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Government 90dnMapping the Census
Lecture 4: Geographical Units
Sumeeta Srinivasan
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Outline for Today Geographical Units in Census
How to compare across time/ space
Discussion
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Major Units: Blocks, Census Blocks, TractsSource: http://www.census.gov/geo/www/geo_defn.html
Blocks, Block groups, tracts do not cross the
boundaries of any entity for which the U.S.Census Bureau tabulates
Tabulation blocks are identified uniquely within
census tract and block groups
Census 2000 collection blocks, block groups
and tracts are numbered uniquely within county(or statistically equivalent entity)
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Major Units: CountiesSource: http://www.census.gov/geo/www/geo_defn.html
The primary legal divisions of most states are
termed counties. In Louisiana, these divisions are known as
"parishes"
In Alaska, statistically equivalent entities are
organized boroughs and the census areas
Maryland, Missouri, Nevada, and Virginia haveone or more incorporated places that are
independent cities
DC is one county
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Major Units: County subdivisionsSource: http://www.census.gov/geo/www/geo_defn.html
Census county divisions CCD, census subareas,
minor civil divisions MCD, and unorganizedterritories
The boundaries of CCD, MCD etc. follow visible
features, and coincide with census tracts whereapplicable
CCD delineated by Census 21 states (includes
Alabama)
MCDs are the governmental or administrative
divisions of a county in 28 states (includes Mass.)
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Major Units: Metropolitan AreasSource: http://www.census.gov/geo/www/geo_defn.html
Concept of a metropolitan area (MA): large population nucleus,
with communities that have economic/ social integration
Each MA must contain a place with minimum population 50,000
or a U.S. Census Bureau-defined urbanized area
An MA contains one or more central counties (with specified
level of commuting)
Classified as:
Metropolitan statistical area (MSA) or
Consolidated metropolitan statistical area (CMSA) divided into primary
MSA (PMSAs)
If MA has more than 1 million people 2 or more PMSAs may be
defined
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Metropolitan Areas Each MSA, PMSA and CMSA was assigned a unique 4-digit
FIPS code, inherited usually from Standard Metropolitan
Statistical Areas SMSA of the same or similar name in previousCensus.
For Massachusetts:
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Major Units: PlacesSource: http://www.census.gov/geo/www/geo_defn.html
Place is a concentration of population
Include census designated places CDP, consolidated cities, and
incorporated place
CDPs are delineated to provide data for population that are
identifiable by name but are not legally incorporated
A consolidated city is a unit for which the functions of an
incorporated place and its county or MCD merged
An incorporated place is established for governmental functions
for a concentration of people as opposed to a MCD created to
provide services or administer an area without regard to
population
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Places
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Major Units: Urban or RuralSource: http://www.census.gov/geo/www/geo_defn.html
U.S. Census classifies as urban all territory,
population, and housing units located within an
urbanized area (UA) or an urban cluster (UC)
An urban cluster (UC) consists of densely settled
territory that has at least 2,500 people but fewer than50,000 people
An urbanized area (UA) consists of densely settled
territory that contains 50,000 or more people. A UAmay contain both place and nonplace territory
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UA and UC For Massachusetts:
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Comparing across geographic unit
and time
Across time:http://mcdc2.missouri.edu/websas/geocorr2k.ht
ml
Across unit:
http://www.census.gov/popest/geographic/bound
ary_changes/
http://mcdc2.missouri.edu/websas/geocorr2k.htmlhttp://mcdc2.missouri.edu/websas/geocorr2k.htmlhttp://www.census.gov/popest/geographic/boundary_changes/http://www.census.gov/popest/geographic/boundary_changes/http://www.census.gov/popest/geographic/boundary_changes/http://www.census.gov/popest/geographic/boundary_changes/http://mcdc2.missouri.edu/websas/geocorr2k.htmlhttp://mcdc2.missouri.edu/websas/geocorr2k.html