Racial Segregation in urban-rural
continuum: do patterns vary by
geographical region?
Yosef Bodovski
Master in GIS & Population Research Institute
The Pennsylvania State University
E-mail: yub107@psu.edu
Academic Advisor: Dr. Chris Benner, Department of
Geography
Definitions:
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Metropolitan Area is a large population center consisting
of a large city and its adjacent zone of influence.
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Principal City is the largest city in Metro Area.
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Urban-Rural Continuum is a classification scheme that
distinguishes geographic units by population size and
adjacency to a Metro Area.
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Residential Segregation refers to the unequal distribution
of groups across space.
Recent Demographic Trends in US Metros
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The fast growing Metro Areas in 1980s and 1990s
become slow growing in 2000s.
South and West Metros become a major population
growth centers.
The fastest-growing Metros rely on domestic migration
and natural growth while slow growing Metros rely on
immigration.
Most of the Central Cities have similar trends as their
Metro Areas
Source: W.Frey (2005) Metro America in the New Century: Metropolitan and Central City
Demographic Shifts since 2000. The Brooking Institution – Living Census Series.
U.S. Census Geography:
Project Data:
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Source: Census Summary File 1 (SF1)
Years: 2000 and 1990
Geographic Level: Block
Variables:
* White not Hispanic
* Black not Hispanic
* Asian not Hispanic
* Hispanic
Shapefiles: Block Level Boundary Files.
Source: U.S. Census Bureau Web Site www.census.gov
Measures of Spatial Segregation
The Index of Dissimilarity (Black vs. White):
d=(1/2)sum( | b (i) / B – w (i) / W |)
Where:
b (i): black population in areal unit (block)
B: total black population in Metro Area
w (i): white population in areal unit (block)
W: total white population in Metro Area
Measures the evenness with which two mutually exclusive groups are
distributed across the geographic units that make up a larger
geographic entity (Metro Area).
Source: Reardon S., Firebaugh G. (2002) Measures of Multi Group Segregation,
Sociological Methodology 32 (1) pp. 33-67
Measures of Spatial Segregation
The isolation index:
I = sum (w (i) / W) * (w (i) / t (i))
Where:
w (i): white population in areal unit (block)
W: total white population in Metro Area
t (i): total population in areal unit (block)
Reports the percentage white in areal unit for the typical average white
person. Measures concentration or isolation of one race group.
Source: Reardon S., Firebaugh G. (2002) Measures of Multi Group Segregation,
Sociological Methodology 32 (1) pp. 33-67
Measuring Spatial Segregation using dissimilarity index
Metro Area as a Whole Unit
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Dissimilarity indexes generally declined between 1990 and
2000 for all race groups
White-Black segregation remained high (d>0.8) in Traditional
North (Chicago, Detroit, Philadelphia) and Old South (Atlanta,
Birmingham) metros; decreased (d<0.4) in West (Portland,
SF) and New South (Dallas, Miami) metros.
White-Hispanic segregation is slightly higher in North East
(average d=0.44), mixed patterns in the rest of he country
White-Asian segregation has significantly declined between
1990 and 2000 (average d=0.47) in all areas.
Source: W. Frey, D. Myers (2005) “Racial Segregation in US Metro Areas and
Cities 1990-2000”, Population Center Research Report, University of
Michigan
Measuring Spatial Segregation using dissimilarity index
Principal City vs. Suburbs
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Racial diversity in suburban areas rose substantially in the last
decade.
“Melting Pot” Metros (New York, Chicago, Los Angeles) have the
highest minority suburban population.
Minorities are responsible for the bulk of suburban population gains
in 1990s.
Asians are more likely to live in major metropolitan suburbs than in
cities.
People who identify themselves as belonging to more than one race
show different suburbanization patterns.
Source: W. Frey (2001) Melting Pot Suburbs: A Census 2000 Study of Suburban
Diversity. Population Center Research Report. University of Michigan.
Measuring Spatial Segregation using dissimilarity index
Metro Classification by Suburban Diversity Patterns
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Melting Pot Metros (Chicago, New York, Los Angeles)
Southern White-Black Metros (Atlanta, Nashville,
Birmingham)
Mainly White South and West Metros (Seattle, Tampa,
Denver)
North White-Black Metros (Philadelphia, Cleveland, Detroit)
Mainly White North Metros (Boston, Minneapolis,
Cincinnati)
Source: W. Frey (2001) Melting Pot Suburbs: A Census 2000 Study of Suburban
Diversity. Population Center Research Report. University of Michigan.
Measures of Spatial segregation
The Information Theory Index:
H = sum (( t (i) ( E – E (i) )) / ET
Where:
t (i): total population in areal unit
E: metro area diversity (entropy)
E (i): areal unit diversity (entropy)
T: total metro area population
Reports weighted average deviation of each unit’s diversity from the
study area diversity.
Source: Reardon S., Firebaugh G. (2002) Measures of Multi Group Segregation,
Sociological Methodology 32 (1) pp. 33-67
Measuring Spatial Segregation using Information Theory Index
Metro Area as a Whole Unit
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The diversity and segregation measures show that diversity
increased substantially over the period between 1990 and 2000 and
segregation declined.
Segregation is higher for Black and White race groups
Midwest Metro Areas have the highest segregation indexes followed
by Northeast, South and West.
Metro Areas with bigger population and higher percent of minorities
have higher segregation indexes
Source: J. Iceland (2002) Beyond Black and White – Metropolitan Residential
Segregation in Multi-Ethnic America. Housing and Economic Statistics Division.
U.S. Census Bureau
Project Inputs
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Use The Information Theory Index (H) as segregation
measure since it takes into account more than two race
groups at a time.
Use Census Block as a basic areal unit.
Use 100 most populated US Metropolitan Areas as Macro
Units
Use data from 2000 and 1990 Census surveys
Use Population Density of Census Blocks as a measure of
Urban-Rural Division. Break up each Metro Area into four sub
areas (quartiles) according to Census Block Population
density.
Project Assumptions
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Racial Segregation is higher in places with high
population density.
Racial Segregation is higher in Traditional North and Old
South Metros than in the rest of the country.
Racial Segregation has declined between 1990 and
2000, in both urban and suburban areas.
The gap between top quartile (high density) and bottom
quartile (low density) has declined in most of Metro
Areas
Project Outputs
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Calculate Information Theory Index (H) for each sub area in 100
Metropolitan Areas for 1990 and 2000 Census Data.
Compare indexes…
a) …in the same area across the time
b) …in the same type of sub area across the
country
c) …in the same type of sub area inside five
groups defined by Frey (2001)
d) …in the same type of sub area between five
groups defined by Frey (2001)