Population pyramids provide a pictorial representation of the age and sex composition of a population by displaying demographic data. They show births, deaths, and migration. Developed countries typically have a narrow base and bulge in the middle representing lower birth rates and more people living longer. Developing countries often display a broad base, narrow top, and high dependency ratio due to higher birth rates and shorter lifespans. The demographic transition involves countries shifting from high birth and death rates to lower rates as development increases.

3. DEMOGRAPHY

4. POPULATION PYRAMIDS
 Pictorial presentation of 3 Factors (Influence
Population)
Births
Deaths
Migration

5. Features (Population
Pyramids)
In terms of its composition by:-
 Age, Sex
 Males (on Left side)
 Females (on Right side)
 Children (at bottom)
 Elders (at Top)
 Adjoining bars
(contribution of each age, Sex group)

6. EXAMPLE
Developing Developed
Country Countries
(Pakistan) (Sweden)
Base: Narrow (Low Birth
Base: Broad (High Birth rate)
rate) Middle: Bulge (Convex border)
Top: Narrow / Acute apex Top: Obtuse apex
(No: of Elders (Less) (More Elders)
Low Dependency rate
High Dependency rate Good effect (on Economy)
Bad effect (on Economy) Productive ( More than Half
Unproductive (Half Pop)
Pop) Under 15 Ys: ---- 25% Pop:
Under 15 Ys: ---- 44% Above 15 Ys: ---- 75% Pop:

7. PAKISTAN
SWEDEN

8. WORLD POPULATION

9. PAKISTAN

11. DEMOGRAPHIC
CHARACTERISTICS
Population unevenly distributed with
very densely populated very sparsely populated
areas areas.
 All countries in region have a positive rate
of natural population change.

12. DEMOGRAPHIC TRANSITION
Two demographic worlds
Less-developed counties represent 80% of the world population, but more than 90% of
projected growth
Richer countries tend to have negative growth rates.
Growth Rate (%) Grading of population increase
0 ( Zero) Stationary Growth (No Growth)
0 to 0.5 Slow Growth
0.5 to 1 Moderate Growth
1 to 1.5 Rapid Growth
1.5 to 2.0 Very Rapid Growth
>2 Explosive Growth ( Population
explosion) OR Population Bomb

13. DEMOGRAPHIC
TRANSITION
3 TYPES
1. Old balance
Fertility Mortality
2. New balance
Fertility Mortality
3. Imbalance
Fertility Mortality

14. DEMOGRAPHIC CYCLE
Population
Grows
rapidly Germany,
Hungary
(after effect of
India in II world war)
Population
1920-1930 Population Becomes Population
Grows stationary
Population declines
slowly
stationary Many
countries China,
of S. Asia & Singapur
Africa Pak in 1970

15. Demographic Transition Accompanying
Economic and Social Development
B
Birth
Rate
Death
Rate
15

17.  Note that in English, fertility refers to actual
births.
 Fecundity refers to the biological ability to
have children (the opposite of sterility).

18. Dependency Ratio
 The dependency ratio tells us how many young people
(under 16) and older people (over 64) depend on people
of working age (16 to 64). The dependency ratio is
worked out with this formula.
 Dependency Ratio = % under 15 + % over 65 ys: X 100
 % between 15 & 64
 A worked example should make this clearer. Pakistan,
which is a developing country, has 41% of its population
less than 15, and 4% over 65. This makes 55% (100 -
(41+4)) between the ages of 15 and 64.
 Dependency Ratio = 41 + 4 X 100 = 81.8
 55