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Appendix A. Technical Note and Guide to Sources

U.S. Department of Commerce

Census Bureau

American Community Survey

The American Community Survey (ACS) is a sample survey conducted by the U.S. Census Bureau. The ACS was first implemented in 1996 and expanded in scope in subsequent years; it replaced the long-form survey in the 2010 Decennial Census.

 Tables 3, 15a, and 24a report ACS data.

For more information on the ACS, see

Current Population Survey
The Current Population Survey (CPS) is a monthly survey of about 60,000 households conducted by the U.S. Census Bureau for the Bureau of Labor Statistics. The CPS is the primary source of information on the labor force characteristics of the U.S. noninstitutionalized population (i.e., it excludes military personnel and their families living on bases as well as inmates of institutions). In addition, supplemental questionnaires are used to provide further information about the U.S. population. Specifically, in October, detailed questions are asked about school enrollment and school characteristics. In March, detailed questions are asked about income.

The current sample design, introduced in July 2001, includes about 72,000 households. Each month about 60,000 of the 72,000 households are eligible to be interviewed; of the eligible households, 7 to 8 percent are not interviewed because of temporary absences or unavailability. Information is obtained each month from those in the household 15 years of age and older and demographic data are collected for children 0–14 years of age. Prior to July 2001, data were collected in the CPS from about 50,000 dwelling units. The samples are initially selected based on the decennial census files and are periodically updated to reflect new housing construction.

The estimation procedure employed for monthly CPS data involves inflating weighted sample results to independent estimates of characteristics of the civilian noninstitutional population in the United States by age, sex, and race. These independent estimates are based on statistics from decennial censuses; statistics on births, deaths, immigration, and emigration; and statistics on the population in the armed services. Generalized standard error tables are provided in the Current Population Reports; methods for deriving standard errors can also be found within the CPS technical documentation at The CPS data are subject to both nonsampling and sampling errors.

Caution should be used when comparing data from 1994 through 2001 (which reflect 1990 census-based population controls) with data from 1993 and earlier (which reflect 1980 or earlier census-based population controls), as well as with data from 2002 onward (which reflect 2000 census-based controls). Changes in population controls generally have relatively little impact on summary measures such as means, medians, and percentage distributions. They can, however, have a significant impact on population counts. For example, use of the 1990 census-based population control resulted in about a 1 percent increase in the civilian noninstitutional population and in the number of families and households. Thus, estimates of levels for data collected in 1994 and later years will differ from those for earlier years by more than what could be attributed to actual changes in the population. These differences could be disproportionately greater for certain subpopulation groups than for the total population.

Tables 4, 5, 8, 15, 17, 24, 25, 25a, 26, 27, 28, 30, 30a, 31, 31a, 32, 32a, 36, 38 and 41 use CPS data.

For more information on the CPS, see

Decennial Census, Population Estimates, and Population Projections

The Decennial Census is a universe survey mandated by the U.S. Constitution. It is a questionnaire sent to every household in the country, and it is composed of seven questions about the household and its members (name, sex, age, relationship, Hispanic origin, race, and whether the housing unit is owned or rented). The Census Bureau also produces annual estimates of the resident population by demographic characteristics (age, sex, race, and Hispanic origin) for the nation, states, and counties, as well as national and state projections for the resident population. The reference date for population estimates is July 1 of the given year. With each new issue of July 1 estimates, the Census Bureau revises estimates for each year back to the last census. Previously published estimates are superseded and archived.

Census respondents self-report race and ethnicity. In the 2000 Census, they were first asked, “Is this person Spanish/Hispanic/Latino?” and then given the following options: No, not Spanish/Hispanic/Latino; Yes, Puerto Rican; Yes, Mexican, Mexican American, Chicano; Yes, Cuban; and Yes, other Spanish/Hispanic/Latino (with space to print the specific group). The next question was “What is this person’s race?”, and the options were White; Black, African American, or Negro; American Indian or Alaska Native (with space to print the name of enrolled or principal tribe); Asian Indian; Japanese; Native Hawaiian; Chinese; Korean; Guamanian or Chamorro; Filipino; Vietnamese; Samoan; Other Asian; Other Pacific Islander; and Some other race. The last three options included space to print the specific race. The 2000 Census was also the first time that respondents were given the option of choosing more than one race. The Census population estimates program modified the enumerated population from the 2000 Census to produce the population estimates base for 2000 and onward. As part of the modification, the Census Bureau recoded the “Some other race” responses from the 2000 Census to one or more of the five OMB race categories used in the estimates program (U.S. Department of Commerce 2008). Prior to 2000, the Census Bureau combined the categories Asian and Native Hawaiian or Other Pacific Islander. For all years, all persons of Hispanic origin were included in the Hispanic category regardless of the race option(s) chosen. Therefore, persons of Hispanic origin may be of any race.

Tables 1, 2, 3, 6, 29, and 39 use data from the Decennial Census and the Census population estimates and projections program.

For more information, see

Statistical Abstract of the United States

The Statistical Abstract of the United States, published since 1878, is the authoritative and comprehensive summary of statistics on the social, political, and economic organization of the United States. Sources of data include the Census Bureau, Bureau of Labor Statistics, Bureau of Economic Analysis, and many other federal agencies and private organizations.

Table 39 reports data from the Statistical Abstract of the United States.

For more information on the Statistical Abstract of the United States, see