U.S. Census Bureau, Census 2000
Modified Race Data Summary File

2000 Census of Population and Housing

Technical Documentation

Overview: Why a Modified Race File

POPULATION ESTIMATES AND PROJECTIONS

This Modified Race Summary File contains modified race categories based on Census 2000 data tabulated by age, sex, and Hispanic origin for counties in the United States and Puerto Rico. The Census Bureau’s Population Estimates Program modified the Census 2000 race data for use in the production of post-2000 population estimates and projections. The modification reconciles the Census 2000 race categories with those race categories that appear, or will appear, in the data from administrative records, which are used to produce population estimates and projections. The modification in this summary file did not correct or adjust the Census 2000 procedures for tabulating or coding race data, nor was it corrected for undercoverage or duplication of persons in Census 2000.

CENSUS 2000 RACE CATEGORIES

Many state and local agencies comply with the U.S. Office of Management and Budget (OMB) 1997 revised standards for the collection, tabulation, and presentation of federal data on race and ethnicity.2 The revised OMB standards identify a minimum of five racial categories: White; Black or African American; American Indian and Alaska Native; Asian; and Native Hawaiian and Other Pacific Islander. Perhaps, the most significant change for Census 2000 was that respondents were given the option to mark one or more races on the questionnaire to indicate their racial identity. Census 2000 race data are shown for people who reported a race either alone or in combination with one or more other races.

To allow Census 2000 respondents who could not identify with any of the above five OMB race categories another option, the questionnaires, with OMB's approval, included a sixth race category: “Some other race.” Space was provided on the questionnaire to allow respondents to also write in their race if their response was “Some other race.” Because of needs to have census data comparable with the reporting categories used by state and local agencies and for compiling other administrative data used in producing population estimates and projections, the Census Bureau developed a procedure to assign an OMB race to those who reported "Some other race." (For more information about race classifications in Census 2000, visit the Census Bureau’s Internet site: Racial and Ethnic Classifications Used in Census 2000 and Beyond.)

RACE MODIFICATIONS

This summary file provides data from Census 2000 that have been modified to assign each of the persons in the “Some other race” category to an OMB race category. The modified race data include 31 race groups which are the single and multiple race combinations of the OMB race categories: White; Black or African American; American Indian and Alaska Native; Asian; and Native Hawaiian and Other Pacific Islander. (For a list of the 31 race groups shown in this summary file, see Figure 1 in Chapter 1.)

In Census 2000, there were roughly 18.5 million people who identified "Some other race" as part of, or their only, race response. These people were primarily of Hispanic origin, 90.4 percent or 16.8 million people, and many wrote in their Hispanic origin or Hispanic origin type (such as Mexican or Puerto Rican) as their race. Since these people were not included in one of the five OMB race categories, it was necessary to modify their race. Responses of “Some other race alone” were modified by blanking the “Some other race” response and imputing an OMB race category, either alone or in combination with another race. Race responses were imputed from a “donor,” who matched on Hispanic origin. Responses of both “Some other race” and an OMB race(s) were modified by blanking the "Some other race" response and using the OMB race response(s) that was provided. No modification was made for responses indicating only an OMB race alone or in combination with another race. (A more detailed explanation on the procedures used for race modifications is found in Chapter 3.)

Procedure: Race Modification

INTRODUCTION

The following describes the modifications used to reconcile the Census 2000 race categories with those race categories that appear in the data from administrative records, which are used to produce population estimates and projections.

DEFINITIONS

A. A specified race response is a response of one or more of the five Office of Management and Budget (OMB) race categories: White; Black or African American; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander.

B. A non-specified race response is a response of “Some other race.”

CATEGORIZATION OF CENSUS 2000 RACE RESPONSES

A. Single or multiple race responses that include only specified OMB races.

B. Single race responses of a non-specified race (Some other race alone).

C. Two or m ore race responses that include both the specified OMB race(s) and the non-specified response, “Some other race.”

