GENERAL

This report presents statistics by census tracts on population and housing characteristics enumerated in the 1960 Censuses of Population and Housing, taken as of April 1, 1960. The population items are: Race and color, nativity and parentage, foreign stock and country of origin, age, relationship to head of household, marital status, married couples and families, school enrollment, years of school completed, residence in 1955, income in 1959, employment status, occupation, industry, class of worker, place of work, and means of transportation to work. The housing items are: Tenure of housing unit, color of occupants, vacancy status, number of persons in the unit, persons per room, year moved into the unit, number of units in structure, year structure built, basement in structure, number of rooms, condition and plumbing, number of bathrooms, heating equipment, automobiles available, value of property, contract rent, and gross rent. Some of these items were enumerated on a complete-count basis and others were collected for a sample of persons and housing units (see section on "Sample design").

The 1960 Censuses contained several innovations. One of them was the use of forms which household members were asked to complete the Advance Census Report form for the completecount items and, in the more populous sections of the country, the Household Questionnaire for the sample items. Other innovations included the wider use of sampling and the extensive use of the electronic computer and related equipment to process the data and produce the final tables. These innovations were designed primarily to improve the quality of the statistics and to reduce the time required to collect and publish the data; at the same time, they have introduced an element of difference between the 1960 statistics and those of earlier censuses. Innovations are discussed in later sections of this report and in more detail in 1960 Census of Population, Volume I, Characteristics of the Population, and in 1960 Census of Housing, Volume I, States and Small Areas.

Definition of census tract.-Census tracts are small areas into which large cities and adjacent areas have been divided for statistical purposes. Tract boundaries were established cooperatively by a local committee and the Bureau of the Census, and were generally designed to be relatively uniform with respect to population characteristics, economic status, and living conditions. The average tract has about 4,000 residents. Tract boundaries are established with the intention of being maintained over a long time so that comparisons may be made from census to census.

In the decennial censuses, the Bureau of the Census tabulates population and housing information for each census tract. The practice of local agencies to tabulate locally collected data by tracts has increased the value of census tract data in many areas. Historical background.-The concept of census tracts was originated by the late Dr. Walter Laidlaw in New York City in 1906. He was convinced of the need for data for homogeneous subdivisions of cities as a basis for studying neighborhoods smaller than

boroughs or wards. At his request, the Bureau of the Census tabulated census tract data from the 1910 Census for New York and seven other cities with a population of over 500,000. Tract data were again tabulated for the same 8 cities in 1920, and in 1930 this number was increased to 18. In 1940, tract data were tabulated for 60 cities, some with adjacent tracted areas; and, beginning in 1940, housing data were added to the population data in the tract reports. In 1950, final reports were published for 64 tracted areas, many of which included statistics for two or more large cities. By 1960, the program had expanded to include reports for 180 tracted areas (of which 3 are in Puerto Rico).

Much of the credit for the growing interest in tract data belongs to the late Howard Whipple Green of Cleveland. He aroused the interest of research workers in numerous cities in the potential usefulness of tract statistics for the analysis of sociological, marketing, and administrative problems. In his capacity as Chairman of the Committee on Census Enumeration Areas of the American Statistical Association for 25 years, he accepted the responsibility for appointing a Census Tract Key Person in each area where tracts were established, for providing guidance on delineating and maintaining census tracts, and for maintaining a census tract library. These duties were assumed by the Bureau of the Census in 1955. For a further discussion of census tract data and their uses, see U.S. Bureau of the Census, Census Tract Manual, Fourth Edition, 1958, Government Printing Office, Washington 25, D.C.

