Population Composition
Dr. Farrah Pervaiz
MBBS ,MSPH ,PhD Fellow
Assistant Professor
Dept of Public Health AFPGMI/NUMS

Demography
Demography is the "statistical and mathematical
study of the size, composition and spatial
distribution of human populations, and of the
changes over time, in these aspects through the
operation of the five processes of fertility,
mortality, migration, marriage and social
mobility"

Population composition
• Description of population on the basis of
characteristics such as age, race, sex or marital
status etc.
• These descriptions can be necessary for
understanding the social dynamics from historical
and comparative research.
• This data is often compared using a population
pyramid.

Classification of population Composition

Population Composition
1.AGE 2. SEX

Population Composition
3. Race
There are no standard
definitions of race and
ethnicity
4. Ethnicity/ Sub-Race
Covers racial, national,
cultural, castes or linguistic
groups.

Population Composition
5. Language
One of the most sensitive
indices of ethnic origin
because linguistic
differences tend to persist
until complete assimilation
6. Religion
Associated with a variety of
differences in attitudes,
statuses, and behavior. Of
great interest for its
hypothesized relationship
with fertility, mortality,
nuptiality, and migration

Population Composition
7.Nationality
Nationality—Country of
present citizenship, or
Country of origin
8. Marital Status
Minimum list of groups
recommended by the
United Nations
– Single (never married
– Married and not legally
separated
– Married but legally separated
– Widowed and not remarried
– Divorced and not remarried

Population Composition
9. Duration of Marriage
Age at first marriage or
number of years since first
marriage, are probably the
most useful fact for the
study of their fertility
10. Education
– School Enrollment
– School Attendance
– Literacy
And Boredom!!!

Population Composition
11.Socioeconomic Status
SES is a construct that reflects one’s
access to collectively desired
resources, be they material goods,
money, power, friendship networks,
healthcare, leisure time, or
educational opportunities
Comprises of
Income
Education
Occupation
Wealth
Social standing etc
12. Economic Participation/
Labor Force
Involves the carrying on of an
activity from which the person
derives, or attempts to derive,
pay or profit. In censuses and
surveys, the entire population
can be subdivided into the
employed and the unemployed

Population Composition
13. Occupation
Refers to the kind
of work done by
the employed
person Examples:
Teacher, sales
clerk, farmer, car
washer, etc.

Gender / Sex

Sex Ratio
Sex Ratio—Proportion of males relative to
females in a population
General formula:

Sex Ratio at Birth

Sex Ratio
• Varies from one population to another
• Desirable to consider separately the sex ratio
of important component subgroups (e.g. by
race, by ethnicity)
• Pattern by age– Higher at very young ages. In
human populations, there are more male births
than female births, with ratio generally
between 104 and 107
–Gap narrows with increasing age
–Goes below 100 by middle age

Sex Ratio of Births
Sex Ratio of Births—Number of male births per 100
female births
Ratio < 100 →
More female than male births
Ratio = 100 →
Same number of male and female births
Ratio > 100 →
More male than female births

Sex Ratio of Deaths
• Much more variable from area to area than sex
ratio at birth
• Often well above 100, i.e. males have a higher
mortality
• Important characteristics to include in further
analyses are age, race, ethnic group, residence,
marital status, and occupation

Sex Ratio of Migrants
• Shows more extreme values than sex ratio of
either birth or death
• Less uniform from area to area
• Patterns of sex-selectivity of migrants vary
depending largely on types of occupational
opportunities and on cultural factors

Source: Tabulated using data from United Nations Demographic Yearbook

Age
• Demographers’ definition of age—Completed
age, i.e. age of an individual at last birthday
• Most important variable in demographic
analyses

Age
P0-14=Proportion of children under 15
P65+ = Proportion of aged persons
P15-64 = Proportion of persons of “working age”

Age Dependency
• Dependent Population
• Active Population

Age-Dependency Ratios
Age-Dependency Ratios—Proportion of children
less than15and elderly 65+ relative to the
population of “working ages”

Child-Dependency Ratio
Child-Dependency Ratio—Proportion of children
less than 15 relative to the population of
“working ages”

Old-Age Dependency Ratio
Old-Age Dependency Ratio—Proportion of
adults over age 65 relative to the population of
“working ages”

Data Collection on Age
Data on age may be secured by– Asking a direct
question on age
– Asking a question on date of birth, or month
and year of birth
– Or a combination of these

Age-Reporting Errors
• Centenarians
Those close to 100 years tend to overestimate
their age
• Understatement
Women tend to understate their age

Age-Reporting Errors
• Overstatement
Mothers tend to round up the age of their
children
• Heaping/Digit preference
People tend to report certain ages at the expense
of others, Can occur at any digit but happens most
often with 0 and 5

