Basic outline of Theoretical perspectives: Fertility, Mortality, Migration

1. PRESENTED BY:-
SOURAV PATHAK
RAMAKRISHNA MISSION VIVEKANANDA EDUCATIONAL
and
RESEARCH INSTITUTE
Morabadi  Ranchi

2. 
A. Fertility
B. mortality.
C. Migration.
Are the three important determinants of
population growth.
Components of population growth
2

3.  Fertility is “the average number of children that would be born to a
women, if she experiences the current fertility pattern in her lifetime.
 According to Thomson and Lewis, “Fertility is generally used to indicate
the actual reproductive performance of a women or a group of women.
A. FERTILITY
3

4.  Fecundity, on the other hand, has a different meaning, if a female is able
to conceive, then she is said to be fecund. In fact, fecundity is the capacity
of a man and women to produce a live child.
 In ancient times, both the words, ‘still birth’ and ‘life birth’ were used.
 But at present , the word ‘birth’ is being is used only for ‘live birth,.
Cont.…
4

5. A.1) Crude Birth Rate (CBR)
A.2) Fertility Ratio (FR)
A.3) General Fertility Ratio (GFR)
A.4) Age Specific Birth Rate (ASBR)
A.5) Total Fertility Rate (TFR)
A.6) Reproduction/Replacement Rate (RR)
Measures of fertility
5

6. 
 The number of births per thousand population in a given year
is called Crude Birth Rate, which are related to total population.
 In the words of Thomson and Lewis, “The crude birth rate for
any specified population is obtained by dividing the number of
births recorded in that population during a specified year by its
total number , which gives a fraction of a birth per person.
A.1) Crude Birth Rate (CBR)
6

7. 
Crude birth Rate or CBR = B/P X K
where,
B= Total live births during a given year.
P= Total population at the middle of the same
year.
K=1000
Cont.…
7

8. 
In other word,
CBR= Number of live birth in a given year X 1000
Mid year population
If the population of any area is 50,000 and the number of children born are
700 then,
CBR= 700/50,000 X 1000
= 14
It shows that the CBR per 1000 population is 14
Cont..
8

9. 
 CBR are different in any country at different times, because CBR is
calculated after a particular month of the year.
 moreover, the data for live births is based on the registered birth, but all
births are not registered generally.
 Further, this measure of CBR is not satisfactory because fertility is related
to women and not to the whole population.
 Thus it is not a crude measure of fertility of a country.
Some key point about CBR
9

10.  It is calculated by talking into account only the females in reproductive age
group (age group 15-49).
 Expressed in terms of numbers of children below 5 years of age per 1000
female of reproductive age group.
FR= P / PF X 1000
where,
P= Number of children below 5 years.
PF= Number of females in reproductive age group (15-49)
A.2) Fertility Ratio
10

11. 
 Cannot be tabulated for a year other than the census year
because basic data are available from census age tables only.
 It includes only the surviving children below five years of age
and not all children who are actually born.
 It takes into account all females in 14-49 age groups irrespective
of their marital status.
Disadvantages of FR
11

12.  The number of children born per thousand females in the age group of 15-49
years, is called General Fertility ratio.
 According to Thomson and Lewis, “General Fertility ratio denotes the
number of births per thousand women of child bearing age”
Calculation:- GFR= B/PF X K
Where,
B= Total live births during a given year.
PF= Number of females of age group 15-49.
K= 1000
A.3) General Fertility Ratio
12

13. 
If the number of females of age group 15-49 is an area is 5000 and the total live
births is 200 in an area than,
GFR = 200/5000 X 1000
= 40
 lt indicates that there are 40 birth per 1000 women in the child bearing age
group.
Thomson and Lewis regard this measure batter than the Crude birth rate on
two counts :-
 It eliminates the influence of differences between males and females in
the total population.
 It eliminates differences in the proportion of women in 15-49 age
group.
Cont.….
13

