Documentation: Census 1960 Tracts Only Set
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Publisher: U.S. Census Bureau
Document: School Enrollment (Volume II, Part V - Subject Reports)
citation:
U.S. Bureau of the Census. U.S. Census of Population: 1960. Subject Reports, School Enrollment. Final Report PC(2)-5A. U.S. Government Printing Office, Washington, D.C. 1964.
School Enrollment (Volume II, Part V - Subject Reports)
Definitions and Explanations
Some of the definitions used in 1960 differ from those used in 1950. These changes were made after consultation with users of census data in order to improve the statistics, even though it was recognized that comparability would be affected. The Definitions and Explanations should be interpreted in the context of the 1960 Censuses, in which data were collected by a combination of self-enumeration, direct interview, and observation by the enumerator.

The definitions below are consistent with the instructions given to the enumerator, is in all surveys, there were some failures to execute the instructions exactly. Through the forms distributed to households, the respondents were given explanations of some of the questions more uniformly than would have been given in direct interviews. Nevertheless, it was not feasible to give the full instructions to the respondents, and some erroneous replies have undoubtedly gone undetected.

More complete discussions of the definitions of population items are given in 1960 Census of Population, Volume I, Characteristics of the Population, Part 1, United States Summary, and in each of the State parts.
School Enrollment and Year of School in Which Enrolled
Definitions
The data on school enrollment were derived from answers to questions P14 and P16 on the Household Questionnaire, shown in the next column.
The answers to these questions were recorded for persons 5 to 34 years of age. The data on year of school in which enrolled were obtained by tabulating, for those who were enrolled, the responses to a question on the highest grade of regular school the person ever attended. (See definition of "Years of School Completed.")
School enrollment
Persons were included as enrolled in school if they were reported as attending or enrolled in a "regular" school or college at any time between February 1, 1960, and the time of enumeration. According to census definition, "regular" schooling refers to formal education obtained in public or private (denominational and nondenominational) kindergartens, elementary schools, high schools, colleges, universities, or professional schools, whether day or night school, and whether attendance was full time or part time; that is, "regular" schooling is that which may advance a person toward an elementary school certificate or high school diploma, or a college, university, or professional degree. Schooling that was not obtained in a regular school and schooling from a tutor or through correspondence courses were counted only if the credits obtained were regarded as transferable to a school in the regular school system. Persons who had been enrolled in a regular school since February 1, 1960, but who had not actually attended, for example, because of illness, were counted as enrolled in school.

Persons were excluded from the enrollment figures if the only schools they had been attending at any time since February 1, 1960, were not "regular" (unless courses taken at such schools could have been counted for credit at a regular school). Schooling which is generally regarded as not "regular" includes that which is given in nursery schools, in specialized vocational, trade, or business schools, in on-the-job training, and through correspondence courses.


Year of school in which enrolled
Persons who were enrolled were classified according to the level and year of school in which they were enrolled. The levels of school which have been separately identified in this report are kindergarten, elementary school, high school, and college. In most of the tables data are shown for specific grades or years within each level above kindergarten. Elementary school, as defined here, includes grades 1 to 8, and high school includes grades 9 to 12. At the time of enumeration, if a person was attending a junior high school, the equivalent grade in terms of 8 years of elementary school and 4 years of high school was recorded. The term college includes junior or community colleges, regular 4-year colleges, and graduate or professional schools. "Freshman" refers to a person enrolled in the first academic year of school, "sophomore" to a person in his second academic year, "junior" to a person enrolled in his third year, "senior" to a person in the fourth year, and "graduate or professional" to a person in the fifth or higher year of college.
Relative progress in school
In tables 3 to 7, enrolled persons are classified according to their relative progress in school, that is, according to whether the grade or year in which they were enrolled was below, at, or above the modal, or typical, grades for persons of their age. Inspection of age-grade relationships suggested that, for each age, two consecutive grades were almost equally representative of the mode. Tabulations of the categories "below mode for age," "mode for age and above mode for age" were made for single ages and then combined for publication into the age groupings shown in the tables.
The table below shows the basis used for classifying combinations of age and grade or year in which enrolled into the categories used in this report depicting relative progress in school.

