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Participant Statistical Areas Program for the 2010 Census
Michael RatcliffeIndiana GIS ConferenceMarch 13, 2007
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Participant Statistical Areas
• Census Tracts
• Block Groups
• Census Designated Places
• Census County Divisions
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Topics Geography Division reexamined
• Current relevance and use of these geographies
• Needs of the data user community
• Validity of existing thresholds
• Accommodating ACS data• Minimum thresholds for data reporting • Population vs. housing unit counts
• Through: • Geography Division research• Consultation with Census Bureau stakeholders
(ACS team leaders, statisticians, and others)• Consultation with non-Census Bureau stakeholders
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No substantial changes to criteria
• All PSAP geographies are recognizable in:• Concept and purpose• Coding and naming conventions• Boundary features permitted
• Things done informally in operational guidelines in the past are made clear and consistent in the criteria
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Census Tracts
• Nationally consistent small, statistical geographic units
• Boundary continuity for data comparability
• Data reliability
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Census Tracts: Considerations for the 2010 Census
• All types of populated tracts meet the same thresholds• National standard• Reliability of sample data
• Change minimum population threshold to 1,200
• Reliability of sample data • Avoid application of disclosure avoidance
methodologies
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Census Tracts: Considerations for the 2010 Census
• Housing unit counts or population counts to meet thresholds
• Accommodate ACS data
Census 2000 Proposed for the 2010 Census
Population Population Housing Unit
Optimum 4,000 4,000 1,600
Minimum 1,500 1,200 480
Maximum 8,000 8,000 3,200
Thresholds
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Indiana Census Tracts
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Census Tracts: Tippecanoe County
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Block Groups (BGs)
• BGs nest within census tracts
• Smallest area for ACS sample data tabulation
• Continuity and comparability from one census to another less of a concern
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Block Groups:Considerations for the 2010 Census
• All types of populated BGs meet the same thresholds
• National standard• Reliability of sample data
• Increase the minimum thresholds • Sample data reliability • Avoid application of disclosure avoidance
methodologies
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Block Groups:Considerations for the 2010 Census
• Housing unit counts or population counts to meet thresholds
• Accommodate ACS data
Census 2000 Proposed for the 2010 Census
Population Population Housing Unit
Optimum 1,500 --- ---
Minimum 600 1,200 480
Maximum 3,000 3,000 1,200
Thresholds
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Tracts and Block Groups:Considerations for the 2010 Census
Special land use tracts and block groups
• Areas of 1 sq. mile or more within an urban area, 10 sq. miles outside
• No residential population
• Has an official name• Large public parks, large public forests
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Tract and Block Groups: Considerations for the 2010 Census
Special land use areas
Source: NPS
Central Park, NY1.3 mi2
Lava Beds National Monument, CA73 sq mi2
Source: NPS
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Tract and Block Groups: Considerations for the 2010 Census
Why define special land use tracts and block groups?
• Clarify and cohere current practice
• Enhance thematic mapping of data
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Tribal tracts and tribal block groups • Unique geographic framework separate from the
county-based census tracts and block groups that are defined nationwide
• Equivalent to county-based census tracts and block groups
• Improve data relevance, availability, and reliability for American Indian tribes
Implications: • Standard, county-based census tracts defined
nationwide (wall-to-wall coverage) • Tribal tracts are a completely separate set of geography
for data presentation purposes
Tract and Block Groups: Considerations for the 2010 Census
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Census Designated Places
• Place-level statistics for well-known, settled unincorporated communities;
• Statistical equivalents of incorporated places;
• Mix of residential, commercial, and retail areas around a nucleus of relatively high residential population density
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Census Designated Places:Considerations for the 2010 Census
• CDPs cannot have zero population and zero housing units • Zero population and housing units is contrary
to the concept of “place”
• Not allow CDPs to be defined coextensively with governmentally functioning MCDs in the 12 “strong-MCD” states • Reduce redundancy in data presentations
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Number of CDPs and Incorporated Places in the US, Puerto Rico, and the Island Areas: 2000
CDPsIncorporated
Places
United States 5,698 19,452
Puerto Rico 225 0
American Samoa 0 73
Guam 32 0
CNMI 16 0
USVI 6 3
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Distribution of CDPs and Incorporated Places by Population
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
CDPs
Inc Places
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Indiana Places
Incorporated Places: 567
Mean Population: 6,851
Median Population: 1,137
Census Designated Places: 34
Mean Population: 3,363
Median Population: 1,741
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Indiana CDPs by Population
0
5000
10000
15000
20000
25000
30000
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Indiana CDPs
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Census County Divisions
• Set of sub-county units that have stable boundaries and recognizable names;
• Provide comparable set of sub-county geographic areas for longitudinal analysis;
• Represents one or more communities, trading centers, or major land uses;
• Can have more CCDs than census tracts in counties with small populations
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Census County Divisions
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Census County Divisions:Considerations for the 2010 Census
Options:
1. Retain the CCD concept
2. Eliminate the CCD concept and do not replace with another type of sub-county geographic unit
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Participant Statistical Areas Program
• Regional, multi-county organizations, (e.g. COGs, MPOs) preferred primary participant• To reflect local input and the needs of
a wide range of data users• Participation open to all interested
parties • MAF/TIGER Participant Software for
electronic submission of boundaries
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Participant Statistical Areas Program
• Proposed criteria published in Federal Register in Spring 2007
• 90 day public review and comment period• Final criteria published late 2007• Participants identified late 2007 – early 2008• Materials distributed: Summer 2008• Participants will have 120 days to review
and submit boundaries
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Comments and Suggestions?
Geographic Standards and Criteria Branch (GSCB)
301-763-3056April Avnayim, Vince Osier, & Mike Ratcliffe
www.census.gov/geo/www/psap2010/psap2010_main.html
