Demography—The study of a population in its
static and dynamic aspects.
Static aspects: include characteristics at a point
in time such as composition by:
– Age –
Sex – Race – Marital status – Economic characteristics
Dynamic
aspects are: – Fertility – Mortality – Nuptiality – Migration – Growth
Demographic Analysis—The study of components of variation
and change in demographic variables and the relationships between them. This is also called formal demography or
demographic methods
Population
Studies : The study of
the relationships between demographic variables and other variables such as
social and economic variables.
Civil Registration:
History: – Relatively modern concept in its
present format
– Churches have long maintained
baptism and burial registries
– Provided insight on the
demographic situation since the late Middle Ages
Purpose : -- Primarily administrative
– To collect data on the
vital events happening in a population (generally concerned with live births,
deaths, marriages and divorces)
–
Help
understand demographic characteristics of different populations at different
points in time
Essential characteristics: – Universality –
Continuity
Definitions and content
– Live birth – Death
– Marriage – Divorce
Live
Birth :
—Complete
expulsion or extraction from its mother of a product of conception,
irrespective of the duration of pregnancy, which after such separation,
breathes or shows any other evidence of life such as beating of the heart,
pulsation of the umbilical cord, or definite movement of voluntary muscles,
whether or not the umbilical cord has been cut or the placenta is attached;
each product of such a birth is considered live born
- All
live-born infants should be registered and counted as such irrespective of
gestational age or whether alive or dead at time of registration, and if they
die at any time following birth they should also be registered and counted as
deaths
Source: WHO
Live Birth Registration
* The United Nations recommends that
the following be collected at a minimum for live birth registration:
Ø Data on event
• Date of
occurrence • Date of registration
• Place of occurrence • Type of birth/delivery
• Attendance at birth
Ø Data
on infant:
•Sex •Legitimacy status • Weight at birth
Ø Data on mother:
• Age or
date of birth
•Number of
previous children born alive
• Date of
marriage or duration of marriage
•Place of
usual residence
Death Registration
Death—Permanent
disappearance of all evidence of life at any time after live birth has taken
place (post-natal cessation of vital functions without capability of
resuscitation) Š
This definition excludes fetal deaths
Source: WHO
Fetal Death —Death prior to the complete
expulsion or extraction from its mother of a product of conception,
irrespective of the duration of pregnancy .
--The death is indicated by the fact
that after such separation the fetus does not breathe or show any other
evidence of life, such as beating of the heart, pulsation of the umbilical
cord, or definite movement of voluntary muscles
Fetal Death Categories:
Three major
categories of fetal deaths recommended by WHO:
– Early
fetal death: < 20 completed weeks of gestation
–
Intermediate fetal death: ≥ 20 but < 28 weeks
– Late fetal
death: ≥ 28 weeks
Stillbirth:
Stillbirth—Late
fetal death Š
To be used only if essential for national
purposes
Death Registration : The United Nations recommends that the following be collected
at the minimum for death registration.
Ø Data on event:
• Date of
occurrence • Date of
registration
• Place of
occurrence • Cause of death
• Certifier
Ø Data on decedent:
• Age or date of birth • Sex • Marital status
• Occupation • Place of usual residence
Problems with Cause of Death Data:
i.
Knowledge
of certifier
ii.
Certifier
may never see deceased
iii.
“Garbage
codes”: missing, senility, etc
iv.
Heart versus brain function loss in the
definition of death
v.
Multiple
and contributory causes of death
vi.
Medical
classification changes over time
vii.
François
de la Croix
viii.