Age Year in which enrolled
Below mode for age Mode for age Above mode for age
  Elementary: Elementary: Elementary:
7 None 1 and 2 3 or higher
8 1 2 and 3 4 or higher
9 2 or lower 3 and 4 5 or higher
10 3 or lower 4 and 5 6 or higher
11 4 or lower 5 and 6 7 or higher
12 5 or lower 6 and 7 8 or higher
      High school:
13 6 or lower 7 and 8 1 or higher
14 7 or lower Elem. 8 and H.S. 1 2 or higher
    High school:  
15 8 or lower 1 and 2 3 or higher
  High school:    
16 1 or lower 2 and 3 4 or higher
      College:
17 2 or lower 3 and 4 1 or higher
18 3 or lower H.S. 4 and College 1 2 or higher
19 4 or lower College 1 and 2 3 or higher


Enumeration of college students
All college students were enumerated in the 1960 and 1950 Censuses where they lived while attending college whereas, in earlier censuses, unmarried students generally were enumerated at their parental home. Since most colleges are located in nonfarm (primarily urban) areas, the rules for enumerating college students are especially relevant in the interpretation of enrollment data according to residence classifications. A study conducted in the Current Population Survey showed, however, that residence while attending college is the same under both the current and previous procedures for roughly one-half of the college students (e.g., for those who had set up their own households and those living with their parents while attending college); furthermore, only part of the one-half who would be classified at different residences would be counted in different regions or in different urban and rural residence areas.

Public or private school
Persons who were enrolled in school were classified as attending a public or private school. In General, a "public" school is defined as any school which is controlled and supported primarily by a local, State, or Federal governmental agency, whereas "private" schools are defined as schools which are controlled and supported by private persons or organizations, including those supported by a religious organization.
Uses and Limitations of the Data
The data in this report may be used to study social and economic factors associated with enrollment status of persons of school and college age, with relative progress in school as measured by the relationship between age and school grade, and with dropping out of school at particular school levels. One can analyze, for example, from tables 5 and 6, the relative importance of parents' education and family income on school enrollment and school progress of persons, holding constant their age, sex, color, type of residence, and attendance in a public or private school. From table 9, one can study demographic differences between college students who live in dormitories or fraternity or sorority houses and those who have other living arrangements while going to college. From table 14, one can examine the employment picture for school dropouts.

The data on school enrollment are limited to attendance in "regular" schools and colleges, as noted earlier, and thus exclude many persons who were enrolled at the time of the census in "special schools" (such as trade and business schools), in adult education programs, and in other "nonregular" schools. The number in such schools is substantial. For example, the October 1959 Current Population Survey reported 1.3 million persons 5 to 34 years old enrolled in "special" schools alone. In a survey in the 1958-59 school year undertaken by the U.S. Office of Education concerning public school adult education, 2.9 million persons were found to be participating in such classes for adults. According to a CPS survey two years earlier, sponsored by the U.S. Office of Education, an estimated 8 million persons were attending formal public or private classes that did not provide them with credit toward a regular diploma or degree; still other persons were taking less formal or informal instruction of one type or another that might be construed as schooling, in a broad sense.

Many types of "nonregular" (formal and informal) schooling and training may contribute substantially to an individual's knowledge and skills. The statistics on school enrollment in the census are restricted to progress in "regular" schools for several reasons: (1) nearly all persons in the country are required to attend "regular" schools and pursue fairly standardized courses of basic study (2) "Regular" schools tend to be graded schools, with the result that a grade continuum for years of school in which enrolled can be shown and statistical comparisons can be affected (3) "Nonregular" types of schooling are varied and are difficult to define and to classify in enumeration.
Comparability
Earlier census data
The corresponding question on schooling in the 1910, 1920, and 1930 Censuses Generally applied to a somewhat longer period, the period since the preceding September 1. The 1920 Census was taken in January, however, whereas the 1910 and later censuses were taken in April. In censuses prior to 1940, the question was not restricted as to the kind of school the person was attending. In 1940, the question referred to the period since the preceding March 1. There were indications following that census that in some areas the schools closed early (i.e., before March 1) for such reasons as lack of funds, flood conditions, or crop sowing. For such areas, the enrollment rates would, therefore, have been relatively low. In order to insure more complete comparability among areas, it was considered advisable in 1950 to change the reference period to that between February 1 (the usual date for beginning the second semester) and the time of enumeration. The corresponding reference period was used in 1960.

