The Current Population Survey (CPS) is a monthly survey of about 60,000 households from the 50 states and the District of Columbia. It is conducted by the Census Bureau, which is part of the U.S. Department of Commerce, for the Bureau of Labor Statistics. The survey has been conducted for more than 50 years.
The CPS sample is scientifically selected to represent the civilian, noninstitutional U.S. population. This includes the household population, people living in noninstitutional group quarters, and members of the military living off post or with their families on post. Thus, inmates in correctional institutions and patients in long-term medical or custodial facilities are not included in the sample, nor are military personnel living in barracks. Interviewers ask a knowledgeable adult household member (known as the "household respondent") to answer all of the month's questionnaires for all members of the household. Respondents are interviewed to obtain information about the employment status of each member of the household age 15 or older. However, published data focus on those age 16 and over. The sample provides estimates for the nation as a whole, as well as for individual states and other geographic areas.
Estimates obtained from the CPS include employment, unemployment, earnings, hours of work, and other measures. They are available by a variety of demographic characteristics, including age, sex, race/ethnicity, marital status, and education attainment. They are also available by occupation, industry, and class of worker (e.g., government, private, self-employed). Supplemental questions to produce estimates on topics such as school enrollment, income, previous work experience, health, employee benefits, and work schedules are often added to the regular CPS questionnaire.
Each year, the Annual Social and Economic (ASEC) Supplement and October supplemental questionnaires contain questions of relevance to education policy. The ASEC Supplement, formerly known as the March CPS Supplement, is a primary source of detailed information on income and work experience in the United States. The October Supplement routinely gathers data on school enrollment, school characteristics, and educational attainment for elementary, secondary, and postsecondary education. Related data are also collected about preschooling and the general adult population. In addition, NCES funds additional items on education-related topics such as language proficiency, disabilities, computer use and access, student mobility, and private school tuition. Responses are collected for all household members age 3 and over.
CPS interviewers initially used printed questionnaires. However, since 1994, the Census Bureau has used Computer-Assisted Personal and Telephone Interviewing (CAPI and CATI) to collect data. These technologies allow interviewers to administer a complex questionnaire with increasing consistency and reductions in interviewer error. In 1994, the survey methodology for CPS was changed, and weights were adjusted. For more information on CPS data collections, please visit http://www.census.gov/apsd/techdoc/cps/cps-main.html.
The following section contains definitions of selected variables that are used in The Condition of Education 2011. Further information on the CPS can be found at http://www.census.gov/cps.
Definitions of Selected Variables
Indicator 18 examines employment status using data from the ASEC Supplement, which contains questions on the employment of adults in the previous week. Respondents can report that they were employed (either full or part time), unemployed (looking for work or on layoff), or not in the labor force (due to being retired, having unpaid employment, or some other reason).
Indicator 45 looks at employment status using data from the October CPS and its supplement, which also contains questions on employment of adults in the previous week. In this indicator, employed persons are persons age 16 or older who, during the reference week, (1) did any work at all (at least 1 hour) as paid employees or (2) were not working but had jobs or businesses from which they were temporarily absent because of vacation, illness, bad weather, child care problems, maternity or paternity leave, labor-management dispute, job training, or other family or personal reasons, whether or not they were paid for the time off or were seeking other jobs.
Hours Worked per Week
Indicator 45 presents data from the October CPS and its supplement on the number of hours worked per week. This estimate is the number of hours a respondent worked in all jobs in the week prior to the survey interview. The population for this variable includes any employed person who also worked in the week prior to the survey interview. The sum of the categories may not equal the total percentage employed because those who were employed but did not work in the previous week were excluded.
Indicator 21 uses data on family income, collected as part of the October CPS, to measure a student's economic standing. The October CPS determines family income from a single question asked of the household respondent. Family income includes all monetary income from all sources (including jobs, businesses, interest, rent, and social security payments) over a 12-month period. The income of nonrelatives living in the household is excluded, but the income of all family members age 15 or older (age 14 or older in years prior to 1989), including those temporarily living outside of the household, is included.
In indicator 21, family income of a recent high school graduate is defined as the income of the household where the graduate has membership. A household is defined as the group of individuals whose usual place of residence at the time of the interview is the sample unit. The following considerations guide the determination of household members:
Families in the bottom 20 percent of all family incomes are classified as low income; families in the top 20 percent of all family incomes are classified as high income; and families in the 60 percent between these two categories are classified as middle income. Exhibit B-4 shows the current dollar amount of the breakpoints between low and middle income and between middle and high income that are used in indicator 21. For example, the income for low-income families in 2009 ranged from $0 to $18,000; for middle-income families, from $18,100 to $86,700; and for high-income families, from $86,800 and higher.
