Lecture demography

‫الرحيم‬ ‫الرحمن‬ ‫هللا‬ ‫بسم‬
Demographic Concepts, Measures, and
Techniques
Presented by
Professor Dr. Md. Nazrul Islam Mondal
Department of Population Science
and Human Resource Development
University of Rajshahi
Rajshahi 6205, BANGLADESH
E-mail: nazrulupm@gmail.com

Suggested books
• Shryock, H.S. & Siegel, J.S. (1976). The Methods and Materials of
Demography. Washington DC. US Bureau of the Census.
Available at:
http://demographybook.weebly.com/uploads/2/7/2/5/27251849/david_a._swanson_jacob_s._si
egel_the_methods_and_materials_of_demography_second_edition__2004.pdf
• Manual X. Indirect Techniques for Demographic Estimation. Department of
International Economic and Social Affairs. Population Studies, No. 81.
Available at:
http://www.un.org/en/development/desa/population/publications/pdf/mortality/Ma
nual_X.pdf
• Nsowah – Nuamah, N.N.N. (2007). Demographic statistics. A Handbook of
Methods and Measures in Demography. Accra. Academic Press.
2

 Meaning and scope of Demography
 Demography is the statistical analysis of
human population data.
 It studies the population’s
i. size, i.e. number of male/female population,
ii. Distribution, i.e. rural/urban,
iii. Structure, i.e. age and sex composition,
iv. changes over time, i.e. growth or decline,
v. the causes and effects of changes.
3

Roles
i. Census: We need proper data of population
ii. Master plan of a city: To design a city, a
proper demographic data is important and
demographics play a major role
iii. Elections: During elections , demographic data
is vital
iv. Disaster management: Presently world is
facing many disaster and all these disaster
measures need a proper data and understanding
of demography.
Etc.
4

Demographers jobs
i. to calculate rates, assuming implicitly a decision-making
process regarding when, how many and how far in-
between to have babies;
ii.to explain birth intervals by postpartum amenorrhea,
voluntary abstinence, contraceptive use effectiveness,
period of infecundability and related fertility inhibiting
indicators;
iii. to construct well-designed life tables;
iv. to measure activity rates and migration rates and
periodically project the size of the total population by its
components;
v. to validate and update the results usually presented in
three variants: high, medium and low, using census figures
where available and vital registration where these exist.
5

 Population pyramid, or age pyramid, or age picture
It is a graphical illustration that shows the distribution
of various age groups in a population (typically that of a
country or region of the world), which forms the shape
of a pyramid when the population is growing.
7

Nearly half of Libya's 2011 population consists of children aged <20 years
8

Population dynamics
• Population: It is the total number of persons
inhabiting in a country, city, or any district or area.
• Population dynamics is concerned with the sizes of
populations and the factors involved in their
maintenance, decline, or expansion.
• Predicting population changes is important because
these demographic trends impact economic, social, and
environmental systems.
9

Components of population change
The main components are:
 births,
 deaths, and
 migration.
 Two ways to enter a population:
 birth, and
 in-migration
Two ways to leave a population:
 death ,and
 out-migration
10

Natural increase = births – deaths
Population change
= natural increase + net migration
Net migration
= migration inflows – migration outflows
= arrivals - departures
11

Fertility
 Fertility= The incidence of childbearing in a
country’s population.
 Fecundity= The maximum possible number of
children a woman can have in her lifetime.
 From menarche to menopause, a woman can
have more than twenty children; this total is
limited by various factors: cultural norms,
finances, environmental conditions, public
health, and personal preferences.
12

Mortality
 Mortality = The incidence of death in a
country’s population.
 Aspects of interest:
– Age at death
– Cause of death
– Life expectancy (LE)
– Healthy life expectancy (HLE)
13

 LE = The average period (years) that a person
may expect to live.
 LE at birth= Average number of years a baby
born this year can expect to live, if current
age-specific death rates remain the same.
It is a good indicator of health conditions.
 HLE= The health status data to estimate
expected years of life in good health for
persons at a given age.
14

Migration
 Migration = the movement of people into or
out of a specified territory.
-Refers to movement across a territorial
boundary for the purpose of changing
one’s usual place of residence.
 Immigration = movement into a territory
 Emigration = movement out of a territory
15

 International migration = Crossing a national
border to change residence.
 Internal migration = Movement within a country.
-This refers to movement across a county
line to change residence.
-Urbanization is a common consequence of
internal migration (rural–urban) in many areas.
16

Measures of migration
 In-migration rate = the number of people moving
into a specified territory per 1,000 people.
 Out-migration rate = the number of people moving
out of a specified territory per 1,000 people.
 Net migration = the difference between the
number of people moving into a territory and the
number moving out of the same territory in a given
time frame (usually one year).
17

Balancing equation for population
Let, Pt = population at time t
Pt+n = population at time (t+n)
n = length of time interval in years
B = number of births
D = number of deaths
NI = natural increase=B-D
Min = in-migration (from the rest of the country to a region)
Mout = out-migration (from a region to the rest of the country)
I = immigration (from other countries to a country)
E = emigration (from a country to others)
NM = net migration = balance of migration inflows and migration
outflows
Δ = change
19

