1. U.S. Census Overview
SOC 101

2. Outline of Presentation
Census History
Census Questionnaire
Census Geography
Census Data
American FactFinder

3. Census History Survey of the United States population every 10 years
Mandated by Constitution
Purpose: reapportionment of 435 seats in the House of Representatives

4. Census Questions Vary Over Time
Total population, race, sex in 1790
(650 enumerators counted 3,929,214 people at a cost of $44,337)
Physical and Mental Disabilities in 1830
Income first asked in 1940
Televisions surveyed,
Detailed ancestry beginning 1980
Multiple races and grandparents as caregivers in 2000
(500,000 enumerators counted 281,421,906 people at a cost of $4.5 billion)

5. Census Questions Vary Over Time
Reflects changes in society
In 1990 and 2000 Congress wanted to reduce paperwork
Grid of questions,

6. Practical Applications for Census Data
Public health professionals identify vulnerable
populations for chronic disease
Urban planners identify zoning, housing, sewage, and transportation issues
Social workers conduct needs assessments for
services to the elderly, poor, children

7. Practical Applications for Census Data
Marketers target likely buyers
Politicians use the census to determine voting
districts and to assess constituent interests
Environmentalists map the spread of toxic effluents
and population densities

8. Practical Applications for Census Data
Occupation by age, race, and sex for equal
employment opportunity
Librarians base collection development policy on
community characteristics
Mayors use numbers to apply
for federal grants.
Undercount costs money
Identify communities of
interest or need
CENSUS 2000 SHORT FORM (SF1) HISPANICS AS A PERCENT OF TOTAL POPULATION

9. 2000 Questionnaires 100% and Sample
Age
Sex
Race (Multiple)
Hispanic origin
Household relationship
Occupied v. vacant housing units
Owner v. renter occupied housing

10. Primary Uses of Short Form Data
Race and sex for single years of age to 99; three groups after 100
Most detail by race (250 groups total)

11. Race Groups in 2000 White Black or African-American
American Indian or Alaskan Native
Asian
Hawaiian or Pacific Islander
Other
Two or More Races
(Based on Self-Identification)

12. Household Relationships
Relationship to Householder
Spouse
Child
Stepchild
Grandchild
Brother/Sister
Parent
Non-relative
Unmarried partner is separate category

13. 2000 Sample Questionnaire (generally 1/6 of population)
Marital status, housing value and rent (100% in 1990)
Grandparents as caregivers (new)
Ancestry
Language
Country of origin
School enrollment and educational attainment (and dropouts)

14. 2000 Sample Questionnaire Employment Industry and occupation
Transportation to and place of work
Disability and mental illness
Veteran status
Income and poverty

15. American Community Survey (ACS)
Started in 1996 to address 2-3 year lag in availability of decennial census data
Annual sample of 3,000,000 households (long form)
Decennial census will still be conducted, but will only include short form
Will enhance the usefulness of the census for planning efforts
Some concerns about sampling error and undercounts
Between 1940 and 2000 the undercount of African Americans was much greater than non-African Americans
Men also tend to be undercounted more than women

16. Census Geography
This diagram shows the hierarchical relationships between geographic types.
For example, a line extends from states to counties because a state is comprised of many counties, and a single county can never cross a state boundary.

17. If no line joins two geographic types, then an absolute and predictable relationship does not exist between them.
For example, many places are confined to one county. However, some places extend over more than one county, such as New York City.
Therefore, an absolute hierarchical relationship does not exist between counties and places, and any tabulation involving both these geographic types may represent only a part of one county or one place.
Census Geography

18. Census Geography
Notice that many lines radiate from blocks, indicating that most geographic types can be described as a collection of blocks, the smallest geographic unit for which the Census Bureau reports data.
However, only two of these lines also describe the path by which a block is uniquely named. That is, the path through the Block Group.

19. Census Geography Map

20. Urban Areas Urbanized = Densely settled area, 50,000+
Urban Cluster = Densely settled area,
,000; can be outside metro area

21. Metropolitan Statistical Area
Central city of 50,000 or more
Its own county, and
Surrounding counties with heavy commuting patterns
Entire counties belong to MSAs

22. MSA Definitions This is very complicated
Just consult the definitions when you need them

23. Census Tracts
Areas of about 4000 people
Approximate neighborhoods

24. Block Group Two – eight block groups per tract
Smallest area for sample data

25. Census Data Sources American FactFinder
A web-based tool developed by the Census Bureau to provide census data on the Web
Will probably suffice for all but the most complex analyses
Provides useful first glance at the data before you construct your own analysis

26. Sources U.S. Census Bureau http://www.census.gov American FactFinder
Census Toolkit
Census Tutorials
Numeric and Spatial Data Services Library, University of Michigan
Community and Regional Planning Program of The University of Texas at Austin School of Architecture, “Working with 2000 Census Data in ArcGIS,”
Peters, A. and H. MacDonald Unlocking the Census with GIS. ESRI Press.
Redlands, CA.