Age-Reporting Errors
• Coverage—Missed or counted twice–
There is a tendency to miss the people in certain
age groups (e.g. young men)
Some people are counted twice

Method for Detecting the Extent of Age
Errors

Method for Detecting the Extent of Age
Errors…

Method for Detecting the Extent of Age
Errors -Age ratios
• In the absence of sharp changes in fertility or
mortality, significant levels of migration or other
distorting factors, the enumerated size of a
particular cohort should be approximately equal
to the average size of the immediately preceding
and following cohorts
• The age ratio for a particular cohort to the average
of the counts for the adjacent cohorts should be
approximately equal to 1 (or 100 if multiplied by a
constant of 100)
• Significant departures from this “expected” ratio
indicate either the presence of census error in the
census enumeration or of other factors

Method for Detecting the Extent of Age
Errors -Age ratios
The age ratio is then:– Compared to 100
– Plotted by single year of age
– Indices and methods have been developed to
summarize the preference of or avoidance of
particular terminal digits, e.g. Whipple’s index,
Myer’s blended method

Age Heaping
Age heaping or age preference is the
tendency for people to incorrectly report
their age or date of birth. Individuals’
heaping behaviors favor certain ages,
commonly those ending in ‘0’ or ‘5’
although there is some evidence of minor
heaping at eight

Summary indices - Whipple`s Index
• Developed to reflect preference for or avoidance of a
particular terminal digit or of each terminal digit
• The original Whipple`s index measures age heaping for
the ages ending in 0 or 5
• It assumes a linear distribution of ages in each five year
age range- linear decrease in the number of persons of
each age within the age range considered
• The choice of the range 23 to 62 is standard, but largely
arbitrary. In computing indexes of heaping, ages during
childhood and old age are often excluded because they
are more strongly affected by other types of errors of
reporting than by preference for specific terminal digits
Source: Shryock and Siegel, 1976, Methods and Materials of Demography

Whipple’s index…
• Essentially designed to detect concentration or
heaping in terminal digits 0 and 5
• Applicable when ages are reported in single years
• Designed over the range 23-62 inclusive
• Assumptions of rectangularity (ages are evenly
distributed )

Summary indices - Whipple`s Index
Ranges between 100, representing no preference for
“0” or “5” and 500, indicating that only digits “0” and
“5” were reported in the census
If heaping on terminal digits “0” and “5” is measured;

Whipple’s index…

Whipple’s index around the world
•Many of the countries that continue to havehigh Whipple’s Index values are in Sub-
Saharan Africa
United Nations Workshop on Census Data Evaluation, Hanoi, Viet Nam Data source:
Demographic Yearboo2k-6sDpeeccemiableris2s01u3eon age heaping:
http://unstats.un.org/unsd/demographic/products/dyb/dybcens.htm

Improvement in the accuracy of age
reporting over time

Summary indices – Myers` Blended Index
• It is conceptually similar to Whipple`s index, except
that the index considers preference (or avoidance) of
age ending in each of the digits 0 to 9 in deriving
overall age accuracy score
• It is based on the principle that in the absence of age
heaping, the aggregate population of each age ending
in one of the digits 0 to 9 should represent 10 % of
population
• The theoretical range of Myers` Index is from 0 to 90,
where 0 indicates no age heaping and 90 indicates the
extreme case where all recorded ages end in the same
digit

DEMOGRAPHIC PROFILE OF
PAKISTAN

https://www.worldometers.info/world-population/pakistan-population/

•The current population of Pakistan in 2023
is 240,485,658, a 1.98% increase from 2022.
•The population of Pakistan in 2022 was 235,824,862,
a 1.91% increase from 2021.
The current population density of Pakistan in 2023
is 302.08 people per square kilometer, a 1.98%
increase from 2022.

Demographic profile of Pakistan

Demographic profile of Pakistan

Demographic profile of Pakistan

• http://www.pbs.gov.pk/content/block-wise-
provisional-summary-results-6th-
population-housing-census-2017-january-03-
2018

1
What words could be used to describe the
growth of world population?
A. Exponential
B. Arithmetic
C. Logarithmic
D. Steady
E. Constant

2
How is population density calculated?
A. Area divided by population
B. Population divided by GNP
C. Resource capacity divided by population
D. Population multiplied by area
E. Population divided by area

3
What is the geographic term for a country with
a high population density?
A. A densely populated country
B. An open country
C. An overpopulated country
D. A sparsely populated country
E. An under populated country

4
The dependency ratio is the ratio of:
A. young to middle-aged people
B. young and old to working-aged people
C. old to middle-aged people
D. young to old people
E. young to working-aged people

5
Census is not affected by:
A. Seasonal migration
B. Geographical inaccessibility of areas
C. Birth and death rate of population
D. Political influence

THANK YOU!