A comprehensive revision for Cambridge AS Geography, chapter 4 Population, subchapter 4. 2 Demographic Transition

1. ASGEOGRAPHYREVISION
POPULATION
4.2 DEMOGRAPHICTRANSITION

2. KEYTERMSANDDEFINITIONS
Demographic transition is the historical shift of birth and death rates
from high to low levels in a population. Crude birth rate (generally
referred to as the ‘birth rate’) is the number of births per thousand
population in a given year. It is only a very broad indicator as it does not
take into account the age and sex distribution of the population.
Crude death rate (generally referred to as the ‘death rate’) is the
number of deaths per thousand population in a given year. Again only a
broad indicator, as it is heavily influenced by the age structure of the
population.
Rate of natural change is the difference between the birth rate and the
death rate. Natural decrease is when the number of births is lower
than the number of deaths.

4. KEYTERMSANDDEFINITIONS
Ageing of population (demographic ageing) is a rise in the median age
of a population. It occurs when fertility declines while life expectancy
remains constant or increases. Development is the use of resources to
improve the quality of life in a country.
Human Development Index is a composite index of development
devised by the United Nations in 1990 incorporating a life expectancy, b
educational attainment and c GDP per capita at purchasing power
parity. Child mortality rate is the number of children who die before
their fifth birthday per one thousand live births.
Maternal mortality is the death of a woman during or shortly after a
pregnancy. Life expectancy (at birth) is the average number of years a
person may expect to live when born, assuming past trends continue.

6. KEYTERMSANDDEFINITIONS
Although the birth and death rates of no two countries have changed in
exactly the same way, some broad generalisations can be made about
population growth since the middle of the eighteenth century. These
generalisations are illustrated by the model of demographic transition.
Critics of the demographic transition model see it as too Euro-centric
as it was based on the experience of Western Europe.
There are a number of important differences in the way that
developing countries have undergone population change compared to
the experiences of most developed nations before them.

8. Sex ratio is the number of males per 100 females in a population.
Dependency ratio is the ratio of the number of people under 15 and
over 64 years to those 15–64 years of age.
Youth dependency ratio is the ratio of the number of people 0–14 to
those 15–64 years of age.
Elderly dependency ratio is the ratio of the number of people 65 and
over to those 15–64 years of age.
TOPICSUMMARY

9. TOPICSUMMARY
The world’s population is ageing significantly. Ageing of population
(demographic aging) is a rise in the median age of a population. It
occurs when fertility declines while life expectancy remains constant or
increases.
The problem of demographic ageing has been a concern of developed
countries for some time, but it is now also beginning to alarm
developing nations.
Development, or improvement in the quality of life, is a wide ranging
concept. It includes wealth, but it also includes other important aspects
of our lives.

10. TOPICSUMMARY
There has been much debate about the causes of development.
Detailed studies have shown that variations between countries are due
to physical geography, economic policies and demography.
In 1990 the Human Development Index (HDI) was devised by the
United Nations to indicate levels of development in countries.
The HDI contains three variables: life expectancy, educational
attainment and GDP per capita.
Demographic indices change over time as countries undergo economic
development.

11. ADDITIONALWORK
1. At what stage of demographic transition is the country in which you
live? Obtain data and graphs to show how this country has moved
through demographic transition.
2. Find population pyramids to show demographic ageing over time in
one country.
3. Produce data to show how life expectancy has changed in the
country in which you live.

12. SUGGESTEDWEBSITES
www.prb.org
www.marathon.uwc.edu
www.populationaction.org
www.uneca.org/publications/FSSD/State_of_Demographic_Transitio
n_in_Africa