Transcript Chapter 4

Chapter 4
Demographic Data
Chapter Outline
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Sources Of Demographic Data
Population Censuses
Registration Of Vital Events
Combining The Census And Vital
Statistics
Administrative Data
Chapter Outline
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Sample Surveys
Historical Sources
Demographic Uses Of Geographic
Information Systems
Where Can You Go For Information?
Who Uses Population 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
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.
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
Census Errors:
Nonsampling
• Coverage error
 People who are missed or who are
counted more than once.
• 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.
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.
Difficulties Using Data
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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.
Sample surveys
 Used frequently to gather
demographic data.
 Provide less extensive geographic
coverage than a census or system of
vital registration.
Geographic Hierarchy of
Census Data
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2.
3.
4.
5.
6.
United States
Region (4)
Division (9)
State (50)
County
County
Subdivision
7. Place
8. Census
Tract/Block
Numbering
9. Block Group
10.Census Block
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.