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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

geo.psap.list@census.gov

www.census.gov/geo/www/psap2010/psap2010_main.html