Geographic Areas for Neighborhood-Level Analysis

Using ACS Data

Michael Ratcliffe

Geography Division

US Census Bureau

1

Which census geographic areas relate to neighborhoods?

• Block Groups– Subsets of census tracts

– Population range: 600 to 1,200

• Census Tracts– Population range: 1,200 to 8,000; optimum 4,000

• ZIP Code Tabulation Areas– Census block-based representations of ZIP Codes

• Places– Incorporated places

– Census designated places (unincorporated places)

2

Data for Small Geographic Areas

3

2005-2009 2006-2010 2007-2011

Block Groups 2000 Census 2010 Census 2010 Census

Census Tracts 2000 Census 2010 Census 2010 Census

Incorporated Places

2009 2010 2011

Census Designated Places

2000 Census* 2010 Census 2010 Census*

ZIP Code Tabulation Areas

No updates since 2002; not included in data

No updates since 2002; not included in data

2010 Census

* CDP boundaries may be modified as a result of annexations by adjacent incorporated places, or if the community incorporates.

4

Places and census tracts, Baltimore city and Baltimore County

Tracts may subdivide places in densely settled areas, but will encompass multiple communities in rural areas.

5

Baltimore neighborhoods and tracts

6

Neighborhoods and tracts do not always align.

7

Block groups, tracts, and neighborhoods

8

Starr County, Texas

Current places with colonias and 2010 census designated places

9

Colonias defined as CDPs, Starr County, Texas. Colonias are generally smaller than tracts and block groups.

ZIP Code Tabulation Areas and Census Tracts

10

In DC, census tracts subdivide ZIP codetabulation areas.