Description of tables.-Tables P-1, P-2, and P-3 present population characteristics and tables H-1 and H-2 present housing characteristics for all tracts. Tables P-4 and H-3 show population and housing data for nonwhite persons. Tables P-5 and H-4 show population and housing data for white persons with Spanish surname in the tracted areas of Arizona, California, Colorado, New Mexico, and Texas. In all other States, tables P-5 and H-4 show population and housing data for persons of Puerto Rican birth or parentage. Tables P-4, P–5, H−3, and H-4 are presented only when there are at least 5,000 persons in the particular group in the standard metropolitan statistical area. Furthermore, data are shown in tables P-4 and P-5 only for tracts with 400 or more of these persons; in table H-3 for tracts containing 100 or more housing units with nonwhite persons as household heads; and in table H-4 for tracts with 400 or more units with heads that are Puerto Ricans or white persons with Spanish surname. In table H-3, only data from the 100-percent tabulations are shown for tracts with fewer than 400 nonwhite occupied units.

In tables P-4, P-5, H-3, and H-4, a tract may appear in the population tables but not in the housing tables, and vice versa, depending on whether or not the criteria for presentation are met. The "total" columns (for the SMSA, counties, cities, etc.) include statistics for those tracts which are omitted from the tables because they have fewer than the specified number of persons or housing units. These totals, therefore, are not necessarily the sum of the figures for the tracts that are shown in the tables. Moreover, in the "total" columns of tables P-4, P-5, H-3, and H-4, the

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number of persons or housing units is shown but data on characteristics are suppressed if there are fewer than the specified number of cases.

In order to avoid disclosure of information for individual persons or housing units, characteristics other than value and rent are not shown for a tract if the total number of persons or housing units in the tract is four or fewer. Data on value of property are not shown for a tract if there are four or fewer owner-occupied housing units of the type for which value of property is presented. Likewise, data on rent are not shown if there are four or fewer renter-occupied nonfarm housing units. However, the data on characteristics not shown for such tracts are included in the totals for the city or other area.

Medians are not shown where the base is smaller than the minimum required. For items tabulated on a complete-count basis, the median is not shown if the base is less than 50 persons or housing units; for items tabulated from a sample, the median is suppressed if the base is less than 200 persons or housing units. Leaders (...) in a data column indicate that either there are no cases in the category or the data are suppressed as described above. In addition, in table H-3, data for items based on a sample are suppressed in tracts with fewer than 400 housing units with nonwhite heads; and in table H-2, data on automobiles are suppressed in individual tracts where the information was based wholly or partly on a 5-percent sample (see table A in the section on "Sample design").

Description of tracted area. The map included in this report identifies the boundaries of the area for which the tract statistics are presented. The map also identifies the location and number of each tract and, when appropriate, the limits of cities, townships, counties, or other subdivisions of the tracted area. If only a part of the standard metropolitan statistical area (SMSA) is tracted, the map shows only the tracted portion; in the tables, however, totals are shown for the entire SMSA.

Most of the tracted areas constitute entire SMSA's. Some tracted areas, however, consist of only a part of the SMSA or only the central city. A few include all or part of the SMSA plus an adjoining area outside it, and two (Middlesex and Somerset Counties, New Jersey) comprise counties which were within an SMSA when they were divided into census tracts but were removed from the SMSA as a result of a change in boundary definitions.

Within each table, the first set of columns presents totals for the SMSA, the component counties, cities and other urban plaçes having a population of 25,000 or more, and "balances" of the SMSA. Following the totals, data for individual tracts are shown for the component parts which are tracted. If the report presents data for tracts adjacent to the SMSA, they are shown after the tracts within the SMSA. (Unincorporated places are designated by the letter "U" following the place name, and urban towns and townships by "UT".)

Statistics for the central county (the county containing the central city of the SMSA) are presented ahead of those for the other counties in the area. Within a county, any central city is first, followed by other cities and urban places, arranged alphabetically, and finally the balance of the county. If the balance of the county is only partially tracted, it is shown in two partstracted balance and untracted balance.

When a tract crosses the boundary of an urban place of 25,000 inhabitants or more, statistics for the portion of the tract which lies inside the city are shown with the figures for the city; statistics for the remainder of the tract are shown in the tracted balance. The totals for each of these tracts appear at the end of the table. Separate statistics on nonwhites, Puerto Ricans, and white persons of Spanish surname are shown for the tract total and for each part of a split tract which qualifies under the criteria for presentation of such data.

