Chapter 2: Population

Chapter 2: Population
Tracy Otieno
Dedeepya Mulpuru
What is Population?
• Population
– The number of people in
a given region
– Counted by a census
which is counted every
10 years in most
• Census
– The counting the
population in a region.
– Gathers information
including gender, race,
age, income..etc.
• Demography
– The study of
characteristics of
human population
• Population Density
– Number of people
occupying an area of
U.S and World Population Clock
Measuring population
• 2/3rds of the world
population is
concentrated in four
specific areas:
– East Asia, Southwest
Asia, South Asia and
• Ecumene
– Portion of Earth’s
surface occupied by
permanent human
• Crude density
– Number of people in a
given area
• Population Density
– Total number of people
divided by total land area
• Agricultural density
– Number of farmers per
arable land
• Physiological density
– Number of people per
arable land
Population Change
• Total Fertility Rate
– Average number of
children a woman will
have during childbearing
• Infant Mortality Rate
– Number of infants under
age 1 compared with
total live births
• Life Expectancy
– Average number of years
expected to live
• Crude Birth Rate
– Number of births per 1,000
• Crude Death Rate
– Number of deaths per 1,000
• Doubling time
– Amount of time it takes the
population to double of a
given region
• Natural Rate of Increase
– Percentage of population
growth in a year
– Equation: (CBR-CDR)/10
Population Pyramid
• A bar graph that displays age
and gender of a population.
– The shape is determined by
the CBR
– Influenced by % of population
in each age group and
distribution of males and
• Sex ratio
– Number of males per 100
• Dependency ratio
– Number of people to young or
too old compared to those
who work
Why does population increase at
different rates in different places?
• Based on the demographic transition model,
it explains population change as a country
develops from a pre-Industrial to an
industrialized economic system.
Stage 1:
Stage 2:
Stage 3:
Stage 4:
Epidemiologic Transition Model
• Focuses on the distinctive causes of death in each stage of
the demographic transition:
– Stage 1: Pestilence and famine
• Black Plague
– Stage 2: Receding Plague
• Affects high percent of population and is wide spread
• cholera
– Stage 3: Degenerative and human-created diseases
• Decline of infectious diseases and is associated with aging
• cancer
– Stage 4: Delayed degenerative diseases
– (Stage 5: Reemergence of infectious diseases and parasitic
• Evolved diseases, new strains.
• Malaria
Malthus Theory
• Wrote an essay
Principle of Population
of 1798 which stated
that the population
would growing too fast
for the food supply.
– Critic:
• Failed to considered
population growth in
poor countries which
would result with a
wider resource gap.
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