The three major race categories distinguished in this report are white, Negro, and other races. Among persons of other races are American Indians, Japanese, Chinese, Filipinos, Koreans, Asian Indians, and Malayans. Negroes and persons of other races taken together constitute nonwhite persons. Persons of Mexican birth or descent who are not definitely Indian or other nonwhite race are classified as white. In addition to persons of Negro and of mixed Negro and white descent, the category Negro includes persons of mixed Indian and Negro descent unless the Indian ancestry very definitely predominates or unless the person is regarded as an Indian in the community.

In order to obtain data on Spanish- and Mexican/Americans for areas of the United States where most of them live, white persons (and white heads of households) of Spanish surname were distinguished separately in five Southwestern States (Arizona, California, Colorado, New Mexico, and Texas). In all other States, Puerto Rican persons (and heads of households) were identified. Puerto Rican comprise persons born in Puerto Rico and persons of native parentage with at least one parent born in Puerto Rico.

The data on employment status relate to the calendar week prior to the date on which the respondents filled their Household Questionnaires or were interviewed by enumerators. This week is not the same for all respondents because not all persons were enumerated during the same week.

Employed persons comprise all civilians 14 years old and over who were either (a) at work-those who did any work for pay or profit, or worked without pay for 15 hours or more on a family farm or in a family business; or (b) were with a job but not at work--those who did not work and were not looking for work but had a job or business from which they were temporarily absent because of bad weather, industrial dispute, vacation, illness, or other personal regions.

Persons are classified as unemployed if they were 14 years old and over and not at work but looking for work. A person is considered as looking for work not only if he actually tried to find work but also if he had made such efforts recently (i.e., within the past 60 days) and was awaiting the results of these efforts. Persons waiting to be called back to a job from which they had been laid off or furloughed are also counted as unemployed.

The civilian labor force includes all persons classified as employed or unemployed, as described above. The labor force also includes members of the Armed Forces (persons on active duty with the United States Army, Air Force, Navy, Marine Corps, or Coast Guard).Persons not in the labor force comprise all those 14 years old and over who are not classified as members of the labor force, including persons doing only incidental unpaid family work (less than 15 hours during the week).