Download - U.S. Census Overview
Outline of Presentation
Census History Census Questionnaire Census Geography Census Data
American FactFinder
Survey of the United States population every 10 years
Mandated by Constitution
Purpose: reapportionment of 435 seats in the House of Representatives
Census History
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, 1950-70
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)
Census Questions Vary Over Time
Reflects changes in society
In 1990 and 2000 Congress wanted to reduce paperwork
Grid of questions, 1790-2000http://www.lib.umich.edu/govdocs/census2/censubj.pdf
Census Questions Vary Over Time
Public health professionals identify vulnerable populations for chronic disease
Urban planners identify zoning, housing, sewage, and transportation issues
Social workers conduct needs assessments forservices to the elderly, poor, children
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 effluentsand population densities
Practical Applications for Census Data
Occupation by age, race, and sex for equal employment opportunity
Librarians base collection development policy oncommunity characteristics
Mayors use numbers to apply for federal grants.
Undercount costs money Identify communities of
interest or need
Practical Applications for Census Data
CENSUS 2000 SHORT FORM (SF1)HISPANICS AS A PERCENT OF TOTAL
POPULATION
2000 Questionnaires100% and Sample
100% Questionnaire Age Sex Race (Multiple) Hispanic origin Household relationship Occupied v. vacant housing units Owner v. renter occupied housing
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)
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)
Household Relationships
Relationship to HouseholderSpouseChildStepchildGrandchildBrother/SisterParentNon-relativeUnmarried partner is separate category
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)
2000 Sample Questionnaire
Employment Industry and occupation Transportation to and place of work Disability and mental illness Veteran status Income and poverty
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
Census GeographyThis 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.
Census GeographyIf 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
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.
Urban AreasUrbanized = Densely settled area, 50,000+
Urban Cluster = Densely settled area, 2500-50,000; can be outside metro area
Metropolitan Statistical Area
Central city of 50,000 or more Its own county, and Surrounding counties with heavy commuting patternsEntire counties belong to MSAs
MSA Definitions
This is very complicated
Just consult the definitions when you need them
http://www.census.gov/population/www/estimates/metrodef.html
Census Data Sources
American FactFinder http://factfinder.census.gov/
•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
Sources U.S. Census Bureau
http://www.census.gov American FactFinder
http://factfinder.census.gov/ Census Toolkit
http://www.lib.umich.edu/govdocs/census2/centool.pdf Census Tutorials
Numeric and Spatial Data Services Library, University of Michigan http://www.lib.umich.edu/nsds/
Community and Regional Planning Program of The University of Texas at Austin School of Architecture, “Working with 2000 Census Data in ArcGIS,”
http://mather.ar.utexas.edu/Courses/parmenter/gis/arcgis_tips/census2000/index.html
Peters, A. and H. MacDonald. 2004. Unlocking the Census with GIS. ESRI Press.Redlands, CA.