Demographic Data

1
Chapter 4

• Demographic Data

2
Chapter Outline

• Sources Of Demographic Data
• Registration Of Vital Events
• Combining The Census And Vital
• Administrative Data
• Sample Surveys
• Historical Sources
• Demographic Uses Of Geographic Information Systems

3
Population Center of the U.S. States Based on
Data from Decennial Censuses
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Sources of Demographic Data

• Census of population
• population, demographic structure and
  characteristics.
• Vital statistics
• population processes of births and deaths
• Administrative data
• Local population changes, geographic mobility and
  migration

5
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.

6
Most Countries Conducted a Census Between 2000
and 2005
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Comparison of Items Included in Census for U.S.,
Canada, and Mexico
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Comparison of Items Included in Census for U.S.,
Canada, and Mexico
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Comparison of Items Included in Census for U.S.,
Canada, and Mexico
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Comparison of Items Included in Census for U.S.,
Canada, and Mexico
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Comparison of Items Included in Census for U.S.,
Canada, and Mexico
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Comparison of Items Included in Census for U.S.,
Canada, and Mexico
13
Comparison of Items Included in Census for U.S.,
Canada, and Mexico
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Comparison of Items Included in Census for U.S.,
Canada, and Mexico
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Comparison of Items Included in Census for U.S.,
Canada, and Mexico
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Comparison of Items Included in Census for U.S.,
Canada, and Mexico
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Who Is Included 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

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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.

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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.

20
Net Undercount and Differential Undercount in
U.S. Censuses
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Difficulties Using Data

• Data collected in the census, by the vital
  statistics registration system, or derived from
  administrative records
• Usually collected for purposes other than
  demographic analysis and do not reflect the
  theoretical concerns of demography.
• Collected by many different people using
  different methods and may be prone to numerous
  kinds of error.

22
Sample surveys

• Used frequently to gather demographic data.
• Provide less extensive geographic coverage than a
  census or system of vital registration.

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Geographic Hierarchy of Census Data

• United States
• Region (4)
• Division (9)
• State (50)
• County
• County Subdivision

• Place
• Census Tract/Block Numbering
• Block Group
• Census Block

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Elements of Geodemographics
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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.