John Graunt
WHO and the
International Classification of Diseases (ICD); now at version 10
Classification of Cause of Death from
John Graunt in 1662
• Bleeding • Killed by several accidents
• Burnt and scalded • Murdered
• Drowned • Poisoned
• Excessive drinking • Smothered
• Frightened • Shot
• Grief • Starved
• Hanging • Vomiting
Note:
causes of death can be regrouped in smaller categories than in ICD – e.g.,
Preston’s classification of causes of death in 12 categories
Preston’s Classification of Causes of
Death
•Respiratory
•Degenerative
diseases (ulcers of stomach, diabetes)
•Other
infections and parasitic •Complications of pregnancy
•Neoplasms •Diseases
of infancy
•Cardiovascular
Š •Motor vehicle accidents
•Influenza,
pneumonia, and bronchitis •Other
accidents and violence
•Diarrhea,
gastritis, enteritis •Other
Š Š
Marriage Registration :
Marriage—Ceremony or process by which the
legal relationship of husband and wife is constituted.
The legality of the union may be established
by civil, religious, or other means as recognized by the laws of each country
Source:
United Nations
The United
Nations recommends that the following be collected at a minimum for marriage
registration:
Ø Data on event
• Date of
occurrence • Date of registration
• Place of occurrence • Type of marriage—civil, religious,
customary
Ø Data
on bride and groom
• Age or
date of birth • Previous marital status
• Place of
usual residence
Divorce
Registration :
Divorce—Final legal dissolution of a
marriage, that is, that separation of husband and wife which confers on the
parties the right to remarriage under civil, religious and/or other provisions,
according to the laws of each country.
Source:
United Nations
Civil Registration:
Evaluation
of coverage and content
– Matching
studies
– Aggregate demographic analysis
Cost : – High
Advantages
of Civil Registration :
i.
Continuous monitoring of vital rates
ii.
May provide both numerator and denominator for
some rates (e.g., Infant Mortality Rate—IMR)
iii.
Small
area data available
iv.
Base for testing the accuracy of censuses and
surveys Continued
Disadvantages of Civil Registration:
i.
Uncertain
coverage: Difficult to ensure registration of all the events
ii.
Limited
background information
iii.
Time reference often inconsistent with
denominator definition
iv.
Information may come from third party
v.
Easily
disrupted by political/economic events
vi.
Literacy/numeracy
vii.
Costly
Points to Watch in Data:
-
Coverage
(always evaluate for developing countries)
-
Delayed registration
-
Classification
done by place of residence or place of occurrence?
-
Treatment
of non-response
-
Other
issues
Personal Identification Number (PIN) :
-
Method
used in Israel, South Africa, Sweden, and Thailand
-
Each
individual is assigned a unique number used for the rest of his/her life on all
pertinent documents in the national data system
-
System
acts as a census because it is continuously updated by births, deaths,
immigrants, and emigrants
Summary
-
Demography
is the study of a population in its static and dynamic aspects.
-
Civil registration is a system developed to
collect data on vital events (live births, deaths, marriages and divorces)
happening to a population .
-
Civil registration is continuous and universal
(it should give small area data).
-
The cost is high, but not having the
information may be more costly.
-
There are advantages and disadvantages to the
system and its completeness varies widely between countries and continents.
-
The
United Nations has recommended a minimum list of information to collect on each
type of event .
-
To that list, individual countries add data
that they believe is necessary for better monitoring of their specific
situation.
Censuses
:
Census—The total process of collecting,
compiling, analyzing, and publishing or otherwise disseminating demographic,
economic, and social data pertaining to all persons in a country or in a
well-delineated part of a country at a specified time
Source:
United Nations
Essential Characteristics:
i.
Universality
ii.
Simultaneity Š
iii.
Individual
enumeration
iv.
Egypt 3000 B.C.
v.
“Census”
every other year
vi.
List of families and other occupants of houses
for certain particular cases (e.g., soldiers)
Ø Greece
–
Count of males 18 years and older
Ø Rome
-
Enumeration
of every family every five years for taxation purposes Š
Ø England 1066
-
Domesday book
Modern
census:
– Format
emerged gradually around 1600s in Europe
– Quebec
1666
– England 1841 (first real census)
– 1850 (first time to list individuals in
U.S.)