In 1950, separate questions on highest grade attended and completion of the grade were used for the first time to get data on Years of School Completed instead of the single question on highest grade completed used in 1940. This change probably helped to reduce overreporting of grade in which enrolled. In 1940, the responses to the question on highest grade of school completed were combined with the responses to the question on enrollment, and enrolled persons were assumed to have been enrolled in the grade above the one they had completed. Since there are some indications that many persons in 1960 reported the highest grade attended instead of the highest one completed, there probably was a significant amount of overreporting of year of school in which enrolled in that census.

Also, in 1950, for the first time in a decennial census, kindergarten enrollment was separately identified, but the number of children enrolled in kindergarten was not included with the 1950 statistics on enrollment in regular schools. By 1960, kindergartens had become widely accepted and more than half of the children of kindergarten age not enrolled in elementary school were enrolled in kindergarten. Consequently, in the 1960 statistics, kindergarten enrollment was included with the regular enrollment figures.

The age range for which enrollment data have been asked has varied for the several censuses. Information on enrollment was recorded for persons of all ages in 1910 through 1940, for persons 5 to 29 years old in 1950, and for those 5 to 34 years old in 1960. Most of the published enrollment figures related, however, to ages 6 to 20 in 1910, 7 to 20 in 1920, 5 to 20 in 1930, 5 to 24 in 1940, 5 to 29 in 1950, and 5 to 34 in 1960. The enrollment statistics at the older ages reported in 1930 and 1940 were regarded as of poor quality and as relating mostly to enrollment in other than regular schools. The extended age coverage for the published enrollment data in the recent censuses reflects the increasing number of persons in their late 20's and early 30's who are attending regular colleges and universities.

In 1960, as in prior censuses, persons for whom there was no report on school enrollment were allocated as either enrolled or not enrolled. In both 1940 and 1950, the Editing rules were determined largely on the basis of information on ages of compulsory school attendance as compiled by the U.S. Office of Education. Additional information used in Editing included other items on the schedule and results of Current Population Surveys showing the percent enrolled at various age groups. In General, in 1940 and 1950, persons 5 through 17 years of age not reporting on school enrollment were treated as enrolled, whereas those over 17 years old were considered not enrolled. The General scheme used in eliminating non- responses in 1960 is discussed in the section below on "Collection and processing of data."
Current Population Survey
Comparisons between the April 1960 Census and the Current Population Survey taken in October 1959, the beginning of the same school year, showed that the figures on public school enrollment in kindergarten through the 12th grade were in close agreement. There were 35.3 million persons enrolled according to the census, compared with 34.9 million according to the October 1959 survey. College enrollment was about 12 percent lower in the census than in the survey. An inquiry made of a sample of colleges and universities showed, however, that nearly all of the differences could be accounted for by attrition in college enrollment between the fall and spring, rather than from undercounting of college students in the census.
Enrollment by age differed somewhat between the two sources. Most of this difference could be explained by shifts in age distribution between the fall and spring; for example, the enrollment rate for persons 18 and 19 years old was higher in the census because many high school seniors who were 17 and 18 years old in October became 18 or 19 in April, before they completed high school.
Data from other sources
Data on school enrollment are also collected and published by other Federal, State, and local governmental agencies, and by independent research organizations. This information is generally obtained from reports of school systems and institutions of higher learning, and from other surveys and censuses. These data are only roughly comparable with data collected by the Bureau of the Census by household canvassing, however, because of differences in definitions, subject matter covered, time references, and enumeration methods. To illustrate, the enrollment figures from the census tend to be lower than those in the Biennial Survey of Education, conducted by the U.S. Office of Education, largely because the census data refer to a shorter time period and count a person only once, although he may have attended more than one school during the reporting period. In the biennial survey, some persons are included in the enrollment figures more than once, such as those enrolled in both public and private schools and those enrolled in two different States at any time during the school year. The census data also are unlike enrollment data from other sources in that they are a unique source of national information about the characteristics of enrolled persons and their families.
Quality of the Data
Information on the quality of data on School Enrollment and Year of School in Which Enrolled is available from two sources: (a) Reports of nonresponse rates; and (b) findings from the Evaluation and Research Program of the 1960 Census. This program included a study entitled "The Accuracy of Population Characteristics as Measured by Intensive Reinterview," based on a sample of census respondents. In this study (Study EP-10), measures of response error were developed with respect to selected items of information by comparing and reconciling the responses obtained in the reinterview with the corresponding census entries.