14. 
 There is only partial standardization for age as the population
differs even within the 15-44 age group with respect to child
bearing incidence.
 Child bearing rate is appreciably higher in 20-29 of age than in
15-19 and 30-44.
 Such a fertility rate will be of little utility in countries where the
incidence of illegitimacy is large.
Disadvantages of GFR
14

15. 
 Age specific fertility rate is another refinement of birth rate.
 When the number of live births to women of definite age group per year
is divided by the total number of females of that age group only and
multiplied by 1000. we get the age specific fertility rate.
Formula:- APFR= BF/PF X K
Where,
BF= Number of live births to women of a specific age group.
PF= Mid-Year women population in the same age group.
K= 1000
A.4) Age Specific Fertility
15

16. If the number of live births to women in the age group 25-29 is 200 and the
number of women in this age group is 1200,
Then the APFR = 200/1200 X 1000
= 166.7
Cont..
16

17. 
In computing the age specific fertility rate, the age group of 5 years interval is
taken. This ASFR is considered better then other measure because ---------
1) It provide age specific fertility rates for different age groups.
2) It shows changes in the reproduction capacity of women in different age
groups.
3) It helps in analyzing a frequency distribution of birth among women in
specific age groups.
4) We can also calculate age specific fertility rate in relation to only married
women which is called age specific marital fertility rate.
5) It is the basis for calculating the total fertility rate.
Cont…
17

18. 
 This is regarded as the most meaningful measure
 The total fertility rate is the sum of age specific groups.
Formula for TFR=
Sum of age specific fertility rate X Magnitude of the age group
1000
A.5) Total Fertility Rate
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19. 
Age Group
(1)
No. of Births
(2)
No. of women
(3)
Age specific fertility
rate
(2)÷(3)X1000
15-19 20 100 20.0
20-24 80 200 400.0
25-29 90 220 409.1
30-34 85 210 404.8
35-39 75 190 394.7
40-44 50 170 294.1
45-49 5 150 33.3
For batter understanding of ASFR and TFR
Sum of ASFR = 1956
19

20. 
Sum of ASFR= 1956
Magnitude of age group = 5
Then,
Total fertility rate = 1956 X 5 ÷ 1000
=9.78
Cont…
20

21. 
 Indicates the replacement of individuals by others of the same age groups.
 Replacement rate supposes that one woman dies after giving birth to one
female who has the same degree of fecundity and also does not die before
the reproductive age.
 Female babies born per thousand of female population in the reproductive
age group.
 RR= Bf/Pf 15-44X 1000
 Bf is no of female babies born and Pf is no of females in
reproductive age group.
A.5) Reproduction/Replacement Rate
(RR)
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22. 
 Mortality means death.
 Death is defined as ”the permanent disappearance of all evidence of life at
any time after birth has taken place”. (UN, principles of a vital statistical
sysyem,1950 )
 Thus death does not include abortions and still birth.
 The study of causes and measure to reduce mortality are very important in
demography which can be analyzed in terms of the death rates.
B. MORTALITY
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23. B.1) Crude Death Rate (CRD)
B.2) Death Age Specific Rate (DASR)
B.3) Infant Mortality Rate (IMR)
B.4) Maternal Mortality Rate (MMR)
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Measure of mortality

24. 
The crude death rate is the number of deaths per 1000 people in a year in
relation to the total population.
CRD= D/P X K
Where,
D= Total registered deaths in a year.
P= Total mid-year population of that year.
K= 1000
If the total mid-year population of an area is 50,000 and the number of deaths
is 500.
Then,
CRD=500/50,000 X 1000
= 10
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B.1) Crude Death Rates (CRD)

25. 
 It is combines the death rates of different age groups. So it fails to give a
correct measure of mortality because in less developed countries infant
mortality rates and maternal death rates and old people death rates are
high.
 It is also not possible to make inter-regional comparisons in a country due
to variations in death .
 The sources of data for population and death are different. The population
are based on census and that of deaths on registration authorities. This is
unscientific.
In order to overcome the 1st two limitation , age specific deaths
rate and infant mortality rate are calculated.
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Drawbacks of CRD

