all units of the population within the available time
• higher costs, both in staff and monetary terms, than for a sample
• generally takes longer to collect, process, and release data than from a sample
• difficult to conduct census in war affected areas
• difficult to conduct due to geographical condition