About 8 percent of the population 5 to 34 years old did not report on school enrollment in the 1960 Census. Nonresponse rates were highest at the older school and college ages, presumably because many persons who had already left school did not think it was necessary for them to answer the question. Of those reported as enrolled, 3 percent did not report the year in which the person was enrolled and about 6 percent did not respond to the question on whether the enrollee was in a public or private school or college. Nonresponse rates on enrollment items were higher for nonwhites than whites; they were generally higher in urban than in rural areas although these differences were small.

The results of Study EP-10 suggest that there was little misreporting of school enrollment and of the type of school (public or private) in which persons were enrolled. In terms of year in which enrolled, about 2.0 percent of enrolled persons reported a higher grade in the census than in the evaluation study whereas 0.6 percent reported a lower grade in the census; the net result was that l.!f percent reported a higher grade in the census.

The results of the 1960 evaluation study are not entirely comparable with those of the 1950 Post- Enumeration Survey. In considering comparative results, it should be noted that reported differences in quality may, in part, arise from improvement in procedures in the 1960 evaluation study, changes in accuracy between the 1960 and 1950 Censuses, or both. For a more comprehensive report of the results of the evaluation studies, see the 1960 Census reports in the Evaluation and Research Program Series and Bureau of the Census, Technical Paper No. 4, The Post-Enumeration Survey: 1950.
Urban-Rural Residence
In General, the urban population comprises all persons living in urbanized areas and in places of 2,500 inhabitants or more outside urbanized areas. More specifically, according to the definition adopted for use in the 1960 Census, the urban population comprises all persons living in (a) places of 2,500 inhabitants or more incorporated as cities, boroughs, villages, and towns (except towns in New England, New York, and Wisconsin); (b) the densely settled urban fringe, whether incorporated or unincorporated, of urbanized areas; (c) towns in New England and townships in New Jersey and Pennsylvania which contain no incorporated municipalities as subdivisions and have either 25,000 inhabitants or more or a population of 2,500 to 25,000 and a density of 1,500 persons or more per square mile; (d) counties in States other than the New England States, New Jersey, and Pennsylvania that have no incorporated municipalities within their boundaries and have a density of 1,500 persons or more per square mile; and (e) unincorporated places of 2,500 inhabitants or more. The population not classified as urban constitutes the rural population.
Farm-Nonfarm Residence
The rural population is subdivided into the rural- farm population, which comprises all rural residents living on farms, and the rural-nonfarm population, which comprises the remaining rural population. In the 1960 Census, the farm population consists of persons living in rural territory on places of 10 or more acres from which sales of farm products amounted to $50 or more in 1959 or on places of less than 10 acres from which sales of farm products amounted to $250 or more in 1959. All persons living in group quarters are classified as nonfarm except the relatively few living in workers' quarters (including quarters for migratory agricultural workers) that are located on a farm or ranch.
Urbanized Area
An Urbanized Area contains at least one city of 50,000 inhabitants or more in 1960 and the surrounding closely settled incorporated places and unincorporated areas that meet certain criteria relating to population density or land use. An Urbanized Area may be thought of as divided into the central city, or cities, and the remainder of the area, or the urban fringe. All persons residing in an Urbanized Area are included in the urban population.
The age classification is based on the age of the person in completed years as of April 1, 1960, as determined from the reply to a question on month and year of birth.
Race and Color
The term "color" refers to the division of population into two groups, white and nonwhite. The color group designated as "nonwhite" consists of such races as the Negro, American Indian, Japanese, Chinese, Filipino, Korean, Hawaiian, Asian Indian, Eskimo, Aleut, and Malayan races. Persons of Mexican birth or ancestry who are not definitely of Indian or other nonwhite race are classified as white.
In addition to persons of Negro and of mixed Negro and white descent, this classification includes persons of mixed Indian and Negro descent, unless the Indian ancestry predominates or unless the individual is regarded as an Indian in the community.
American Indian
In addition to full-blooded Indians, persons of mixed white and Indian blood are included if the proportion of Indian blood is one- fourth or more, or if they are regarded as Indian in the community. Indians living in Indian territory or on reservations were not included in the population until 1890.
Other races
Separate statistics are given in this report for Japanese and Chinese. The category "other races" includes Filipinos, Koreans, Hawaiians, Asian Indians, Eskimos, Aleuts, Malayans, etc.
Mixed parentage
Persons of mixed racial parentage are classified according to the race of the nonwhite parent, and mixtures of nonwhite races are classified according to the race of the father, with the special exceptions noted above.
Nativity and Parentage
Native
This category comprises persons born in the United States, the Commonwealth of Puerto Rico, or a possession of the United States; persons born in a foreign country or at sea who have at least one native American parents and persons whose place of birth was not reported and whose census report contained no contradictory information, such as an entry of a language spoken prior to coming to the United States.
Foreign born
This category includes all persons not classified as native.
Native of native parentage
This category consists of native persons both of whose parents are also natives of the United States.
Native of foreign or mixed parentage
This category includes native persons one or both of whose parents are foreign born.
Foreign stock
This category includes foreign-born persons and native persons of foreign or mixed parentage.
Region of Origin of the Foreign Stock
Persons of foreign stock are classified in the 1960 Census according to their country of origin-country of birth for the foreign born and parents' country of birth for the native of foreign or mixed parentage. Natives of foreign parentage whose parents were born in different countries are classified according to the country of birth of the father. Natives of mixed parentage are classified according to the country of birth of the foreign-born parent. The classification by country of origin is based on international boundaries as recognized by the United States Government on April 1, 1960, although there may have been some deviation from the rules where respondents were unaware of changes in boundaries or jurisdiction.

