INTA 630: International Economic Development
LECTURE 7: POPULATION GROWTH I
Lecture 7: Population Growth and Development I
 Population Trends and Geographic Distribution of
the World’s Population
 Economic Models of Population Growth
 Is Population Growth Really a Problem?
 Policy Options to Influence Population Size and
Growth
Population Trends and Geographic
Distribution of the World’s Population
Source: http://www.worldometers.info/
Population Trends and Geographic Distribution
World Population by Country, 2012
Population Trends and Geographic Distribution
 History of World Population Growth (cont’d)
Estimated World Population Growth Through History
http://qed.princeton.edu/main/Image:Visualizing_World_Development_from_1960
Population Trends and Geographic Distribution
 History of World Population Growth (cont’d)
Population Trends and Geographic Distribution
 Structure of the World’s Population
- Geographic Distribution of World Population Growth
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Share of World Population by Region, 1750-2005
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Geographic Distribution of World Population, 2003 and 2050
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- World Population Density (Persons/Sq. Km)
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Fertility and Mortality Trends
» The rate of a given country’s population growth is measured as
the annual percentage net increase (or decrease) in population
size due to natural increase (excess of births over deaths) and
net international migration.
» Birth rates (fertility rates) in LDCs greatly exceed those of DCs.
World Birth Rates, 2011
(births per 1,000 population)
World Birth Rates, 2011
(births per 1,000 population)
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Fertility and Mortality Trends (cont’d)
World Death Rates, 2006
(deaths/1,000 population
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Fertility and Mortality Trends (cont’d)
» LDC death rates are also higher than those of DCs but not by
as much as birth rates.
» The large difference between DC and LDC growth rates is
explained by the large difference in rates of natural increase
(birth rates – death rates)
World Death Rates, 2011
(deaths/1,000 population)
World Death Rates, 2011
(deaths/1,000 population)
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Fertility and Mortality Trends (cont’d)
World Death Rates, 2006
(deaths/1,000 population
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Fertility and Mortality Trends (cont’d)
> Large differences in life expectancies between DCs and LDCs
World Life Expectancy at Birth, 2011
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Fertility and Mortality Trends (cont’d)
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
Fertility Rate vs. Real GDP per Capita (2009)
- Fertility and Mortality Trends (cont’d)
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Age Structure and Dependency Burden: Population Pyramids
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- Change in China’s Population Age Structure Over Time
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- The Hidden Momentum of Population Growth
» Population has built-in tendency to continue growing in LDCs
even after birthrates have declined for two reasons:
1.
2.
High birthrates cannot be altered overnight
High proportion of young people in the population
» Example: Population pyramids of Ethiopia and the U.S., 2005
- What do you conclude?
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- The Hidden Momentum of Population Growth (cont’d)
» An illustration: World Bank estimates of ultimate population size
for selected countries. What do you conclude?
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- The Demographic Transition
» The process by which fertility rates decline to replacement levels.
» Three stages of demographic transition (Western Europe)
Rapid
modernization
Early
modernization
Premodernization
Population Trends and Geographic Distribution
 Structure of the World’s Population (cont’d)
- The Demographic Transition (cont’d)
» Experience of contemporary developing countries
» Two general patterns (cases A and B):
Economic Models of Population Growth
 Malthusian Theory of Population
-
Reverend Thomas Malthus predicted that overpopulation would
inevitably lead to starvation, pestilence, and war.
"Human population grows exponentially, like compound
interest in a bank account, but farm output rises at a
slower, arithmetic rate; the result, human population will
inevitably and repeatedly outstrip its food supply."
“On the Principle of Population,” 1798.
- Malthus was wrong … BUT WHY?
Malthus Did Not Foresee:
1. Technological advances (yield increases through technological
innovation)
2. Growth of Trade Among Nations
3. Decline in Fertility Growth Rate and Death Rates as Countries
Develop and Incomes Increase
Economic Models of Population Growth
 Household Theory of Fertility
- Attempts to explain the observed falling birthrates associated
with stage 3 of demographic transition
-
Assumes that children are a consumption good
-
The decision to have children (fertility) is a rational economic
response to a couples’ demand for children relative to other
goods.
-
The demand for children is, thus, expressed as:


Cd = f(Y, Pc, Px, tx)
Cd
0
Y
Cd
0
Px
Where
Cd =
Y
=
Pc =
Px =
=
tx
Cd
0
Px
Cd
0
tx
demand for surviving children
level of household income
“net” price of children
price of all other goods
tastes for goods relative to children
Economic Models of Population Growth

What are the Implications of the Household Theory of
Fertility for Birthrates Among the Very Poor?
Birthrates among the very poor are likely to fall with:
1. An increase in the education of women and a consequent
change in their role and status
2. An increase in female employment opportunities
3. A rise in family income from employment or redistribution of
income
4. A reduction in infant mortality
5. The development of old-age or other social security systems
6. Expanded schooling opportunities for children