Content and Types
A census contains:
-
Demographic
data (at least age and sex)
-
Economic
data (e.g., occupation and income)
-
Social (e.g., education and housing
Example – 1990 census content as regard to
population (adapted from U.S. Department of Commerce, Census 1990 Basics)
100-percent component
-
Household
relationship
-
Sex
-
Race
-
Age
-
Marital
status
-
Hispanic origin
Sample component
Social characteristics:
-
Education (enrollment and attainment)
-
Place
of birth, citizenship, and year of entry into the United States
-
Ancestry
-
Language
spoken at home
-
Migration
(residence in 1985)
-
Disability
-
Fertility
-
Veteran status
Economic
characteristics:
-
Labor force
-
Occupation,
industry, and class of worker
-
Place
of work and journey to work
-
Work
experience in 1989
-
Income
in 1989
-
Year last worked
A
census can be conducted:
-
De jure:
Legal or customary attachment to an area (you are registered where you usually
reside)
-
De
facto: Physical residence (you are registered where you are currently
staying/residing at the time of the census)
Importance of Census:
Importance of Census:
The importance of the census lies in its being an integrated
picture of society in a given time within numerous, multiple and continuous
changes, which cannot be defined through other data collecting methods. The
census provides a suitable database for comparisons and projections of
demographic data as well as social and economic characteristics of society.
A comprehensive census is different from other statistical methods in the following ways:
A comprehensive census is different from other statistical methods in the following ways:
1.
It provides
comprehensive and detailed data on the whole population in addition to
demographic, social and economic characteristics by the lowest administrative
or geographical level and related rates and indicators (population growth
rates, age and gender composition, educational features, Qatari and non-Qatari workforce).
2.
It provides necessary
data enabling the assessment of the population status in Qatar during the
inter-census period as well as monitoring demographic, social and economic
changes taking place during the same period in various administrative divisions.
3.
It provides data on
expatriates' number, distribution and characteristics in Qatar, especially the
immigrant workforce, with a high degree of precision, instead of dependence on
estimates.
4.
It provides a database
on which are built population projections and workforce projections.
5.
It provides a database
needed to study specific social phenomena.
6.
To provide basic data
for all sectors in the country (education, health, population, etc.) with a
view to contributing to the formulation, monitoring and evaluation of plans
related to the provision of services needed by the Qatari society.
7.
To provide necessary
frameworks for deriving samples for field research to be undertaken in the
future.
8.
To provide data on
housing units as well as their facilities and features related to living
conditions, basic data needed to work out a clearly-defined housing policy
aimed at ensuring prosperity for citizens, as well as indicators on houses
conditions and extent of their relationship with public services.
9.
To provide a
comprehensive and modern framework for buildings, houses and households by
various administrative divisions. Such framework is necessary to design and use
samples for conducting various household surveys. This will be positively
reflected on the accurate measurement of the various phenomena to be
investigated such as fertility, mortality and migration, which are used as the
basis for calculating population growth rates and estimates of the post-census
population.
10.
To provide an accurate
picture of the status and features of houses for the purpose of assisting in
drawing up housing and construction plan for the future.
11.
To provide data on the
features of buildings of the public sector and private sector and status of
their occupation so as to define various needs in the future.
To define the conditions of
economic and social enterprises in the public and private sectors in terms of
the legal status, economic activity and workforce size by gender and
nationality.
Use Of Census
Population and housing census aims mainly at
collecting and disseminating basic statistics including age, sex and
relationship to head of household and other characteristics such as education
and occupation at a specified period of time. Following are some uses of the
census data.