In this report, information on country of origin is shown for one segment of the foreign stock-native white persons of foreign or mixed parentage-and is in terms of General regions rather than individual countries. The classification embraces four regions, or groups of countries, representing three groups of European stock and a fourth group for the remaining areas of the world. A list of the countries included in these groupings is shown in the PC(2)-5B report, Educational Attainment.
Years of School Completed
The data on Years of School Completed were derived from the answers to the two questions: (a) "What is the highest grade (or year) of regular school he has ever attended?" and (b) "Did he finish this grade (or year)?" Enumerators were instructed to obtain the approximate equivalent grade in the American school system for persons whose highest grade of attendance was in a foreign school system, whose highest level of attendance was in an ungraded school, whose highest level of schooling was measured by "readers," or whose training by a tutor was regarded as qualifying under the "regular" school definition. Persons were to answer "No" to the second question if they were attending school, had completed only part of a grade before they dropped out, or failed to pass the last grade attended.

The number in each category of highest grade of school completed represents the combination of (a) persons who reported that they had attended the indicated grade and finished it, and (b) those who had attended the next higher grade but had not finished it.
Marital Status
This classification refers to the Marital Status of the person at the time of enumeration. Persons classified as "married" comprise, therefore, both those who have been married only once and those who remarried after having been widowed or divorced. Persons reported as separated (either legally separated or otherwise absent from the spouse because of marital discord) are classified as a subcategory of married persons. The enumerators were instructed to report persons in common-law marriages as married and persons whose only marriage had been annulled as single.

