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Updates
and Technical Notes
Updates
- 10/27/03.
Completed integrated "Metro and City Info" webpages. The integrated pages allow a user to
access any information the Mumford Center has for cities, states, or metropolitan areas
from a single page. Links to Mumford Center reports and news articles written about Mumford
Center projects are also available on the integrated webpages.
- 10/21/03.
Updated the "Homeowners and Renters" using adjusted SF2 data. To overcome data
suppression applied by the Census, the Mumford Center developed a procedure to fill in
missing values. A detailed technical note outlining the procedure employed by the
Mumford Center is available
here.
- 9/15/03.
Completed "Occupational Change: Metropolitan America, 1990-2000" webpages.These pages
provide 1990 Census occupation number employed converted to their equivalent Census 2000
categories for a consistently defined 2000 metropolitan region geography. For comparison,
we also provide the conversion counts for metropolitan regions under their 1990 geographic
definitions (as available from the Census Bureau's
American FactFinder
web site).
- 9/01/03.
Released report:"Segregation in Neighborhoods and Schools: Impacts in Minority Children
in the Boston Region." Prepared for presentation at the Harvard Color Lines Conference,
this report describes residential patterns and their consequences for school segregation
and school inequality using data from the 2000 census and 1999-2000 school year.
- 8/15/03.
Updated "The Muslim World in Metropolitan America" (released:10/07/02)
and "Black Diversity in Metropolitan America" (released: 2/17/03) using
extractions from the Census 2000 1% Public Use Microdata Sample (2000
PUMS). Although the C2SS (original data source) and 2000 PUMS are
weighted samples, the 2000 PUMS is larger (a 1-in-100 national random
sample) than the C2SS (a 1-in-750 national sample drawn from 1203
counties) and thus provides more accurate population estimates. For a
more detailed description of these data sources please refer to the
technical documentation available at the Census website
(www.census.gov).
- 2/27/03. Completed update to the "Separate and
Unequal" and "Dimensions of Segregation" web pages, including
information for all cities with populations greater than 10,000. These
data are available for 1990 and 2000, not adjusting for changes in city
boundaries over time.
- 2/27/03. Completed update to the "Segregation
- Children (under 18)," "Homeowners and Renters," "The
New Americans," State of the Cities," "Separate and Unequal,"
"Diversity in Black and White," web pages, using corrected
metro boundaries for 1990. The changes are slight, and there were no
changes in most metro areas.
- 12/20/02. Added
information to the "Segregation: whole population" web pages.
1) Added population counts and segregation indices for cities with populations
greater than 10,000. These data are available for 1980, 1990 and 2000,
not adjusting for changes in city boundaries over time. 2) Added the
2000 "adjusted" census counts (released by the Census Bureau
in December 2002) for total population and for each major racial/ethnic
group (for individual cities, as well as metro areas).
- 11/19/02. Released
"Technical Report: Comparability of the 2000 and 1990 Census Occupation
Codes." Using this crosswalk, analysts will know which detailed
occupation categories in 1990 and 2000 can be combined to create a consistent
management/professional category.
- 11/6/02. Added
new set of web pages based on SF3 tract data: "Dimensions of Segregation."
These pages provide measures of segregation between households with
different incomes, between immigrants and natives, as well as measures
of racial segregation controlling for income or nativity.
- 11/5/02. Updated
the "Segregation - whole population" web pages, using corrected
metro and central city boundaries for 1990. In a few cases, these are
significant changes.
- 10/15/02. Released
12th report: "Separate and Unequal: The Neighborhood Gap for Blacks
and Hispanics in Metropolitan America." Based on SF3 tract data
(and comparable data for 1990), this report points out the continuing
income disparities among races and the increasing disparities in the
quality of their neighborhoods. It demonstrates that affluent minorities
experience as large a neighborhood gap as do poor minority households.
- 10/7/02. Released
revision and update of the "Muslim World in Metropolitan America"
report, including information from SF3 tract data showing the numbers
and locations of people with origins in predominantly Muslim countries.
The report also uses data from the Census 2000 Supplemental Survey to
show the relatively high economic and educational profile of this population.
- 10/1/02. Completed
two sets of web pages based on SF3 tract data."Separate and Unequal"
provides information on group differences in income and nativity, and
examines their effects on neighborhood inequalities."Diversity
in Black and White" provides information on the size and neighborhood
locations of white and black subgroups: European white ancestry groups,
people with birth or ancestry in predominantly Muslim countries, and
blacks with African birthplaces or Afro-Caribbean ancestry. NOTE: These
pages include corrections in our procedure to match the 1990 and 2000
geography of some cities and metropolitan regions. Corrections to other
data sets are in progress.