Exhibit B-4. Dollar value (in current dollars rounded to the nearest hundreds) at the breakpoint between low- and middle-income and between middle- and high-income categories of family income: October 1975–2009
Indicator 17 uses data on earnings that are collected as part of the March CPS. The March CPS collects information on earnings from individuals who were full-year workers (individuals who were employed 50 or more weeks in the previous year) and full-time workers (those who were usually employed 35 or more hours per week). Earnings include all wage and salary income. Unlike mean earnings, median earnings either do not change or change very little in response to extreme observations.
Over time, the CPS has had different response options for race/ethnicity. From 1972 through 1988, the response options were limited to White, Black, Hispanic, and Other. From 1989 through 1995, the response options were White, Black, American Indian/Aleut Eskimo, Asian/Pacific Islander, Hispanic, and Other. In 1996, Census revised procedures for editing and allocating the race variable to offset an underestimation of data on American Indians and Asians/Pacific Islanders. One should use caution when making comparisons between data from 1995 and earlier and data from 1996 and later. From 1996 through 2002, the response options were White, Black, American Indian/Aleut Eskimo, Asian/Pacific Islander, and Hispanic. Since 2003, the response options have been White, Black, American Indian/Alaska Native, Asian, Hawaiian/Pacific Islander, and Hispanic, and respondents have been allowed to select two or more race categories. In The Condition of Education 2011, persons of Hispanic ethnicity are classified as Hispanic regardless of their race response(s). Thus, the race/ethnicity categories are mutually exclusive.
Indicators 17, 18, 20, 21, 24, and 45 present data by race/ethnicity using CPS data. For more information on race/ethnicity, see supplemental note 1.
Indicators 1, 5, 21, and 45 use data from the October CPS and information from its supplemental questionnaire on enrollment in school.
Status Dropout Rate
Indicator 20 reports status dropout rates using data from the October CPS. The status dropout rate is one of a number of rates that are used to report high school dropout and completion behavior in the United States. Status dropout rates measure the percentage of individuals within a given age range who are not enrolled in high school and lack a high school credential, irrespective of when they dropped out. Status dropout rates are distinct from event dropout rates, which measure the proportion of students who drop out of high school in a given year; event dropout rates have been reported in a previous volume of The Condition of Education (NCES 2004-077, indicator 16) and are featured in the annual report Trends in High School Dropout and Completion Rates in the United States (see, for example, NCES 2011-012). For more information on measures of student persistence and progress featured in The Condition of Education 2011, see supplemental note 6.
The status dropout rate is the percentage of civilian, noninstitutionalized young people ages 16 through 24 who are not in high school and have not earned a high school credential (either a diploma or equivalency credential such as a General Educational Development [GED] certificate). The numerator of the status dropout rate for a given year is the number of individuals ages 16 through 24 who, as of October of that year, had not completed high school and were not currently enrolled in school. The denominator is the total number of individuals ages 16 through 24 who were in the United States in October of that year. Status dropout rates count as dropouts individuals who never attended school and immigrants who did not complete the equivalent of a high school education in their home country. The inclusion of these individuals is appropriate because the status dropout rate is designed to report the percentage of youth and young adults in the United States who lack what is now considered a basic level of education. However, the status dropout rate should not be used as a measure of the performance of U.S. schools because it counts as dropouts individuals who may have never attended a U.S. school.
The CPS October Supplement items used to identify status dropouts include (1) "Is...attending or enrolled in regular school?" and (2) "What is the highest level of school...completed or the highest degree...received?" (See the Educational Attainment section below for details on how the second question changed between 1972 and 1992.) Beginning in 1986, the Census Bureau instituted new editing procedures for cases with missing data on school enrollment (i.e., missing data relating to the first October Supplement item cited above). These changes were made in an effort to improve data quality. The effect of the editing changes was evaluated by applying both the earlier and revised editing procedures to the 1986 data. The changes resulted in an increase in the number of students enrolled in school and a slightly lowered status dropout rate (12.2 percent based on the earlier procedures and 12.1 percent based on the revised ones). The difference in the two rates is not statistically significant. While the change in the procedures occurred in 1986, the revised procedures are reflected in indicator 20 beginning with 1987 data.