The number of married men may be different from the number of married women for an area because of the absence of husbands or wives from the country, because the husband and wife have different places or residence, because of the methods used to inflate the sample data, or for other reasons.
A married person with "spouse present" is a man or woman whose spouse was enumerated as a member of the same household even though he or she may have been temporarily absent on business or vacation, visiting, in a hospital, etc., at the time of enumeration.
Household, Group Quarters, and Relationship to Head of Household
A household consists of all the persons who occupy a housing unit. A house, an apartment or other group of rooms, or a single room, is regarded as a housing unit when it is occupied or intended for occupancy as separate living quarters; that is, when the occupants do not live and eat with any other persons in the structure and there is either (1) direct access from the outside or through a common hall or (2) a kitchen or cooking equipment for the exclusive use of the occupants.
All persons who are not members of households are regarded as living in group quarters. Group quarters are living arrangements for institutional inmates or for other groups containing five or more persons unrelated to the person in charge. Most of the persons in group quarters live in rooming houses, college dormitories, military barracks, or institutions. Inmates of institutions are persons for whom care or custody is provided in such places as homes for delinquent or dependent children; homes and schools for the mentally or physically handicapped; places providing specialized medical care for persons with mental disorders, tuberculosis, or other chronic disease; nursing and domiciliary homes for the aged and dependent; and prisons and jails.

For persons in households, several categories of relationship to head of household are recognized in this report:

1. The head of the household is the member reported as the head by the household respondent. However, if a married woman living with her husband is reported as the head, her husband is classified as the head for the purpose of census tabulations.
2. The wife of a head of a household is a woman married to and living with a household head. This category includes women in common-law marriages as well as women in formal marriages.
Family, Own Child and Unrelated Individual
A family consists of two or more persons in the same household who are related to each other by blood, marriage, or adoption; all persons living in one household who are related to each other are regarded as one family. In a primary family, the head of the family is the head of a household. Other families are secondary families. A "husband-wife" family is a family in which the head and his wife are enumerated as members of the same household.

An own child is defined here as a single (never married) son, daughter, stepchild, or adopted child of the person in question.

An unrelated individual is (1) a member of a household who is living entirely alone or with one or more persons all of whom are not related to him, or (2) a person living in group quarters who is not an inmate of an institution. A head of a household living alone or with nonrelatives only is a primary individual. An unrelated individual who is not a household head is a secondary individual.
Employment Status
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 reasons.

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).
Occupation
The data on occupation in this report are for employed persons and refer to the job held during the week for which employment status was reported. For persons employed at two or more jobs, the data refer to the job at which the person worked the greatest number of hours. The occupation statistics presented here are based on the detailed systems developed for the 1960 Census; see 1960 Census of Population, Classified Index of Occupations and Industries, U.S. Government Printing Office, Washington, D.C., 1960.

"White collar workers" include the professional, managerial (nonfarm), clerical, and sales major occupation groups; "manual and service workers" include the craftsmen, operative, service, and nonfarm laborer groups and persons with occupation not reported; and "farm workers" include the farmer and farm laborer groups.
Work Experience In 1959
Persons who "worked in 1959" include those who did any work for pay or profit (including paid vacation and sick leave) or worked without pay on a family farm or in a family business. Active service In the Armed Forces is also included.
Income In 1959
Information on income for the calendar year 1959 was requested from all persons lb years old and over in the sample. "Total income" is the sum of amounts reported separately for wage or salary income, self- employment income, and other income. Wage or salary income is defined as the total money earnings received for work performed as an employee. It represents the amount received before deductions for personal income taxes, Social Security, bond purchases, union dues, etc. Self-employment income is defined as net money income gross receipts minus operating expenses) from a business, farm, or professional enterprise in which the person was engaged on his own account. Earnings are obtained by summing wage or salary income and self-employment income. Other income includes money income received from such sources as net rents, interest, dividends, Social Security benefits, pensions, veterans' payments, unemployment insurance, and public assistance or other governmental payments, and periodic receipts from insurance policies or annuities. Not included as income are money received from the sale of property (unless the recipient was engaged in the business of selling such property), the value of income "in kind," withdrawals of bank deposits, money borrowed, tax refunds, and gifts and lump-sum inheritances or insurance payments.

In the statistics on family income, the combined incomes of all members of each family are treated as a single amount. Although the time period covered by the income statistics is the calendar year 1959, the composition of families refers to the time of enumeration. For most of the families, however, the income reported was received by persons who were members of the family throughout 1959.