- 6/24/02. Released
11th report: "The Suburban Advantage." Based again on the SF3 Profiles,
the report shows large and generally increasing economic disparities
between cities and suburbs, although in a few places (like Chicago and
Seattle) cities began to catch up with their suburbs.
- 6/19/02. Added
sortable lists and downloadable data files for metro area SF3 Profiles.
- 6/5/02. Released
10th report: "Regional Divisions Dampen '90s Prosperity: New Census
Data Show Economic Gains Vary by Region." Based on the SF3 Profiles
of Census 2000, this report documents the rebound of the Rustbelt since
1990, continued catching up by metro areas in the South, and relative
stagnation or decline in the Northeast and Southern California.
- 5/20/02. Added
two sets of web pages to report information from the SF3 Profiles as
they were released by the Census Bureau: "State of the Cities" and "New
Americans."
- 5/8/02. Released
ninth report: "Hispanic Populations and Their Residential Patterns in
the Metropolis." This report analyzes differences in the residential
patterns of people from specific Hispanic national origins, trends in
segregation and formation of distinctive Hispanic enclaves in the metropolis.
- 3/28/02. Issued
revised school segregation report. The revised report is based on data
on children in elementary grades, regardless of the grade range of their
school. Added web pages to report information for several thousand school
district for 1989-1990 and 1999-2000.
- 12/18/01. Released
eighth report: "Choosing Segregation: Racial Imbalance in American Public
Schools, 1990-2000." This report was based on data on elementary schools
(defined as schools beginning in pre-K or K) from the National Center
for Education Statistics. Added web pages to report information by metropolitan
region and by school district for 1989-1990 and 1999-2000.
- 11/19/01. Released
seventh report: "The Muslim World in the United States," based on data
from the 1990 Census of Population and the pooled 1998-2000 samples
of the Current Population Survey.
- 11/19/01. Released
sixth report: "From Many Shores: Asians in Census 2000," based on data
from the 1990 and 2000 Census of Population, and nativity and socioeconomic
data from the pooled 1998-2000 samples of the Current Population Survey.
Added information on Asian national-origin population counts for states
and individual metropolitan regions (1990 and 2000) to the website.
- 11/9/01. Issued
corrected population counts and segregation indices for the under-18
population in 1990. In several large metro areas with substantial minority
populations, the new indices reveal higher segregation of children in
1990 than previously reported. Files downloaded before this time should
be updated.
- 10/26/01. Added
1980 data to the website and downloadable files. Corrected estimates
of segregation for 1990, using STF1A full-count tract data in place
of STF3A sample data; this has a large effect in metro areas with small
minority populations.
- 9/10/01. Released
fifth report: "The New Latinos: Who They Are, Where They Are" to replace
"Immigrant Enclaves in the American Metropolis." Added estimates of
the size of specific Hispanic national-origin groups to the website.
- 7/9/01. Released
fourth report: "The New Ethnic Enclaves in America's Suburbs."
- 9/6/01. Second
geographic adjustment, using census tract equivalency files as a method
of maintaining constant 2000 metropolitan, city, and suburb designations.
- 7/5/01. Website
redesigned to accommodate release of additional types of data and reports.
Released third report based on preliminary analyses: "Immigrant Enclaves
in the American Metropolis."
- 5/6/01. Children
segregation data added to the site, with an accompanying report: "Living
Separately: Segregation Rises for Children."
- 4/3/01. Released
first report: "Ethnic Diversity Grows, Neighborhood Integration Is at
a Standstill."
- 3/30/01. First
geographic adjustment, using 2000 metropolitan and city/suburb boundaries
for 1990 data.
- 3/11/01. Census
website received its first visitors.
Technical Notes
- The 2000 Census
is the first to allow respondents to list up to four different racial/ethnic
categories to describe themselves. There was also a separate question
about Hispanic origin. This allows for numerous ways of categorizing
individuals into racial and ethnic groups. Our purpose has been to identify
categories on non-Hispanic white, non-Hispanic black, Hispanic, and
Asian, as similar as possible to the way those categories were defined
in the 1990 Census.
Coding for 1980 and 1990 is as follows. All Hispanics are included in
the Hispanic category, regardless of race. Asians and Pacific Islanders
are reported as a single category by the census. Hispanic Asians are
included in both the Hispanic count and the Asian count. This is because
the STF4 files in 1980 and 1990, which allow analysts to introduce information
such as income and education into studies of racial groups, also include
Hispanic Asians in the tables both for Hispanics and for Asians. Because
there are few Hispanic Asians, this choice has little practical importance.
Coding for 2000 is much more complicated. Our procedure has undergone
some adjustments over time. As a result of variations in how Census
2000 treats race in various tabulations that we rely on, we use slightly
different definitions on different web pages.
