Session 1 introduction of demography (as of 3-1-2017)

1. Introduction to Demography
Dr. Min Ko Ko
M.B.,B.S, M.Med.Sc. (Public Health)
Ph.D. in Demography (Mahidol University)
Associate Professor
Health Behaviour & Communication Department
University of Public Health

2. Ground Rules for today discussion?
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3. Outline of Presentation
I. Meaning and Scope of Demography?
II. Origin of Demography
III. Sources of Demographic measures
IV. Uses of Demography
V. Basic Measurement of Demography

4. What is Demography?
• Demography is the statistical study of (human)
populations.
• It includes the study of:
Size,
Structure,
Distributions and
Changes over time.
By 3 Components:
 Birth (Fertility)
 Death (Mortality)
 People move in & out (Migration)
Analytical Demography
(or) Formal Demography
I. Meaning and Scope of demography?

5. Scopes of Demographic Analysis
•Size :
–number of units (persons) in the population.
•Structure :
–the distribution of the population among its Age & Sex
groupings. (Population Pyramid)
•Distribution :
–the arrangement of the population in space/geographical
area at a given time.
•Change :
–the growth or decline of the total population or of one of its
structural units.

6. Components of Change
• There are only 3 components of change in the population:
1) Births (B) (Fertility)  increasing of pop.
2) Deaths (D) (Mortality)  decreasing of pop.
3) Migration
•In-migration (IM)  increasing of pop.
•Out-migration (OM)  decreasing of pop.
P2 = P1 + (B – D) + (IM – OM)  ‘Balancing Equation

7. What is Demography? (cont:)
• Determinants Factors
• It also includes the analysis of the relationships between
economic,
social,
cultural, and
biological process
--------
--------
---------
Substantive Demography
Demography?
Analytical Demography + Substantive Demography
influencing a population changes
(Fertility, Mortality, Migration)

8. II. Origin of Demography
• John Graunt (1620-1674)
• -He is called father of demography because his book Natural
and Political Observations Made upon the Bills of Mortality,
published in1662
Bills of Mortality means ‘lists of the
dead’ by plague disease.
-Weekly statistics on burials of plague
-Main idea is to monitor the
geographical incidence of deaths from
plague.

9. Origin of Demography (cont:)
• John Graunt’s Observation
• Vital Events
• Gender Differences:
More male were born between 1628 and 1662.
More Males were died earlier than females by Plague
• Life Table:
• Public Health:
• Epidemiology- Plague: germs were carried by fleas
that lived as parasites on rats
The scientific study of demography began with the study of
mortality.

10. III. Sources of demographic measures
1) Vital Registration
2) Survey
3) Census

11. Vital Registration Survey Census
Data collected in
continuous basic
Limitation:
oQuality of Data
oData Accuracy
oAge misreporting
oUnder reporting
 Birth
 Death
 Child Death
 Adult Death
 Maternal D
Data collected in
fixed point in time
Cheaper
Representative
Population
Short duration
More information
from prepared Q:
Limitation:
Nationally
Representative
Sampling error
Data collected in
fixed point in time
Nationally
Representative, cover
whole population
Limitation:
Very Expensive
Longer duration
Limited
information
because of
Questionnaires

12. VR in Myanmar
• -first introduced to some parts of lower Myanmar in 1907;
and then gradually extended to other parts of the country.
• Incomplete during British colonial periods.
• Interrupted during World War II and Japanese invading to
Myanmar, and didn’t resume until 1947.
• Postwar VRS are also limited to data accuracy.
• The present VRS were introduced in Myanmar in 1962 in the
urban areas. The data is collected by Department of Health,
Ministry of Health & Sports and compiled and published by
Central Statistics Organization (CSO).
• Since 2007, VRS covers the entire population of the Myanmar

13. Surveys
• Eg:
Demographic Health Survey (DHS)
World Fertility Surveys
Multiple Indicators Cluster Survey (MICS)
Fertility and Reproductive Health Surveys

14. Surveys in Myanmar
• Fertility Surveys
Population Changes and Fertility Survey” (PCFS)-
1991
Fertility and Reproductive Health Surveys’ (FRHS
surveys)- 1997, 2001 & 2007
• Mortality Surveys
Overall and cause specific under five mortality survey 2002-2003
Research Study on The Determinants of Infant and Child Morbidity
and Mortality in Myanmar 2005
• Migration Surveys
• Elderly Surveys
Elderly surveys 2005 and 2012

15. Census
• Census is the main sources of demographic data.
• A census is defined as the total process of collecting, compiling
and publishing demographic, socioeconomic data pertaining, at
a specific time or times, to all persons in a country or delimited
territory.
• Two types of census.
1) Dejure census - counts the persons according to their usual
place of residence
2) Defacto census - counts the persons where they are found
on census day.
• Both methods have some advantages and disadvantages.
1) In Dejure census, there is problem of definition of “usual
residence” because some have more residence place and
some have no residence.
2) In Defacto, there is problem of counting person who
travelling on census day or who works at night.

16. Census in Myanmar
• History of census was initiated by the era of ‘King Thadodipa
Mahadamayaza of the Tagaung Dynasty’ to know the actual population of
his country.
• The first Myanmar population census was taken in 1872 under the
British administration covering the lower part of Myanmar; as one part
of the Indian census.
• The second one was in 1881.
• Thereafter, censuses were taken every ten years since 1881till 1941; but
they did not cover the entire country.
• After independence in 1948, the first nationwide population census was
taken in 1973 and followed by 1983.
• The last census was performed in 2014 March/April and enumerated a
total population of 51.8 millions.
• Ministry of Immigration and Population is a focal Ministry to conduct
nation-wide censuses.