Population change
=natural increase + net migration
Δ = Pt+n – Pt = NI + NM
Population accounting equation:
Pt+n = Pt + NI + NM
= Pt + (B – D) + (Min – Mout) + (I – E)
20

 Demographic intensity/strength/amount
measures
 Ratio: the relative size of one number to another.
 Rate: the ratio of number of demographic events to
the population at risk experiencing the event.
 Proportion: a ratio of the numerator to the
denominator
 Probability: the ratio of the number of demographic
events to the initial population at risk.
 Re-scaled rates or probabilities: proportions and
rates are rescaled depending on purpose and
intensity level,
e.g. percentages = proportion  100
e.g. rates per 1,000 = proportion  1000
21

 Populations at risk
 The population at risk is the population that is
exposed to the occurrence of a vital event.
 Examples: The total population in the case of
deaths, the legally married population in the case
of divorces and so on.
22

 Basic measures of population change
23
1000
years19-10agedpopulationfemale
years19-10agedfemalestoabortionsofnumber
rateabortionTeenage5.
1000
abortionsofnumber
rateAbortion4.
1000
years19-10agedfemalestobirthsofnumber
ratebirthage-Teen3.
1000
groupagein thatpopulationfemale
groupagespecificainfemalestobirthsliveofnumber
ASrate,birthspecific-Age2.
1000
populationtotal
birthsofnumber
rate,birthCrude1.





BR
CBR

• Basic measures of population change
(Continued….)
24
)years49-10agedfemaleforratesbirthspecific-ageyear-(five5
TFRrate,fertilityTotal10.
1000
years19-10agedforspregnancieestimated
ratepregnacyTeenage9.
1000
spregnancieestimated
ratePregnacy8.
lossesfetaltotalestimatedabortionsofnumberbirthsofnumber
spregnancieEstimated7.
abortionsof10%birthsof20%lossesfetaltotalEstimated6.






25
1000
populationtotal
deathsofnumber
CDRrate,deathCrude15.
1000
birthsofnumber
ageofyearonebeforebutlifeofdays27firstthe
afteroccuringinfantsbornlivetodeathsofnumber
ratemortalityalPostneonat14.
1000
birthsofnumber
lifeofdays27firstewithin thoccuringinfantsbornlivetodeathsofnumber
ratemortalityNeonatal13.
1000
birthsofnumber
ageofyear1underinfantsbornlivetodeathsofnumber
IMRrate,mortalityInfant.12
100
birthsofnumber
grams2500thanlesshtbirth weigawithbirthsofnumber
birthsweightlowPercent.11





 Basic measures of change (continued)

• Basic measures of change (continued)
26
1000
periodsamein theyears49-15agedwomenofnumber
periodstatedainbirthsofnumber
GFRrate,fertilityGeneral.20
1000
populationtotal
annulmentsanddivorcesofnumber
rateDivorce19.
1000
populationtotal
marriagesofnumber
rateMarriage.18
1000
groupagefor thatpopulation
groupagespecificafordeathsofnumber
ASDRrate,deathspecific-Age.17
1000
populationtotal
causespecificafordeathsofnumber
ratedeathspecific-Cause.16






27
 Basic measures of change (continued)
1000
years49-15agedwomenofnumber
years5underchildrenofnumber
CWRratio,wmen-Child.25
femalesofnumber
malesofnumber
ratioSex.24
100
populationworkingofnumber
elderlyandchildrenofnumber
ratioDependency.23
birthstotalofnumber
birthsfemaleofnumber
TFRrateonreproductiGross22.
1000
years49-15agedwomenofnumber
years5agedunderchildrenofnumber
CWRratio,womenChild.21






Demographic stages
Pre-industrial Stage
i. Birth and death rates high
ii. Modest population growth
Transitional Stage
i. Lowered death rate
ii. Rapid population growth
Industrial Stage
i. Birth rate decline
ii. Population growth slow
Post Industrial Stage
i. Low birth and death rates
ii. Population growth very slow
28

 Old Balance: (High fertility & High Mortality)
A large supply of births was necessary to compensate for the
large number of deaths. MMR & IMR extremely high
 New Balance: (Low fertility & Low Mortality)
Represents an improved condition of human efficiency & health,
with fewer deaths considerably less efforts required to bring a
generation to maturity. Production of agricultural & industrial
commodities is greater & life style is more comfortable
 Imbalance: (High Fertility & Low Mortality)
In between old & new balance is the period of rapid natural
increase. This growth is helpful for under-populated nations. Too
fast growth of population leading economic, social & political
chaos ( being faced by numerous developing countries including
Pakistan)

Europe, Japan & USAZero or very slowLowLow
Europe 19th century, East Asian
countries in the mid 20th century
SlowLowDeclining
Europe 18th century, Pakistan
1970s
RapidLowHigh
Europe 17th century, India
1930s – 40s
SlowDecliningHigh
Europe prior to 15th
century, most other
developing countries till
the 19th century
Zero to very slowHighHigh
ExampleNatural
Increase
Death RatesBirth Rates

• The widespread population growth is viewed as the
greatest obstacle to the economic and social
development of the majority of peoples in the
underdeveloped world.
• Approximately 95% of population growth is in developing
countries.
• Currently, 1/3 of the world population is < 15 years, and
will soon enter the reproductive bracket, giving more
potential for population growth.

