Demography is the scientific study of human populations. Key events in the history of demography include Ibn Khaldun's work in the 14th century, John Graunt producing the first life table in the 17th century, and John Snow mapping cholera deaths in London in the 19th century. Major population theories include Malthus' theory of unchecked population growth outstripping resources, Marx's view that population is controlled by economic factors, and the demographic transition theory of declining birth and death rates as countries develop. India's current population is over 1.2 billion with a growth rate of 17.6% in the last decade. Key demographic indicators of India include sex ratio, age composition, and dependency ratio.

1. DEMOGRAPHY
1
Dr. Vineetha K.
Department of public health dentistry
BASIC PRINCIPLES

2. CONTENTS
01
02
03
05
04
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POPULATION GROWTH
CAUSES OF POPULATION GROWTH
FUNCTIONS OF DEMOGRAPHY
INTRODUCTION
IBN KHALDUN
JOHN GRAUNT
EDMUND HALLEY
JOHN SNOW
HISTORY
MALTHUSIAN
MARXIAN
OPTIMUM POPULATION
DEMOGRAPHIC TRANSITION
THEORIES
DEMOGRAPHIC
PROCESSES
CYCLE
MODEL
INDIA IN NUMBERS
-POPULATION STATISTICS
-VITAL STATISTICS
DEMOGRAPHIC
INDICATORS
POPULATION
TRENDS
2

3. TIMELINE
• Few million years ago 10 MILLION
• 8000 BC 500 MILLION
• 1800 1 BILLION
• 1930 2 BILLION
• 1975 4 BILLION
• 1999 6 BILLION
• 2011 7 BILLION
FUTURE POPULATION PROJECTION
• 2030 9.5 BILLION
• 2100 12.6 BILLION
Population growth – an epidemic of homo sapiens
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Population Reference Beaureu
INTRODUCTION

4. CAUSAL LOOP DIAGRAM
4

5. DEMOGRAPHY
Demos – People Graphy - Measurement
Scientific study of human population
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6. FUNCTIONS OF DEMOGRAPHY
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7. HISTORY
IBN KHALDUN (1332-1406)
• Father of demography
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Economic analysis of social organization which produce the
first scientific and theoretical work on population,
development and group dynamics

8. JOHN GRAUNT
Credited for producing the first life table,
giving probabilities of survival to each age.
8

9. EDMUND HAILLEY
• Halley developed life table based on sound
demographic data and discussed several
applications of his life table including
calculations of life contingencies.
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10. LONDON CHOLERA MAP - JOHN SNOW
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He plotted every death
on a map with
Ingenious mapped bar
charts and was able to
show that The closer to
the broad street the
water pump he plotted,
the greater the no of
deaths
This information helped
convince the public a
true sewage system
was needed and spurred
the city into action

11. THEORIES OF POPULATION
GROWTH AND DECLINE
• Malthusian theory
• Marxian theory
• Optimum population theory
• The demographic transition theory
11

12. MALTHUSIAN THEORY
• Thomas malthus (1766-1834) thoerized pessimistically that
population was uncontrollable
• Population when unchecked, increases in a
geometrical ratio (exponentially) Substinence
increases only in an arithmetic ratio (linearly) 12
Overpopulation and Massive Poverty

13. MARXIAN THEORY
• KARL MARX believed that the problem was not
primarily one of the population but one of the
ownership of the means of production and the
inequitable distribution of the societies wealth.
• Marx felt that population could ultimately be controlled
by the complex workings of market economics and that
the economic markets, as they expanded, would be able
to sustain population at whatever level it had reached.13

14. OPTIMUM POPULATION THEORY
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Population must grow up to certain desired level after which
further growth is harmful.
By CANAN

15. DEMOGRAPHIC TRANSITION
THEORY
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1. High birth rate and high death rate
2. High birth rate and low death rate (population
explosion)
3. Low birth rate and low death rate
Industrial and commercial development first cuts the
death rate but creates a desire for smaller families and
eventually cuts the birth rate.
-Proposed by F. Notestein

16. 16
To describe population dynamics is the
Demographic Transition Cycle and Model.
o First stage - High stationary
o Second stage - Early expanding
o Third stage - Late expanding
o Fourth stage - Low stationary
o Fifth stage - Declining
HIGH
STATIONARY
EARLY
EXPANDING
LATE
EXPANDING
LOW
STATIONARY
DECLINING
by C.P Blacker

17. DEMOGRAPHIC CYCLE
5 STAGES OF DEMOGRAPHI CYCLE
STAGE BR DR EXAMPLES
Stage HIGH India was in this
1 STATIONARY stage till 1920
Stage EARLY South Asia & Africa
2 EXPANDING
Stage LATE India, China
3 EXPANDING Singapore
Stage LOW UK, Denmark, Sweden
4 STATIONARY Belgium
Stage DECLINING Germany & Hungary
5
17
INDIA 1920 High stationary
INDIA PRESENT Late expanding

18. DEMOGRAPHIC TRANSITION MODEL
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The model of demographic transition suggested that a population's
mortality and fertility would decline as a result of social and economic
development. It predicted that all countries would over time go through
four demographic transition stages.