26. As the death rates in the case of infant and old people are high and that of
young people are low, it is advisable to classify people under different
categories according to there age groups.
Formula for ASDR= DA/PA X K
Where,
DA= Number of deaths in a particular age group.
PA= Mid-year population of the age group.
K= 1000
N:B- While calculating the age specific death rates, the age group of 5 years
interval is taken such as 0-4, 5-9, 10-14, 15-19 years, etc.
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B.2) Age Specific Death Rate (ASDR)

27. 
 A child in the age group of 0-1 is called an infant.
 According to Barclay, “Infants are defined in demography as an exact age
group, namely age ‘Zero’, or those children in the 1st year of life, who have
not yet reached age one”.
Formula for calculating IMR= D1/B X K
Where,
D1= Number of deaths among infants registered during the year.
B= Number of registered births in the same year.
K= 1000
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B.3) Infant Mortality Rate (IMR)

28. 
Many factors are responsible for infant mortality. They are endogenous and
exogenous factor ---
1. Endogenous Factors:
 Age of mother
 The order of pregnancy or birth.
 Period of spacing between two births.
 pre mature birth.
 Weight of infant at birth.
These factors lead to deaths of infant who do not complete 4
weeks of life.
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Causes of Infant mortality

29. 
2. Exogenous Factors:
 These factors relate to post-neo-natal growth of those infants who die
between 28 days and one year of life.
 They are caused by diseases of respiratory, circulatory and digestive
system
 Lack of medical facilities
 Malnutrition
etc…..
29
Cont..

30. 
 MMR has great significance in societies of low socio economic
development where the process of child bearing is very frequent.
 It refers to the women dying due to the causes related to pregnancy,
delivery and any other maternity reasons.
 Expressed as female deaths due to maternity causes per ten thousand live
births.
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B.4) Maternal mortality rate (MMR)

31.  Like fertility and mortality, migration holds a prominence place in
demographic analysis of any area.
 It cannot be considered a mere shift of people from one place to another.
 Bogue (1959) considers a movement of people as an instrument of cultural
diffusion and social integration that results into more meaningful
distribution of population
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3. MIGRATION

32. 
It is not merely a reallocation of human resources but is a process which
has a three fold impact:
 On the area experiencing in-migration
 On the area experiencing out migration
 On the migrant itself.
Hence, whenever migration takes place in whatever form, it modifies the
area of origin, destination and way of life of migrants.
 Of the three major components Migration is the most difficult to
conceptualize and measure.
 Unlike fertility and mortality,, migration is not just an unequivocal
(undeniable/Obvious) biological event but a physical and social
transaction.
32
Cont…

33. 
 All movements are selective:
 A migrant who takes decision to move from one place to another may be
age selective implying that the people belonging to certain age group move
largely due to economic motives.
 At times people of the working group happen to be head of the family, so
the family may move with them.
33
Cont…

34. 
Immigration and Emigration:
When people from one country move permanently to another
country . For example, if people from India move to America then for
America ,it is terms as immigration, where as for India it is termed as
Emigration.
In- migration and out- migration:
In- migration means migration occurring within an area only,
while out migration means migration out of the area. Both types of
migration are called internal migration occurring within the country.
Migration from Bihar to Bengal is in- migration.
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Types of Migration

35. 
Gross and Net Migration :
During any time period, the total number of persons coming in
the country and the total number of people going out of the country for
residing is called Gross migration. The difference between the total number
of persons coming to reside in a country and are going out of the country for
residing during any time period is called Net migration.
Internal Migration and External Migration :
Internal migration means the movement of people in different
states and regions within a country from one place to another. On the other
hand, external or international migration refers to the movement of people
from one country to another for permanent settlement.
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Cont…

36. 
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