MODIFICATION PROCEDURES

A. No modification was made for race responses where only a specified OMB race was provided alone or in combination with one or more OMB races (e.g., White alone, White and Black or African American; White and Black or African American and American Indian and Alaska Native).

B. Non-specified race responses of “Some other race” alone were modified by blanking the non-specified race response and allocating a specified OMB race alone or in combination. Race was allocated from a donor within the household that matched on Hispanic origin. If a donor could not be found within the household, a race was allocated from a hot deck matrix where the donor and donee matched on the specific Hispanic origin (Not Hispanic or Latino; Mexican; Puerto Rican; Cuban; Central American and Dominican; South American; other Spanish).

C. Race responses of both specified and non-specified races were modified by blanking the non-specified race and using the specified OMB race(s). For example, White and Some other race became White alone; White and Black or African American and Some other race became White and Black or African American.

RACE ALLOCATION GUIDELINES

A. Within household race allocation:

1) Donors and donees must match on the specific Hispanic origin (Not Hispanic or Procedure 3-2 U.S. Census Bureau, Census 2000 Latino; Mexican; Puerto Rican; Cuban; Central American and Dominican; South American; other Spanish).

2) Donors were permitted to have a race and Hispanic origin that was allocated or edited as part of the Census 2000 edit procedures.

3) Donors were permitted to have a race that was modified.

4) The within-household allocation was consistent with the household relationship guidelines used in Census 2000 procedures.

B. Race allocation from the hot deck matrix:

1) Donors and donees must match on specific Hispanic origin (Not Hispanic or Latino; Mexican; Puerto Rican; Cuban; Central American and Dominican; South American; other Spanish).

2) Donors could not have a race or Hispanic origin that had been allocated or edited as part of the Census 2000 procedures.

3) Donors could not have a race that had been modified.

4) Donors were permitted to have an edited age but had to be in the same broad age range (0-14, 15-34, 35-54, 55+).

5) Hot deck guidelines were consistent with the Census 2000 procedures.

RESULTS

Compared to Census 2000 data, the effect of the race modification shows an increase in the U.S. population that reported only “One race” and a decrease in the population that reported “Two or more races” (see Tables 1 and 2 at the end of this chapter).

·        For the total population, the single race population grew from 97.57 percent to 98.62 percent, a difference of 1.05 percentage points in the percent distribution (Table 1).

·        For the total population, the Two races population decreased from 2.26 percent to 1.27 percent, a decrease of 0.99 percentage points. This decrease occurred primarily because nearly half of the two races population reported Some other race and exactly one of the five OMB races (Table 1).

·        For the total population, the Three or more races population decreased from 0.16 percent to 0.11 percent, a decline of 0.05 percentage points (Table 1).

·        As expected, the increase in the specific single race groups due to the modification is proportional to the size of the group in Census 2000.

·        The total White population, the largest racial group in both percent and number, experienced the largest increase due to the modification, increasing from 75.14 percent to 81.05 percent, an increase of 5.91 percentage points in the percent distribution (Table 1).

·        The total Native Hawaiian and Other Pacific Islander population, the smallest racial group in both percent and number, experienced the smallest increase due to the modification, increasing from 0.14 percent to 0.16 percent, an increase of 0.02 percentage points in the percent distribution (Table 1).

·        Both the Hispanic and Not Hispanic population followed a similar pattern with increases in the population reporting only One race and decreases in the population reporting Two or more races. The percentage point change was greater for the Hispanic population.

·        Changes after the modification are consistent for both the Hispanic and Not Hispanic populations.

Data Availability

The 2000 Census Modified Race Data Summary File is available on a CD-ROM, which contains population counts for all counties in the United States and municipios in Puerto Rico by 5-year age group, sex, Hispanic origin for the 31 modified race categories. The 31 race groups are the single and multiple race combinations of the OMB race categories: White, Black or African American, American Indian and Alaska Native, Asian, Native Hawaiian and Other Pacific Islander.

The general public may purchase copies of the CD-ROM for $50.00 by contacting: Marketing Service Office, Customer Services Center, U.S. Census Bureau, Washington, DC 20033.  Phone 301-763-4636.