19. POPULATION MOMENTUM
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Population growth at the national level that would
occur even if levels of childbearing immediately declined
to replacement level.
CAUSE – due to weighting of age structure towards the young
Once the older generation dies, the population will start shrinking

20. DEMOGRAPHIC PROCESSES :
Demographic
Process
Fertility
Mortality
Marriage
Social
Mobility
Migration
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21. DEMOGRAPHIC INDICATORS
POPULATION SIZE
POPULATION DENSITY
SEX RATIO
DEPENDENCY RATIO
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BIRTH RATE
DEATH RATE
GROWTH RATE
LIFE EXPECTANCY AT BIRTH
MORTALITY AND FERTILITY RATE
POPULATION
STATISTICS
VITAL
STATISTICS

22. INDIA IN NUMBERS
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23. POPULATION SIZE
• India’s current population – 1.21 billion
• The growth rate of population for India in the
last decade – 17.64%
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24. POPULATION DENSITY
• Occupies 2.4% of the world surface area
• It supports 17.5% of worlds population
• Density - 382 per square km
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25. SEX RATIO
Number of females per 1000 males in the population
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CAUSES OF LOW SEX RATIO
• Strong male child preference
• Consequent gender inequalities
• Neglect of girl child
• Female infenticide
• Female foeticide
• High MMR
• Male bias in population enumeration

26. AGE COMPOSITION
• Proportion of population < 14 yrs. – “DECLINING TREND”
• Proportion of the elderly “INCREASING”
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POPULATION PYRAMID
Represents age structure of a population
A type of double sided bar graph
- % of population Males Vs. Females on opposite sides
- Shape of graph correlates with rate of population growth

27. INTERPRETING POPULATION PYRAMID
• Developing countries = rapid growth = more
young than old
• Developed countries = slow growth = about
equal numbers of all age groups
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28. 28
ACCORDING TO DEMOGRAPHIC TRANSITION STAGES
• Most developed countries have completed the
demographic transition and have low birth rates;
• Most developing countries are in the process of this
transition.[

29. FERTILITY
• Total number of children borne by a women at a point
of time during her child bearing age (15 to 45 years)
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• Total fertility rate(TFR) gives an idea of total family size
• TFR in India: 2.68 (NFHS -3)
Family size depends upon
Duration of marriage
Education of couple
No of live births
Contraception method
Socio economic status
“2 CHILD FAMILY NORM :
LONG TERM GOAL NRR=1

30. MORTALITY
Refers to the number of deaths.
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MATERNAL MORTALITY RATE INFANT MORTALITY RATE
(maternal deaths per 1,00,000 live births)
INDIA 2007 to 09 - 212
2011 to 12 - 178
CAUSES
 Haemorrhage
 Infection(sepsis)
 Eclampsia
 Obstructed Labour

31. LIFE EXPECTANCY
• Expectation of life – at a given age is the average number of
years which a person of that age may expect to live, according
to the mortality pattern prevalent in that country
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Indicator of country’s level of development & overall health status of the population
Expectation of life
at birth – world
1950 : 46.5 years
2002 :63 years
Census 2011 : the value of life expectancy at birth in India- 65.48 as of 2011

32. DEPENDENCY RATIO
FOR THE YEAR 2010 :
• Young age dependency ratio -47.9%
• Old age dependency ratio - 7.7%
DEMOGRAPHIC BURDEN
• Increase TDR
• Cause of economic burden
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Total Dependency Ratio = 0-14 Years + 65 Years And Above
15 To 65 Years

33. LITERACY AND EDUCATION
A person (7 yrs or more) is considered as literate if he or she
can read & write with understanding in any language.
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Highest literacy rate in India – KERALA (93.91)
Low for – Bihar (63.82)

34. MIGRATION
IMMIGRATION
Happens when one
enters the country of
destination but not
permanently.
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Migration affects population patterns.
EMIGRATION
Happens when one
leaves ones’s country
in order to move into
another permanently.

35. URBANIZATION
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CENSUS 2011 Rural Population
(million)
Urban Population
(million)
Increase in Urban
Population (%)
INDIA 833.1 377.1 3.35
CAUSES OF URBANIZATION:
MIGRATION
• Better employment opportunities
• Better living standards
• Better availability of social services like Education,
Health, Transport, Entertainment etc
INTERNAL MIGRATION
Within the country
Rural Urban
URBANIZATION

36. DEMOGRAPHIC DATA
• Demographic Data or Demographics are the
quantifiable statistics of a given population.
SOURCES
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Census
Vital Registration Statistics System Sample or special Surveys
Demographic data Gathered and
Processed by Government Agencies

37. • China is the most populated country with approximately
1.39 billion people in 2014.
• India’s population will reach 1.53 billion by 2050 and
will be the highest in world
37
CAUSE - Higher population growth of india 1.2 %
compared to 5% of china.
POPULATION EXPLOSION

38. CAUSES OF OVERPOPULATION IN INDIA
Birth rate The Fertility Rate
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39. IS POPULATION GROWTH A BLESSING
OR A CURSE?

40. BLESSING
• Better economy
• Efficient utilization of resources
• Medical, agricultural and industrial growth
• Better Labour Force
• Greater Investments and Capital Formation
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41. CURSE
• Shortage of Food and land
• Environmental Problems
• Problem of Unemployment
• Poverty and Low Standard of Living
• Inflation
• Conflict and war
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42. National Population Policy -2000,
India aims at
SHORT TERM: Fullfill unmet need for contraception,
strengthening the health infrastructure, integrating
the services for Reproductive and Child Health.
MEDIUM TERM: Effective implementation of inter
sector strategies to substantially reduce the TFR by
2010.
LONG TERM : To sustain the economic growth,
social development and eco- conservation, stabilise
the population by 2045.
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43. CONCLUSION
• Health status of a community depends upon
the dynamic relationship between the number
of people, their composition and distribution.
• Planning of health services can be guided by
demographic variables.
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44. REFERENCES
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1. 2011 Census Of India
2. Population Reference Bureau, 2005 World
Population Data Sheet
3. K. Park, Park’s Textbook of Preventive
&Social Medicine ,21st Edition
4. MC Gupta & BK Mahajan,Text Book of
Preventive & Social Medicine,3rd Edition
5. Soben Peter, Essentials of Preventive
&Community Dentistry, 4th Edition

45. Thank You!
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