Population Structure, Movements and Concentration

SociologySociology
Population Structure, Movements
and Concentration
By Kathy S. Stoley

Topics to be covered
Population
Population Change
 Sources of population change
Birth Rate
Death Rate
Migration Rate and its types
Population Structures
 Population Pyramids

Population
“A population is all the organisms that belong
to the same group or species and live in the
same geographical area.”

Demography
“Demography is the study of human
population.”
(Demo= population Graphy=measurement )

Top 10 populous countries of
the world

Population change
Definition :
“The difference between the size of the
population at the end and the beginning of a
period.”

First Sources of population
change
Birth rate
“The reproductive performance indicated by
the incidence of childbearing in a population
is called Birth Rate.”

Crude Birth rate
“The number of live births in a year per 1000
people in a population is called Crude Birth
rate.”
Age specific fertility rates
“The number of births to women in certain
age groups in a population.”

Second source of population
change
Mortality
“The incidence of deaths is called mortality.”
Crude death rate
“The number of deaths in a year per 1000
people in a population.”

Age specific mortality rate “
“The number of deaths per age group in a
population.”

Events that impact death rate
War
Genocide
How to reduce death rate
By improving public health
By raising economic status of an area

Third source Of Population
change
Migration
“The movement of people into and out of a
specific area.”
It includes both immigration and emigration
Immigration means the movement of
people into the area.
Emigration means the movement of people
out of an area.

Migration Rate
Migration rate
“The change per 1000 people in a population
of an area in a given year.”

Voluntary migration
“Voluntary migration is the movement of
people into a new region by their own
choice. People will migrate generally
because the new place has “pull factors”
that motivated their movement.”

Involuntary/Forced migration
“Forced migration is the movement of people
into a new region for reasons other than
their own choice. The migration is set into
motion because of “push factors” forcing
people to move.”

Mass Migration
“Mass migration is when large number of
people move at one time and it is more often
involuntary than voluntary.”

Population structure
Population pyramids depict the population
composition of a country.
Also known as “Age sex pyramids”
Because they show the population not only by
age but also by the relative proportion of
men and women in each age group.

Population growth
“An increase in the number of people that
reside in a country, state or city.”

What is Population Pyramid?
It is a diagram that gives information
about the proportion of males and
females in each age group.
Also shows:
- proportion of young people (0 -14 )
- proportion of working people (15 – 59)
- proportion of elderly people (60+)

Types of Population Pyramids
Triangular-shaped
Beehive-shaped Pyramid
 Rectangular-shaped Pyramid
Shape of pyramids is controlled by
–births,
–deaths, &
–migrations.

Triangular Shaped Pyramid
Fast Population Growth
Broad base.
Low proportion of older people.
A steady upwards narrowing shows that
more people die at each higher age band.
This type of pyramid indicates a
population in which there is a high birth
rate, a high death rate and a short life
expectancy.

Example
Nigeria
Located in Western Africa, the Federal
Republic of Nigeria (named for the Niger
River) is the most populous country of
Africa.
Annual growth rate in 2000 was 2.7%
Median age for female was 17.6 years old.

Beehive Shaped Pyramid
Slow Population Growth
Narrow Base
Large proportion of working population,
15-59 year old - large group of
economically active population
Low Birth Rates

Example
United States
Annual Growth Rate in 2000 was 0.9%
Median age for female was 36.8 years old.

Rectangular Shaped Pyramid
Declining Population Growth
Zero Pop Growth
Narrow Base
Low Birth Rates
Life-expectancy is high e.g. 80+
Low death rates

Example
Ukraine
Annual Growth Rate in 2000 was
-0.6%
Median age for female was 39 years old

T. Robert Malthus
(1766 - 1834)

Principle Of PopulationPrinciple Of Population
"Population, when unchecked, increases
at a geometrical ratio. Subsistence
increases only in an arithmetical ratio.
Slight acquaintance with numbers will
show the immensity of the first power
in
comparison with the second."

 “Population must always be kept
down to the level of the means of
subsistence.”
 “Malthus was the first to inquire
into “the means by which this level is
effected.”

 Man has no natural predators (save
for other men).
 "The passion between the sexes has
appeared in every age to be so nearly
the same, that it may always be
considered, in algebraic language as
a given quantity.“
 Population, when unchecked, will
double itself every twenty-five years.

 "...Supposing the present population
equal to a thousand million, the human
species would increase as the
numbers 1, 2, 4, 8,16, 32, 64,
128, 256, and subsistence as 1, 2,
3, 4, 5, 6, 7, 8, 9...
• "In two centuries the population would
be to the means of subsistence as 256
to 9; in three centuries as 4096 to 13,
and in two years the difference would
be almost incalculable.”

SubsistenceSubsistence
"In this supposition no limits
whatever are placed on the produce
of the earth….
“It may increase for ever, and be
greater than any assignable quantity;
yet the power of population being in
every period so much superior….

Law of Necessity:Law of Necessity:
• "The human species can only be kept
down to the level of the means of
subsistence by the constant operation
of the strong law of necessity, acting
as a check upon the greater power."

Positive ChecksPositive Checks
"The positive checks to population are
extremely various, and include every
cause whether arising from vice or
misery, which in any degree contributes
to shorten the natural duration of
human life.“
“Under this head therefore may be
enumerated all unwholesome
occupation, severe labor and exposure
to the season, extreme poverty...