17. • Other Data Sources in Myanmar
• Department of Health Planning- makes available health statistics
through its publication
Health Management Information System (HMIS)
Multiple Indicators Cluster Surveys (MICS)
District Health Information System (DHIS)
• Ministry of National Planning and Economic Development
Central Statistical Organization- Publishes “Statistical
Yearbooks”

18. IV. Uses of Demography
• Definitions
• Populations:
Size -
Structure (Age structure, Sex structure) -
Distributions (Geographical distribution)-
Changes over time (Growth/Decline)
By 3 Components:
Birth (Fertility)
Death (Mortality)
 People move in & out (Migration)

19. • Demography is widely used for various purposes and can
encompass small, targeted populations or mass populations.
• Nation’s SE development-Eg: Life Expectancy at birth
• SE & Living Conditions
• For Governments:
Political observation
• Decision Making- It provide to determine the adequate policies
and plans related to population, economic, social and
environment issue both at the country level and locality level.
• Policy & Planning to provide public utilities and services to the
needs of people in each area
IV. Uses of Demography (cont:)

20. • For Scientists: use demography for research purposes,
• For Public and Private-
Business Decision
• Population Projection
• Fertility-
• Mortality--
• Migration Migration & Health
• Other Fields -
IV. Uses of Demography (cont:)

21. • Why Study Demography?
An understanding of population dynamics:
 ◦Helps explain social phenomena
 ◦Helps identify social needs
 ◦Helps plan for future needs
 What dynamics are important?
 ◦Age structure
 ◦Mortality & illness
 ◦Fertility & birth patterns
 ◦Marriage and family formation
 ◦Migration and population movement
 ◦Population growth, competition for resources
 Demography is the bridge from the micro to macro level

22. • Break! x 10 minutes

23. Measurements Used in Demographic Analysis
•Basic measurements: simple statistical measurements
•Fertility measurements
•Mortality measurements
•Migration measurements

24. Basic Measurements
• Simple statistical measurements:
Ratio
Proportion
Percentage
Rate
Probability

25. Basic Measurements: Ratio
• The ratio of X to Y
X
Y
•Examples of ratios:
Sex ratio: number of males per 100 females
Q: Sex ratio of today class?
Ratio is a single number that expresses the relative size of two
numbers.
The result of dividing a number of X by another number Y is the
ratio of X to Y.
Numerator is not included in the denominator.

26. Exercises
• In Myanmar, As of 2014 Census,
• Male = 24225304
• Female= 25987763
• Sex Ratio= ??
SR of Myanmar= 93 Males for every 100 females

27. Basic Measurements : Proportion and Percentage
• Proportion:
X
(X+Y)
• e.g. The proportion of
the population under
age 18 is .65
•Percentage:
X
(X+Y)
e.g. The percentage of the
population under age 18 is 65%
x 100
Q: Male Proportion of today class?
Q: Male percentage of today class?

28. Basic Measurements : Rate
Rate = Number of events
Population at risk
Rate = Number of events
Person-years lived
Rate = Number of events
Mid-year population
x 1000
x 1000
x 1000
A rate is the occurrence of events over a given interval in time. Rate
is used to study the dynamics of change.
Rate of incidence= #of events that occur within a given time
interval/# of members of pop: who were exposed to the risk of the
event during the same time interval.

29. Examples of Rates
•Crude birth rate (CBR):
Number of births in a year
Mid-year population
• Crude death rate (CDR):
Number of death in a year
Mid-year population
x 1000
x 1000

30. Population at Risk Person-Years Lived Mid-Year Population
PAR is real
denominator for
rate.
But, it is difficult to
get the PAR.
For the reasons,
PYL are used
instead of PAR in
denominator
The concept of PYL is ideal way
to specify the PAR of an event.
It is simply the product of the
number of persons multiplied
by the number of years, that
each person lived in a given
place.
PYL = no. of person x no. of year
But, the calculation of actual
PYL of any Larger Size would be
difficult, it is not impossible.
For the reasons, MYP are used
instead of PYL in denominator
If we assume that births,
deaths, and movements in
and out of the population
are evenly distributed
throughout the year, the
number of people alive at
the middle of the year
(July 1) would equal the
number of PYL.
This population alive at
the middle of the year is
called MYP.
So, MYP is usually a good
approximation of PYL.
Note: (if B,D,M are not
evenly distributed, we
cannot apply as MYP =

31. Calculating Mid-Year Population
•Mid-year population
= (P1 + P2) / 2
= [P1 + (P1 – D)] / 2
= P1 - ½ D
= P1 – ½ (P2 – P1)
• where:
• P1 = population on 1st January
• P2 = population on 1st January next year
• D = Deaths in a year
Q: Which formula is easy to memorize?

32. Basic Measurements : Probability
Number of events
Population at the beginning
•Ranges between 0 and 1
•Measured during a fixed period
• e.g. Probability of dying at age 25:
Number of deaths at age 25
Number of people who reach age 2
Probability is similar to a rate, with one important difference.
The denominator is composed of all those persons in the given pop:
at the beginning of the period of observation

33. What you learned today?
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34. More Readings
• PALMORE, J. A. & ROBERT W. GARDNER. 1983. Measuring
Mortality, Fertility, and Natural Increase: A Self- Teaching
Guide to Elementary Measures. Honolulu: The East-West
Center. Chapter I (p.1-7)
• ROWLAND, D.. 2003. Demographic Methods and Concepts.
Oxford : Oxford University Press. Chapter I (p.13-44)