On all pages, we use the following rules for classifying "Hispanic"
and "non-Hispanic white" in 2000:
- We
code as "Hispanic" any person listed as Spanish/Hispanic/Latino,
regardless of what they answered for the race/ethnicity question.
- We
code as "non-Hispanic white" non-Hispanics who answered only "white"
as their race.
The data provided on the "Segregation-Whole Population" and
"Segregation-Children (under 18)" classify "non-Hispanic
black" and "Asian" for 2000 as follows:
- We
code as "non-Hispanic black" any non-Hispanic who indicated
that they were Black or African-American, regardless of any other
race/ethnicity they may have indicated.
- We
code as "Asian" any remaining non-Hispanic (individuals not already
classified as non-Hispanic white or non-Hispanic black) who indicated
that they were Asian or Pacific Islander, regardless of any other
race/ethnicity they may have indicated.
On all other pages, we define non-Hispanic black and Asian for 2000
as follows:
- We code as "non-Hispanic black" any non-Hispanic,
non-Asian who indicated that they were Black or African-American.
This means that "black Asians" are not counted as black.
- We
code as "Asian" anyone who indicated that they were Asian
alone, or in combination with one or more races, and with one or
more Asian categories.
The treatment of Asians in these other web pages introduces several
changes from the definition used in the "Segregation-Whole Population"
and "Segregation-Children (under 18)" pages:
- Pacific Islanders are not included (unless they also
reported being Asian).
- People
who reported two different Asian ethnicities (e.g. Japanese and
Filipino) are double-counted.
- Hispanic Asians
are counted as Asian and also as Hispanic.
- Data
from Census 2000 are from the full-count PL-794 and SF1 files. Initially
the 1990 population counts and segregation indices were calculated from
tract-level data from STF3A, which is based on the long-form sample.
In October 2001 we discovered that there are large discrepancies in
segregation indices between sample data and full-count data in metro
areas where the minority population is less than 1-2% of the total.
We now rely entirely on full-count data.
- In order to differentiate
between central city and suburban census tracts, we used data from the
"split tract" summary level for all of our calculations. Tracts
are "split" when they straddle place boundaries. In the 2000
data, some tracts also straddle voting district boundaries. These units
have been aggregated in order to maintain comparable tract sizes, and
number of tracts, across years.
- The 2000 census
data are now based on the new metropolitan boundaries for 2000. In order
to maintain comparability across years, we have re-configured the 1980
and 1990 metropolitan boundaries to match those of 2000. We also followed
the most recent definition of central cities. Using this method, we
were able to link all metro areas for 1990 and 2000. For 1980, some
small metropolitan regions cannot be included, because their territory
had not been tracted.
The geography for this website, including downloadable data files, has
varied over time:
- Initially
the 1990 data were based on 1990 metropolitan boundaries and city/suburb
classifications.
- A geographic
adjustment on 3/30/01 brought 1990 data into line with 2000 boundaries.
We used FIPS place codes to determine which tracts should be located
in each metropolitan area. One shortcoming of this method is that
places with a population of less than 10,000 cannot be identified.
In these cases, tracts were assigned to their original 1990 msa/pmsa
location. The same method was used to determine whether a tract
was located in a central city or a suburb.
- A second geographic
adjustment on 9/6/01 used tract equivalency files from the Bureau
of the Census to attach the 2000 metropolitan area code to each
tract in 1980 and 1990. We view this as the optimal method of constructing
2000 metropolitan boundaries in 1990, and it is limited in 1980
only to the extent that some areas were untracted. Some tracts that
were split across place boundaries in 2000 could not be precisely
linked to an equivalent split tracts in 1980 or 1990, so we could
not use their 2000 central city or suburb designation for them.
Where all portions of the tract were in city or suburban places,
this posed no problem. In cases where part of the tract was central
city and part was suburban in 2000 (such tracts include 1.42% of
the 1990 metropolitan population), we assigned the earlier year's
designation to it.
The following links provide definitions of the components of metropolitan
areas as established by the Office of Management and Budget.
- Click
here
to view a list of the counties contained within
each metropolitan area.
- Click
here
to view a list of the central cities contained
within each metropolitan area.
- You must enable
java in your browser's preferences in order to view the full content
of this site. If java is not enabled, you will not see the pie charts
on the metropolitan area data pages.
- The following formulas
were used to generate segregation scores. The examples give here are
for white/black indices, but the same formulas may be used for all combinations
of groups.
Where:
B = the metropolitan black population
Bi = the black population
of tract i
W = the metropolitan white population
Wi = the white population
of tract i |
Where:
B = the metropolitan black population
Bi = the black population
of tract i
Ti = the total population
of tract i |
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