Tracts are generally numbered in a consecutive series, with

as possible, the numbers are consecutive within each city, community, township, and the like. A tract number followed by the symbol "CV" indicates that the statistics are for crews of vessels only; these statistics are not included in the statistics for the rest of the tract. In 1950, data for crews of vessels were included in the data for the entire tract.

Comparability from census to census.-One of the objectives of providing statistics by tracts is to preserve comparability. Keeping tract boundaries unchanged from census to census makes possible the study of changes in social and economic characteristics of neighborhoods. Though the character of the people and land use within a tract may change with time, the principle of permanent boundaries is ordinarily given priority over the principle of internal homogeneity. Major revisions in the tract plan for a whole city or county are, therefore, rarely made. There are, nonetheless, several situations where boundaries of individual tracts are changed. For example, it is sometimes necessary to change the boundaries of tracts to add small areas annexed to a city. Similarly, changes in tract boundaries occur when territory is detached from a city or separately incorporated. Changes may also occur in physical features that are used as tract boundaries, such as street or highway relocations. The census tract limits are changed to conform with the revised feature or to follow another nearby visible feature. Census tracts with very large increases in population are subdivided into two or more smaller tracts. On the other hand, a re-examination of the existing tract boundaries may result in modifications of boundaries to provide larger or more homogeneous units.

A number of population and housing characteristics which were not reported for 1950 are included in this report. Population items shown in the 1960 tract reports, but not in the 1950 reports, are school enrollment, industry, means of transportation to work, and place of work. Housing items added in 1960 are number of rooms, bathrooms, heating equipment, year moved into unit, automobiles available, basement in structure, and gross rent. A few housing items which appeared in the 1950 tabulations for census tracts have been omitted from the 1960 reports, either because no information was collected in the 1960 Census or because alternative data were considered more valuable for the

program by users of tract statistics. Items omitted are type of structure, refrigeration equipment, television, and heating fuel.

In addition to showing data on new items, the 1960 tract reports include more detail on many of the 1950 items. For example, data on marital status are shown separately for the nonwhite population in 1960, whereas in 1950 these data were shown only for the total population; and the detail about persons per room has been expanded to show four categories rather than just one. Furthermore, there were some changes in concepts and procedures. These changes may affect comparisons between the 1960 and 1950 statistics.

Availability of unpublished data.-Photocopies of tabulated but unpublished data for census tracts can be provided at cost. For population items, the tabulated material covers farm-nonfarm residence of the rural population, characteristics of persons 14 years old and over not in the labor force, class of worker of farm workers, and greater detail than shown here on place of residence in 1955 and place of work. Unpublished housing data cover farmnonfarm residence and tenure of rural housing units, type of trailers, source of water, method of sewage disposal, year structure was built and year moved into the unit for owner-occupied units, and number of stories and presence of elevator in the structure. For all tracts, data are available for nonwhites on household relationship, condition and plumbing facilities of the housing unit, number of persons and number of rooms in the unit, and persons per room. For tracts with a specified number of nonwhites, the unpublished tabulations include the greater detail for nonwhites on place of residence in 1955 and farm-nonfarm residence of rural

Puerto Ricans or white persons with Spanish surname, they include year moved into unit for these groups.

Requests for unpublished statistics should be addressed to the Chief, Population Division, or the Chief, Housing Division, Bureau of the Census, Washington 25, D.C.

Median. The median is presented in connection with the data on age, years of school completed, income, number of persons, number of rooms, and value or rent of the unit. The median is the theoretical value which divides the distribution into two equal parts-one-half the cases falling below this value and one-half the cases exceeding this value.

A plus (+) or minus (-) sign after the median indicates that the median is above or below that number. For example, a median of "$5,000-" for value of property indicates that the median fell in the interval "less than $5,000" and was not computed from the data as tabulated.

