Some Basic Concepts Of Demographic Analyis

Some Basic Concepts of Demographic Analyis

1. Observation

Demographic facts and figures are assembled on. the basis of. the- observation of individuals and groups. Observations are conducted with naked eye -on the course of events which are opened. to conflicting influences acting concurrently. Observation can be of different types.

Human . beings are the’ objects of- observation. On whom controlled experiment is not possible as in physical sciences. The sense in which experiment is -possible in demographic study is that different populations can be studied at the same time and the same population �can be studied at different times. Observation requires sufficient skill, knowledge, expertise and judgment. Slight neglect or biased view can result in misleading conclusions. Demographic facts cannot have mathematical precision because of the intervention of exogenous factors. Changes taking place with time -and group cannot be properly observed, and quantified.

2. Relative Number

Students of population will be interested in collecting facts and establishing relations between sets of data and find out ratios and rates. Both ratios and rates - are relative figures and express a relation between two or more numbers. It is commonly felt that relative numbers are more useful or better than absolute numbers. But this opinion is not correct for all times and in all cases.

In certain cases absolute numbers can be more useful than relative numbers. Absolute numbers are raw data of population. Where comparison is indispensable or useful, relative numbers are’ needed, or-else absolute numbers can serve, the purpose.

3.Rates,

Rates ate used to observe demographic figures in a meaningful way Birth rates, death rates, marriage rites, etc , are used in demographic studies. Some of the Important: demographic rates are as’ follows:’

1. Crude birth �rate: The �number of live births in the. year, per 1,000 population at mid-year.

2.. Crude death rates: The number of deaths’ in the year, per 1,000 population at mid-year.

3 Crude marriage rate: The number of marriages (not persons marrying). in the year, per 1,000 population at mid-year.

4.Crude divorce rate:: The number, of divorces (not persons; divorcing) in the year, per 1,000 population’ at mid-’year.

5; Crude rate of: natural Increase: Difference.. between . the crude birth and death rates.

6. Abortion Rate: The estimated, �number.. of abortions per1,000.women aged l5-44.years in a given year. , .

7, Age-specific, rate: �Rate ,obtained. for specific age groups for example, age-specific fertility rate, death rate, marriage rate, illiteracy rate, school enrolment rate, etc.).

8’. General fertility rate: The number of live births per 1,000 women aged 15.44 years in a g yen year.

9. Gross Reproduction Rate (GRR): The average number of daughters that would be born alive to a woman (or group of women) during her life’ tine if she passed, through her child- bearing years conforming to the age-specific fertility rates of a given year. See net reproduction rate arid total fertility rate.

10. Growth rate: The rate at which, a population is increasing (or decreasing) in a given. year due to natural increase and net migration, expressed as a percentage of the base population.

11. Infant mortality rate: вЂ?The number of deaths of infants under one year of age in a given year perвЂ™Ð²Ð‚?1,000 live births in that year.

12. Maternal mortality rate: The number of deaths to women due to pregnancy and child-birth complications per 100,000 live births in a given year. �

13. Marriage rate (or crude marriage rate): The number of marriages per l000 population in a given year.

14. Martial fertility rate: The number of Legitimate’ live births per 1,000 married women aged 15-44 years in a given year. �

15. Net’ migration rate: The net effect of immigration and emigration on an area’s population, expressed as increase or decrease per 1,000 population of the area in a given year.

16. Net reproduction rate (NRR): The average number of daughters that would be born to a women (or group of women) if she passed through her lifetime from birth conforming to the age-specific fertility and mortality rates of a given year. This rate is similar to the gross reproduction rate, but takes into account that some women will die before completing their chi1d baring years.: An NRR of 100 means each generation of mothers is having exactly enough daughters to replace itself in the population. See gross reproduction rate, total fertility rate, and replacement level fertility.

17. PerinÐ"ÐŽtal mortality rate: The number of foetal deaths after 28 weeks of pregnancy (late foetal death) plus the number of deaths V to infants under 7 days of age per 1,000 live births.

18. Postneonatal mortality rate:. The annual number of infant deaths at 28 days. to one year of age per 1000 live births in a given year.

19. Survival rate: The proportion of persons in a specified group (age, sex, health status, etc) alive at the beginning of an interval (e.g., a 5-year period) who survive to the end of the interval.

20. Total Fertility Rate (TFR). The average number of children that would be born alive to a woman (or group of women): during her lifetime if she were to pass through her child bearing years conforming to the age-specific fertility rates of a given year. See also gross reproduction rate and net reproduction rate.

4. Ratio

Ratios differ from rates. A rate counts the number of events in a restricted time period, for example, one year and would be only half that value for a half year. A ratio prevails at a particular point in time, and in this sense it is a prevalence concept rather than the incidence concept underlying a rate.

1. Abortion ratio: The estimated number of abortions. per 1,000 live births in a given year.

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