World Population Trend/Population Dynamics:
2000 years ago 250 million population
1800 978 million
1900 1650 million
1950 2.5 billion
1970 3.6 billion
1980 4.4 billion
1985 4.8 billion
2000 6 billion
2016 7.4 billion

Rank Country Highest TFR Country
Lowest TFR
1 Niger 7.6 Korea, South 1.2
2 South Sudan 6.7 Romania 1.2
3 Congo Dem. Rep 6.5 Singapore 1.2
4 Chad 6.4 Taiwan 1.2
5 Somalia 6.4 Bosnia-Herzegovina 1.3
6 Burundi 6.1 Greece 1.3
7 Angola 6.0 Moldova 1.3
8 Mali 6.0 Poland 1.3
9 Mozambique 5.9 Portugal 1.3
10 Uganda 5.8 Spain 1.3
35
Top 10 countries with the highest and lowest TFR, 2016

Rank Country
2015 population
(in millions)
Country
2050 population
(in millions)
1 China 1376 India 1705
2 India 1311 China 1348
3 USA 322 Nigeria 399
4 Indonesia 258 USA 389
5 Brazil 20b Indonesia 321
6 Pakistan 189 Pakistan 310
7 Nigeria 182 Brazil 238
8 Bangladesh 161 Bangladesh 202
9
Russian
Federation
143
Dem. Rep. of
the Congo
195
10 Mexico 127 Ethiopia 188
36
Top 10 countries with the largest populations, 2015-2050

• Economic and environmental implications
Due to population explosion there are
– Short term pressure affects during 2-3 decades
– Long term over next century and beyond economic
affects
• Demographic, social, political implications
In population with low birth and death rate, 20-30% of
population is under 15; 9-13% is 65 or more. The median
age for this population is 32 and there is increased demand
for senior citizen

Rank Country Population density (Number of people/km2)
1 Macau 20,848.01
2 Monaco 15,254
3 Singapore 7,987.52
4 Hong Kong 6,442.65
5 Gaza Strip 5,045.5
6 Gibraltar 4,490
7 Holy See (Vietnam City) 1,913.64
8 Bahrain 1,729.06
9 Maldives 1,320.79
10 Malta 1,305.87
39
Top 10 densely populated countries

40
Effects of overpopulation
• Ultimate shortages of energy sources and other natural resources,
• Famine
(A famine is a widespread scarcity of food, caused by several factors including crop failure,
population imbalance, or government policies).
• Serious communicable diseases in dense populations
• Shortage of arable land (suitable for growing crops)
• Little surplus food
• Mass extinctions of plants and animals as habitat is used for farming and
human settlements
• War over scarce (insufficient for the demand) resources such as land area.

41
Effects of overpopulation (continued)
• High birth rates
• Lower life expectancies
• Lower levels of literacy
• Child poverty
• Higher rates of unemployment, especially in urban
• Poor diet with ill health and diet-deficiency diseases (e.g. rickets)
• Low per capita GDP
• Increasingly unhygienic conditions
• Government stretched economically
• Increased crime rates resulting from people stealing resources to
survive

Top ten highest IMR countries, 2015
1 Afghanistan 112.80
2 Mali 100.00
3 Somalia 96.60
4 Central African Republic 88.40
5 Guinea-Bissau 87.50
6 Chad 87.00
7 Niger 82.80
8 Angola 76.50
9 Burkina Faso 73.80
10 Nigeria 71.20
45

Population clock, 2016
World More developed
countries
Less developed
countries
Population 7,418,151,841 1,254,309,821 6,163,84,2020
Births per Year 147,183,065 13,714,857 133,468,215
Day 403,241 37,575 365,666
Minute 280 26 254
Death per Year 57,387,752 12,580,616 44,807,108
Day 157,227 34,467 122,759
Minute 109 24 85
Natural
increase
Year 89,795,313 1,134,242 88,661,107
Day 246,015 3,108 242,907
Minute 171 2 169
Infant
deaths per
Year 5,226,233 65,229 5,160,998
Day 14,318 179 14,140 47

World population highlights
2.8 million
Metric tons of carbon
emitted by China in 2013,
almost four times the level
of 1992
50%
Percentage of the
population in Niger that is
less 15 years old
$1,760
GNI per capita of Haiti
54%
Percentage of the world’s
population living in urban
areas
4.9
Average TFR in Eastern
African countries
729 million
Projected population of
Europe, down from 740 in
2016
38
Infant deaths per 1000 live
births in Bangladesh
34%
Percentage of people in the
lest-developed countries
with access to electricity,
compared to 85% globally
8.3 years
Suffering from disability,
since global LE (71.4 years)
and HLE (63.1 years)
48

Lecture demography

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