Standard metropolitan statistical area (SMSA).-Except in New England, an SMSA is a county or group of contiguous counties which contains at least one city of 50,000 inhabitants or more, or "twin cities" with a combined population of at least 50,000. In addition to the county, or counties, containing such a city or cities, contiguous counties are included in an SMSA if, according to certain criteria, they are essentially metropolitan in character and are socially and economically integrated with the central city. In New England, SMSA's consist of towns and cities, rather than counties.

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. Some of the information required for identifying separate housing units was obtained by the enumerator as part of the procedure for securing complete coverage of all living quarters. Furthermore, the condition of a unit was determined solely by the enumerator through his observation. The remaining items were completed by self-enumeration, or by direct interview when the household member did not complete the self-enumeration forms.

The definitions below are consistent with the instructions given to the enumerator. As 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 the reports in Series PC(1)-B (for completecount items) and in Series PC(1)-C (for sample items). These reports constitute chapters B and C of each State part of 1960 Census of Population, Volume I, Characteristics of the Population. Likewise, more complete discussions of housing items are given in 1960 Census of Housing, Volume I, States and Small Areas.

POPULATION CHARACTERISTICS

Race and color.-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 of Indian or other nonwhite race are classified as 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.

Nativity and parentage.-The category "native" 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 parent; 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. The category "foreign born" comprises all persons not classified as native.

Native persons of native parentage comprise native persons, both of whose parents are also natives of the United States. Native persons of foreign or mixed parentage comprise native persons, one or both of whose parents are foreign born.

Persons of Spanish surname and Puerto Ricans.-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 Ricans comprise persons born in Puerto Rico and persons of native parentage with at least one parent born in Puerto Rico.

Foreign stock and country of origin.-The foreign-born population is combined with the native population of foreign or mixed parentage in a single category termed "foreign stock." In this report, persons of foreign stock are classified according to their country of origin. 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.

Age. 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.

Household, group quarters, and relationship to head of household. A household consists of all the persons who occupy a housing unit (see definition of housing unit in section below on "Living quarters"). The population per household is obtained by dividing the population in households by the number of households. The population per household is not shown for nonwhite persons in tracts where most of the nonwhite persons live in the homes of white persons as "nonrelatives"; these persons perform domestic service work, live as lodgers while attending college, or have some other special living arrangement.

All persons who are not members of households are classified as living in group quarters. 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; prisons; and jails.

For persons in households, five 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

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.

3. The children under 18 of the household head are the head's sons and daughters under 18 years old and also his stepchildren and adopted children of this age group.

4. "Other relative of head," in this report, includes all persons who are related to the head of the household by blood, marriage, or adoption except those in the categories "wife of head" and "children under 18 of head."

5. A nonrelative of the head is any member of the household who is not related to the household head by blood, marriage, or adoption. Lodgers, partners, resident employees, wards, and foster children are included in this category.

Marital status.-This classification refers to the person's marital status 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. The enumerators were instructed to report persons in common-law marriages as married and persons whose only marriage had been annulled as single. Separated persons are included in the count of married persons.

Married couple, family, and unrelated individual.-In 1960, a married couple is defined as a husband and wife enumerated as members of the same household. Data are not available for the very small number of married couples living as inmates of institutions or as other members of group quarters. A married couple with own household is a married couple in which the husband is a household head.

An "own child" of a married couple is defined as a single (never married) son, daughter, stepchild, or adopted child of the couple. Persons under 18 living with both parents include stepchildren and adopted children as well as sons and daughters born to the couple.

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. An unrelated individual is a member of a household who is not related to anyone else in the household, or is a person living in group quarters who is not an inmate of an institution. Α head of a household living alone or with nonrelatives only is a primary individual.

School enrollment.-School enrollment is shown for persons 5 to 34 years old. 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. 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. 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.

Elementary school, as defined here, includes grades 1 to 8, and high school includes grades 9 to 12. College includes junior or community colleges, regular 4-year colleges, and graduate or professional schools. In general, a "public" school is defined as any school which is controlled and supported primarily by a local, State, or Federal agency. All other schools are "private" schools.