Data from CPS questions on educational attainment are used in indicators 17, 21, and 24. From 1972 to 1991, two CPS questions provided data on the number of years of school completed: (1) "What is the highest grade or year of regular school...has ever attended?" and (2) "Did...complete that grade (year)?" An individual's educational attainment was considered to be his or her last fully completed year of school. Individuals who completed 12 years of schooling were deemed to be high school graduates, as were those who began but did not complete the first year of college. Respondents who completed 16 or more years of schooling were counted as college graduates.
Beginning in 1992, the CPS combined the two questions into the following question: "What is the highest level of school... completed or the highest degree...received?" This change means that some data collected before 1992 are not strictly comparable with data collected from 1992 onward, and that care must be taken when making comparisons across years. The revised question changed the response categories from "highest grade completed" to "highest level of schooling or degree completed." In the revised response categories, several of the lower grade levels are combined into a single summary category such as "1st, 2nd, 3rd, or 4th grades." Several categories are added, including "12th grade, no diploma"; "High school graduate, high school diploma, or the equivalent"; and "Some college but no degree." College degrees are now listed by level, allowing for a more precise description of educational attainment. The revised question emphasizes credentials received rather than the last grade level attended or completed. The new categories include the following:
High School Completion
The pre-1988 questions about educational attainment did not specifically consider high school equivalency certificates (i.e., GEDs). Consequently, an individual who attended 10th grade, dropped out without completing that grade, and subsequently received a high school equivalency credential would not have been counted as completing high school. The revised question allows for these individuals to be counted as high school completers. Since 1988, an additional question has also asked respondents if they have a high school diploma or the equivalent, such as a GED. People who respond "yes" are classified as high school completers. Before 1988, the number of individuals who earned a high school equivalency certificate was small compared to the number of high school graduates, so the subsequent increase caused by including equivalency certificate recipients in the total number of people counted as "high school completers" was small in the years immediately after the change was made.
Before 1992, the CPS considered individuals who completed 12th grade to be high school graduates. A revision in 1992 added the response category "12th grade, no diploma." Individuals who select this response are not counted as graduates. Historically, the number of individuals in this category has been small.
Based on the question used in 1992 and in subsequent surveys, the response for an individual who attended college for less than a full academic year would be "some college but no degree." Before 1992, the appropriate response would have been "attended first year of college and did not complete it," thereby excluding those individuals with 1–3 years of college from the calculation of the percentage of the population. With the revised question, such respondents are placed in the "some college but no degree" category. Thus, the percentage of individuals with some college might be larger than the percentage with 1–3 years of college, because "some college" includes those who have not completed an entire year of college, but "1–3 years of college" does not. Therefore, it is not appropriate to make comparisons between the percentage of those with "some college but no degree" (using the post-1991 question) and the percentage of those who completed "1–3 years of college" (using the two pre-1992 questions).
In The Condition of Education, the "some college" category for years preceding 1992 includes only the response "1–3 years of college." After 1991, the "some college" category included those who responded "some college but no degree"; "associate's degree in college, occupational/ vocational program"; and "associate's degree in college, academic program." The effect of this change to the "some college" category is indicated by the fact that in 1992, some 48.9 percent of 25- to 29-year-olds reported completing some college or more, compared with 45.3 percent in 1991 (see indicator 25 table 25-2, in NCES 2008-031). The 3.6 percentage point difference is statistically significant. Some of the increase between 1991 and 1992 may be the result of individuals who completed less than 1 year of postsecondary education responding differently to the "some college" category; that is, they included themselves in the category in 1992 but did not include themselves in the category in 1991.
Another potential difference in the "some college" category is how individuals who have completed a certificate or type of award other than a degree respond to the questions, introduced in 1992, about their educational attainment. Some may answer "some college, no degree"; others may indicate only high school completion; and still others may equate their certificate with one of the types of associate's degrees. No information is available on the tendencies of individuals with a postsecondary credential other than a bachelor's or higher degree to respond to the new attainment question introduced in 1992.
Some students attend college for 4 or more years without earning a bachelor's degree, so some researchers are concerned that the college completion rate, based on the pre-1992 category "4th year or higher of college completed," overstates the number of respondents with a bachelor's degree (or higher). In fact, however, the completion rates among those ages 25–29 in 1992 and 1993 were similar to the completion rates for 1990 and 1991, before the change in the question's wording. Thus, there appears to be good reason to conclude that the change has not affected the completion rates reported in The Condition of Education 2011.