Chapter 4
Demographic Data
Sources of Demographic
Data
• Census of population
 population, demographic structure and
characteristics.
• Registration of vital statistics
 population processes of births and
deaths
• Administrative data
 Local population changes, geographic
mobility and migration
Other Sources of
Demographic Data
• Historical Records – Family Bibles, Church
records. Ships Manifest
• Population Registers. – Complete
demographic history of individuals.
Census of Population
• The term “census” is from the Latin
word meaning to assess.
• Ancient censuses differed from
modern censuses because they were
largely used for taxation and
military purposes
Populations in the Census
• de facto population - people who are in
a given territory on census day
• de jure population - people who legally
“belong” to a given area, regardless of
whether they were there on the day of
the census
• people included in the census on the
basis of usual residence - roughly
defined as the place where a person
usually sleeps (U.S., Canada, Mexico)
Census of Population
• Both China and India conducted censuses
early in the twenty-first century.
• The Canadian, Mexican, and U.S.
censuses use a both a 100% short form
and a more detailed sample form.
Which Area of the World is least likely to have had
its populations recently enumerated in a Census?
D
C
B
A
Problems with Censuses
• No census has been taken in
Lebanon since before World War II.
• Census was cancelled in the
Netherlands in 1980’s
• Nigerian Census in 1991 occurred
only after agreeing on no questions
concerning ethnic groups.
Population Census
 U.S.:
Censuses have been taken
every 10 years since 1790.
 Canada: Censuses have been
taken every 10 years since 1851
and every 5 years since 1951.
 Mexico: Censuses have been
taken every 10 years since 1900,
and every 5 years since 1990.
What we learn from the U.S.Census
• Reapportionment of the House of
Representatives (Most important)
• Provides data for Federal Funding
Formulas
• Basic Demographic Data for the
United States
Controversies with the U.S. Census.
• Counting of African slaves.
 3/5 compromise.
• Undercounting minorities
• Counting Homeless persons.
• Counting of illegal aliens.
Differential Undercounting
Administrative Records
• Demographic information derived from
administrative records, including tax
returns, utility records, school
enrollment, and participation in
government programs.
Administrative Records
• Bills of Mortality. – First used by John
Graunt to study infant mortality.
• Draft registration
 WWI draft registration
demonstrated the undercount of
African-Americans.
Vital Statistics
• The two most important demographic
events recorded by vital statistics are
births and deaths.
• Vital statistics and survey data are
necessary to accurately estimate the
rate of population growth in the years
between censuses.
Combining data from different sources
provides clearer picture of change.
• Vital Statistics provide information on
births and deaths.
• Administrative data to provide
information on migration.
• Census data is often combined with
other sources of data to calculate
rates.
Demographic Balancing Equation
P2=P1+B-D+I-O
•
•
•
•
•
P2-Population(time 2)
P1-Population(time 1)
B-Births D-Deaths
I–In-migration
O= Out-migration
Demographic Balancing Equation
• Vital Statistics

(Births – Deaths) = Natural Increase.
• Administrative data – IRS.
 In – Out Migration = Net
Migration.
Variations of the Demographic
Balancing Equation
• Net Migration = Pop(t2) – Pop(t1) –
Deaths + Births.
Census Errors:
Nonsampling
• Content Error
 Problems with the accuracy of the data
obtained in the census.
• Includes nonresponses to particular
questions on the census or inaccurate
responses if people do not understand the
question.
Content Error
• Example 1. Single Mom living with adult son
and his girlfriend. Identifies girlfriend as
unmarried partner meaning her sons unmarried
partner.
• Example 2. Persons of Hispanic descent listing
other race then filling in hispanic or latino.
• Example 3. Questionaire fatigue.
Coverage error
Measuring coverage error in a census?
• demographic analysis
 demographic balancing equation
• dual system estimation
 A.C.E. Accuracy and Coverage
Evaluation.
Sample surveys
 Used frequently to gather
demographic data.
 Provide less extensive geographic
coverage than a census or system of
vital registration.
Sampling Errors
• If any data in a census are collected on a
sample basis, sampling error is
introduced in the results.
• Sampling error is readily measured based
on the mathematics of probability.
• Samples can be designed to ensure
comparable levels of error across groups.
Sample surveys
• United States
 American Community Survey (ACS)
 Current Population Survey (CPS)
• Canada
 Labor Force Survey (LFS)
• Mexico
 Encuesta Nacional de Ocupacion y Empleo
• Demographic and Health Surveys (DHS)
Sample surveys
• Demographic and Health Surveys (DHS)
 170 surveys conducted in more than 70
developing countries in Africa, western
Asia and Latin America.
Demographic Health Survey
• Focused on fertility, reproductive
health and child health and nutrion.
• Serves as a substitute for vital
statistics in many developing
nations.
Difficulties Using Data
•
Data collected in the census, by the vital
statistics registration system, or derived
from administrative records:
1. Usually collected for purposes other than
demographic analysis and do not reflect
the theoretical concerns of demography.
2. Collected by many different people using
different methods and may be prone to
numerous kinds of error.
Geographic Information
Systems (GIS)
• Computer-based system that brings maps
together with data in innovative ways.
• Geo-referencing data to places on the
map means different types of data can be
combined for the same place, and for
more than one time.
• Increases the ability to visualize and
analyze demographic changes over time
and space.
Mississippi Counties by Percent Black 1940-2000
Census Geography