Transcript Population Fertility

1. POPULATION IN TRANSITION
IBDP Expectations:
 Population Change:


Explain population trends and patterns in births
(Crude Birth Rate), natural increase and mortality
(Crude Death Rate, infant and child mortality rates),
fertility and life expectancy in contrasting regions of
the world. Analyse population pyramids. Explain
population momentum and its impact on population
projections.
POPULATION FERTILITY
Crude
The most common measure of fertility.The
Birth Rate number of births, per 1000 people in the
(CBR)
population, per year. All the population is
considered. Numbers like 10, 20, 40, etc.
Rates of 30+ /1000 are HIGH
Rates of below 13/1000 or LOW
General
Fertility
Birth
(GFB)
This in an indicator of the number of likely
births. It is an index of the number of live
births in a year divided by the number of
women aged between 15 and 49.
Total Fertility Rate
The average number of
children born to a woman during her lifetime.
 Number of live births per female of reproductive age
(15-49).
 Numbers such as 2.2, 4.5.
 Indicates population change over a long period of
time.
 Instructive about societal norms in any given
culture.
 A TFR of 2.1 is considered as being the replacement
birth rate.
 Lower than 2.1 yields population decrease while
rates greater than 2.1 yields population increase.
 Improvements in medical conditions lower the
replacement rate (below 2.06 in many countries).
Crude Birth Rate
25 males of any age
25 females of any age
10 children born that year
TOTAL FERTILITY
RATE
25 females between 15-49
10 children born that year
1,000
1,000
30
CBR = 30
60
TFR = 2.04
= (60/1,000) * (49-15)
TOTAL FERTILITY RATE, 1994-2000
What is the trend?
Replacement rate (2.1)
FACTORS AFFECTING FERTILITY RATE
Biological
Determinants
Social- Cultural
Determinants
Fertility
Economic
Determinants
BIOLOGICAL DETERMINANTS
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Biological determinants
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Age:
Reproductive age of women ranges from 15-44 or from 15-49.
 Men: 13-??
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Health and nutrition:
Poor health and/or nutrition can reduce fertility.
 Linked with underweight children.
 Linked with child mortality rates.
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Environment:
Represents an undocumented impacts on fertility.
 Stressed populations tend to have less males than females.
 Possible correlation between sperm count and pollution.
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SOCIAL DETERMINANTS
 Social
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determinants
The social norms and acceptance of practices affecting
fertility.
Differ from society to society.
Marriage:
Particularly the average age of marriage.
 The percentage of people never married varies spatially and affects
fertility rates.
 Late marriage age generally involves less children.
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Contraception:
Used by 30-50% of all married couples.
 Availability of contraceptive devices and social attitudes toward
their use affect fertility rates.
 Sharp differences exist between MEDCs and LEDCs.
 Some notable exceptions, such as China and Cuba.
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SOCIAL DETERMINANTS (CONTINUED)
 Abortion:
Last resort measure when contraception failed (or was not
used).
 Its legality is not universal and under challenge in some
countries where it is permitted.
 Global figures (1999):
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210 million pregnancies.
 22% of all pregnancies end up in a abortion.
 46.2 million abortions, of which 20 million procedures are obtained
illegally.
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Illegal abortions are common in most societies, even where
it is prohibited.
Culture plays an important determining role in the impact
of abortion.
United States: 49% all pregnancies unwanted and about
half of unwanted pregnancies ended in abortion (1.4
million abortions per year).
ECONOMIC DETERMINANTS
The role of children, or their “value” affects fertility.
 Inverse relationships:
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Fertility and income per capita.
 Fertility and urbanization.
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Traditional rural societies:
Children still play an important economic role and contribute to family wealth,
 Fertility is likely to remain higher.
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Industrial and post-industrial societies:
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Costs tend to increase with the development level of the society. Deflate the
fertility rate since parents must consider the direct and opportunity costs of
bearing additional children.
FACTORS AFFECTING FERTILITY RATE
 Status
of Women
 Level of education
 Employment opportunities
 Type of residence
 Religion of parents
 Level of available health care
 Machismo
 Perceived cost of having children
 Pressure from the government
WORLD FERTILITY RATE
STRONGLY CORRELATED WITH LEVEL OF ECONOMIC
DEVELOPMENT
Spatial distribution Fertility
QUESTION
How does birth rate affect population size?
What other factors affect a region’s population size?
TEXTBOOK P. 1 & 2