1) Development planning
purposes
2) Estimation of levels and variations in population and housing characteristics
2) Estimation of levels and variations in population and housing characteristics
3) Estimating sources of
labor force
4) Identifying the role
of women and their economic and social standing
5) Learning about special population groups
6) Use for research purposes
7) Use for economic purposes
8) Census data will identify
a comprehensive frame for all active5) Learning about special population groups
6) Use for research purposes
7) Use for economic purposes
Data Collection Procedures :
-
Establish
administrative tree (census officers, supervisors, enumerators)
-
Develop questionnaire(s)
-
Cartography
-
Define
enumeration areas
-
Pretest
enumeration processes
-
Design
data processing system
-
Enumeration
(postal with follow-up, general canvas)
Cost:
-
Estimates
-
$10
per head in the U.S.
-
$1
per head in most developing countries
Advantages:
-
Universal,
hence small area data available Š
-
National
effort
-
Provides frame for later sample surveys Š
-
Provides
population denominators
Disadvantages :
-
Size
limits content and quality control efforts
-
Cost
limits frequency
-
Delay
between field work and results
-
Sometimes
politicized
Imputation Technique :
-
To
assign values to “Unknowns”
-
Cold deck: use the frequency distribution of
known cases
-
Hot
deck: take values from previous case with same other characteristics
Points to Watch in Data:
-
Population
definition
-
Coverage
change between censuses
-
Treatment
of non-response
-
Imputation
technique
Summary
-
Censuses
are universal, simultaneous and require individual enumeration.
-
A
census can be conducted de jure, de facto or some combination .
-
Preparing
a census is a meticulous process including many steps .
-
Censuses
should give small area data, although coverage is not always certain.
-
The
cost is high, but not having the information may be more costly.
-
Censuses
should be evaluated to estimate the quality of the data; several techniques
exist for that purpose.
-
There
are advantages and disadvantages to the system.
Surveys
Purpose:
-
Obtain
information from a sample representative of some population
-
Content
– Varies widely – e.g., fertility, child mortality, migration
Essential
Characteristics :
-
Representative
sample of some population
-
Smaller
size than census allows collection of more in-depth information that can then
be generalized
Types of Surveys :
Single-round retrospective
-
Census-type
household surveys
-
Focused,
(e.g., Contraceptive Prevalence Survey (CPS))
-
Birth/Maternity
history (World Fertility Survey (WFS), Demographic and Health Survey (DHS))
-
Health
monitoring
-
Summary
of DHS
Multi-round follow-up (prospective)
Sampling Methods :
·
Sampling
frame, generally from census
·
Separate strata are often defined for sampling
-
The provinces of a country could be strata or
urban and rural areas
-
There
may be multiple strata
·
Census
enumeration areas or sections of them may constitute a cluster from which
households are sampled (clusters are typically sampled within strata and then
households within clusters)
·
Sample
size may range from one to four thousand women to hundreds of thousands of
people
·
Sampled
clusters may range from 20 to 400 or more
Cost :
-
In
the 1990s, ranged approximately from $10 to $150 per capita
-
Least
expensive method
Advantages
:
·
Single-round retrospective
i.
Can
be quick
ii.
Relatively
inexpensive
iii.
Flexible
iv.
Can
include detailed data
v.
Needs
little continuity effort
Advantages:
·
Multi-round prospective
i.
Some
control on coverage and content errors
ii.
Follow-up
allows control for sampling distortion
Disadvantages:
·
Single-round retrospective
i.
Coverage
and content errors
ii.
Misses
certain types of events
·
Multi-round prospective
i.
Slow
ii.
Needs
continuity of effort over (extended) time
iii.
High
cost
Summary
-
Surveys
are done to obtain information from a sample representative of some population
-
Surveys are of a smaller size than a census,
which allows for collection of more in-depth information that can then be
generalized
-
There are many types of surveys
-
The
sampling method used in surveys is often multistage (e.g., household within
cluster, themselves taken within strata)
-
Surveys
are less expensive than censuses and civil registration (smaller size allows
for quick collection of more in-depth information than any of the other two
systems)
They have advantages and disadvantagesKeep Visiting
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