The estimates in this report were obtained from the Current Population Survey (CPS), a national monthly sample survey of approximately 60,000 households that provides a wide range of information on the labor force, employment, and unemployment. Earnings data are collected from one-fourth of the CPS monthly sample. The survey is conducted for the U.S. Bureau of Labor Statistics (BLS) by the U.S. Census Bureau, using a scientifically selected national sample with coverage in all 50 States and the District of Columbia.
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Concepts and definitions
Civilian noninstitutional population. Included are persons 16 years of age and older residing in the 50 States and the District of Columbia who are not confined to institutions such as nursing homes and prisons, and who are not on active duty in the Armed Forces.
Employed persons. All persons who, during the reference week, (a) did any work at all (at least 1 hour) as paid employees, worked in their own business, profession, or on their own farm, or worked 15 hours or more as unpaid workers in an enterprise operated by a member of the family, and (b) all those who were not working but who had jobs or businesses from which they were temporarily absent because of vacation, illness, bad weather, childcare 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.
Unemployed persons. All persons who had no employment during the reference week, were available for work (except for temporary illness) and had made specific efforts to find employment sometime during the 4-week period ending with the reference week. Persons who were waiting to be recalled to a job from which they had been laid off need not have been looking for work to be classified as unemployed.
Duration of unemployment. This represents the length of time (through the current reference week) that persons classified as unemployed had been looking for work. For persons on layoff, duration of unemployment represents the number of full weeks they had been on layoff. Mean duration is the arithmetic average computed from single weeks of unemployment; median duration is the midpoint of a distribution of weeks of unemployment.
Reason for unemployment. Unemployment also is categorized according to the status of individuals at the time they began to look for work. The reasons for unemployment are divided into four major groups:
Labor force. This group comprises all persons classified as employed or unemployed in accordance with the criteria described above.
Unemployment rate. This represents the number of unemployed persons as a percent of the labor force.
Participation rate. This represents the proportion of the population that is in the labor force.
Employment-population ratio. This represents the proportion of the population that is employed.
Not in the labor force. Included in this group are all persons in the civilian noninstitutional population who are neither employed nor unemployed. The marginally attached are persons not in the labor force who wanted and were available for work and had looked for a job sometime in the prior 12 months (or since the end of their last job if they held one within the past 12 months). They were not counted as unemployed because they had not searched for work in the 4 weeks preceding the survey. Discouraged workers are a subset of the marginally attached who were not currently looking for work specifically because they believed no jobs were available for them.
Occupation, industry, and class of worker. This information for the employed applies to the job held in the reference week. Persons with two or more jobs are classified in the job at which they worked the greatest number of hours. The unemployed are classified according to their last job. Beginning in 2003, the occupational and industrial classification of CPS data is based on the 2002 Census Bureau occupational and industrial classification systems, which are derived from the 2000 Standard Occupational Classification (SOC) and the 2002 North American Industry Classification System (NAICS). (Consistent data are available back to 2000. Earlier data use a different classification system.)
White, black or African American, and Asian. These are terms used to describe the race of persons. Beginning in 2003, persons in these categories are those who selected that race group only. (Previously, persons identified a group as their main race.) Persons in the remaining race categories—American Indian or Alaska Native, Native Hawaiian or Other Pacific Islanders, and persons who selected more than one race category—are included in the estimates of total employment and unemployment but are not shown separately because the number of survey respondents is too small to develop estimates of sufficient quality. In the enumeration process, race is determined by the household respondent. More information on the 2003 changes in questions on race and Hispanic ethnicity is available on the BLS Web site at www.bls.gov/cps/rvcps03.pdf.
Hispanic or Latino ethnicity. This refers to persons who identified themselves in the enumeration process as being Spanish, Hispanic, or Latino. Persons whose ethnicity is identified as Hispanic or Latino may be of any race. More information on the 2003 changes in questions on race and Hispanic ethnicity is available online at www.bls.gov/cps/rvcps03.pdf.
Usual weekly earnings. Data represent earnings before taxes and other deductions, and include any overtime pay, commissions, or tips usually received (at the main job, in the case of multiple jobholders). Earnings reported on a basis other than weekly (for example, annual, monthly, hourly) are converted to weekly. The term “usual” is as perceived by the respondent. If the respondent asks for a definition of usual, interviewers are instructed to define the term as more than half the weeks worked during the past 4 or 5 months. Data refer to the sole or primary job of wage and salary workers (excluding all self-employed persons regardless of whether their businesses were incorporated).
Median earnings. These figures indicate the value that divides the earnings distribution into two equal parts, one part having values above the median and the other having values below the median. The medians shown in this publication are calculated by linear interpolation of the $50 centered interval within which each median falls.
Family. A family is defined as a group of two or more persons residing together who are related by birth, marriage, or adoption; all such persons are considered as members of one family. Families are classified either as marriedcouple families or as families maintained by women or men without spouses. A family maintained by a woman or a man is one in which the householder is never married, widowed, divorced, or separated.
Children. Data on children refer to one’s own children and include sons, daughters, stepchildren, and adopted children. Not included are nieces, nephews, grandchildren, other related children, and all unrelated children living in the household.Reliability of the estimates
Statistics based on the CPS are subject to both sampling and nonsampling error. When a sample, rather than an entire population, is surveyed, there is a chance that the sample estimates may differ from the “true” population values they represent. The exact difference, or sampling error, varies depending on the particular sample selected, and this variability is measured by the standard error of the estimate. There is about a 90percent chance, or level of confidence, that an estimate based on a sample will differ by no more than 1.6 standard errors from the “true” population value because of sampling error. BLS analyses are generally conducted at the 90percent level of confidence.
All other types of error are referred to as nonsampling error. Nonsampling error can occur for many reasons, including the failure to sample a segment of the population, inability to obtain information for all respondents in the sample, inability or unwillingness of respondents to provide correct information, and errors made in the collection or processing of data.
For a full discussion of the reliability of data from the CPS and information on estimating standard errors, see the Household Data section of “Explanatory Notes and Estimates of Error” in Employment and Earnings, on the BLS Web site at www.bls.gov/cps/eetech_methods.pdf.
Last Modified Date: December 4, 2009