• “Bad nursing of children, excesses of
all kinds, the whole train of common
diseases and epidemics, wars,
pestilence, plague and famine”.
 War
 Famine
 Disease
 Infanticide

Preventive ChecksPreventive Checks
Preventive checks aimed at reducing birth
rate by
(1) Marrying at later age
(2) Abstinence from sex outside marriage
(3) Birth Control
In Malthus’ view, birth control led to vice.
Still, he maintained, it is the least evil act
that can control population

Food and PopulationFood and Population
• This was Malthus “principle of population,”
which is basically the law of supply and
demand applied to the relationships
between food production and population
growth. As the food supply increases, food
becomes cheaper, and more children are
brought into the world. As there are more
mouths to feed, food becomes more
expensive, thus causing more land to be put
under the plow, or greater investment in
fertilizer.

The PoorThe Poor
 Consistent with his functionalist orientation,
Malthus asserts that a working class is absolutely
essential to
every society.
 Labor will always be necessary to wrest
subsistence from nature.
 The institution of private property and self-
interest provide the motivation for human thought
and action.
 It is the goad of necessity, the desire to avoid
poverty or to obtain riches that motivates much of
human industry.

Welfare ReformWelfare Reform
 This analysis of welfare does not lead
Malthus to advocate that the poor should
be left to their plight.
 Rather, he suggests some institutional
reforms--consistent with the law of
population--that will serve to make a more
just, equitable society.

Malthus’ Evolutionary
System: Eight major points
1)population level is severely limited by subsistence
2) when the means of subsistence increases,
population increases
3) population pressures stimulate increases in
productivity
4) increases in productivity stimulates further
population growth
5) since this productivity can never keep up with the
potential of population growth for long, there must
be strong checks on population to keep it in line with
carrying capacity.

• 6) it is through individual cost/benefit
decisions regarding sex, work, and
• children that population and production are
expanded or contracted.
• 7) positive checks will come into operation
as population exceeds subsistence level.
• 8) The nature of these checks will have
significant effect on the rest of the
sociocultural system--Malthus points to
misery, vice, and poverty.

CriticismCriticism
Malthus’s prediction did not come true
because
 He presented his theory in an era
marked by high population growth and
restricted farmland
He did not foresee the technological
advancements in agriculture and
contraception.

DEMOGRAPHIC
TRANSITION MODEL:
• The Demographic Transition Model
is a geographical model used to
explain the processor of change
from high birth rates and high death
rates to low birth rates and low death
rates apart of the economic
development of a country from a pre-
industrial to an industrialized
economy.

Introduction
• Demographic Transition Model (DTM)
 Represents a nation’s transition through industrialization
 Commonly involves 4 stages
 An idealized picture of population change in a country.

Criticism:
A variety of factors influence population
trend that do not fit this theory
Thus Due to advances in public health (e.g.,
sanitation, vaccines), other countries are
experiencing improved health without a
corresponding period of industrialization,
resulting in
High Birth and low death Population growth

• Population:-
A population is a summation of all the organism of
the same group or species, which live in the same
geographical area, and have the capability of interbreeding.
• Urbanization:-
Urbanization is a population shift from rural
to urban areas, and the ways in which society adapts to the
change.

Urban Area
• An urban area is a location characterized by
high human population density
vast human-built features
Urban lifestyles are generally considered more “modern” and
faster paced than non-urban lifestyles.
Rural area:-
In general, a rural area is a geographic area that is located
outside cities and towns. Rural areas are typically considered
to have a more traditional and slower-paced
lifestyle.

• Total U.S. Population and Percentage Urban, Selected
Years 1930–2000.
Sources: U.S. Census Bureau “Population: 1790 to
1990” and U.S. Census Bureau 2001a.

History of Urban Sociology
Four Largest U.S. Cities and Other Urban
Places, Selected Years 1790–2000

History of Urban Sociology
The Chicago-school sociologists produced several ethnographies of the
urban life of Chicago residents, including studies of gangs, transients,
and immigrants (Savage and Warde 1993). A 1938 piece by Louis Wirth
(1897–1952) describing an urban lifestyle has been called “one of the
most influential sociological articles ever written” (Savage and Warde
1993, 97). It is also reputed to be the article “most widely cited in
sociology” (Abercrombie, Hill, and Turner 2000, 370). In his article,
Wirth discussed differences between social interaction and life in
cities and rural areas, focusing on isolation and loss of individuality.
His argument was that cities change social relationships for the worse.
Whether this is actually the case has been examined in a variety of
subsequent studies.

Urban Ecology
Urban ecology is the scientific study
of the relation of living organisms with
each other and their surroundings in
the context of an urban environment.
Urban ecology focuses on the
interaction between human population
and the environment, including both
material and nonmaterial aspects of
human culture.

Concentric zone model
The Concentric zone model, also known as the Burgess model or the CCD model, is one of the
earliest theoretical models to explain urban social structures. It was created by sociologist Ernest
Burgess in 1923.
Sector model
The sector model, also known as the Hoyt model, is a model of urban land use proposed in 1939 by
economist Homer Hoyt. It is a modification of the concentric zone model of city development. The
benefits of the application of this model include the fact it allows for an outward progression of growth.
Multiple nuclei model
The multiple nuclei model is an economical model created by Chauncy Harris and Edward Ullman in
the 1945 article
"The Nature of Cities"

URBAN SOCIOLOGY
TODAY
First century of urban
sociology

Cont’d
Current urban
sociology

Political Economy
Perspective
Focus on the inter-
relationship between
political and economic
forces
Draws from the
conflict perspective of
“Karl Marks”

Sociospatial Model
Views local areas
as comprised of
various, often
competing, growth
networks rather
than a single
coalition.

The process of
population moving out
of central cities to
surrounding areas
Suburbs: urban areas
out of city boundaries.

Counter policies
• Urban Renewal: Government-funded
programs that aim to rejuvenate
cities.

Cont’d
• Gentrification: Affluent buy run-down
properties at low cost and upscale
them.
• Increases the property value.

Population Structure, Movements and Concentration

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