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

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.

Residence in 1955.-Residence on April 1, 1955, is the usual place of residence five years prior to the enumeration. The category "same house as in 1960" includes all persons 5 years old and over who were reported as living in the same house on the date of enumeration in 1960 and five years prior to the enumeration. Included in the group are persons who had never moved during the five years as well as those who had moved but by 1960 had returned to their 1955 residence. The category "different house in the U.S." includes persons who, on April 1, 1955, lived in the United States in a different house from the one they occupied on April 1, 1960. For tracted areas in SMSA's, persons in this category are subdivided into several groups according to their 1955 residence, viz., "central city of this SMSA," "other part of this SMSA," and "outside this SMSA." The category "abroad" includes those with residence in 1955 in a foreign country, in the Commonwealth of Puerto Rico, or in a possession of the United States. For tracted areas in Somerset and Middlesex Counties, New Jersey, the categories of residence in 1955 for those living in a different house in the United States are: "Same county," "different county, same State," and "different county, different State."

Income in 1959.-Information on income for the calendar year 1959 was requested from all persons 14 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. 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. 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. 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, industry, and class of worker.-The data on these three subjects 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 and industry statistics presented here are based on the detailed systems developed for the 1960 Census; see 1960 Classified Index of Occupations and Industries, Government Printing Office, Washington 25, D.C.

Place of work and means of transportation to work."-Place of work refers to the geographic location in which civilians at work and Armed Forces personnel not on leave, sick, etc., carried out their occupational or job activities. These locations comprise, for the purposes of this report, central cities, other selected cities, remainders of central counties, and each of the additional counties within the standard metropolitan statistical area (SMSA). In the reports for Somerset and Middlesex Counties in New Jersey, however, the distributions are shown only within these respective counties. In all cases, 13 specific places of work are available in unpublished tabulations for each tract.

Persons with more than one job were asked to report on the job at which they worked the greatest number of hours. If salesmen, deliverymen, and others who work in several places each weck reported to a central headquarters, they were requested to name the place in which they began work each day. If work was not begun at a central place each day, the person was asked to report the city and county in which he had worked the greatest number of hours.

Means of transportation to work refers to the principal mode of travel or type of conveyance used in traveling to and from work by civilians at work and Armed Forces personnel not on leave, sick, etc. For persons who used more than one means in daily travel, the enumerator was instructed that "principal means" referred to the means of transportation covering the greatest distance. For persons who used different means on different days, the enumerator was instructed that the proper response was the means of transportation used most frequently.

HOUSING CHARACTERISTICS

Living quarters.-Living quarters were enumerated as housing units or group quarters. Occupied living quarters were classified as housing units or group quarters on the basis of information supplied by household members on the Advance Census Report and questions asked by the enumerator where necessary. Identification of vacant housing units was based partly on observation by the enumerator and partly on information obtained from owners, landlords, or neighbors.

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 of the unit.

Occupied quarters which do not qualify as housing units are classified as group quarters. They are located most frequently in institutions, hospitals, nurses' homes, rooming and boarding houses, military and other types of barracks, college dormitories, fraternity and sorority houses, convents, and monasteries. Group quarters are also located in a house or apartment in which the living quarters are shared by the person in charge and five or more persons unrelated to him. Group quarters are not included in the housing inventory, although the count of persons living in them is included in the population figures.

The inventory of housing units includes both vacant and occupied units. Newly constructed vacant units were included in the inventory if construction had reached the point that all the exterior windows and doors were installed and the final usable floors were in place. Dilapidated vacant units were included provided they were still usable as living quarters; they were excluded if they were being demolished or if there was positive evidence that they were to be demolished.

Trailers, tents, boats, and railroad cars were included in the housing inventory if they were occupied as housing units. They were excluded if they were vacant, used only for extra sleeping space or vacations, or used only for business.

In 1950, the unit of enumeration was the dwelling unit. Although the definition of the housing unit in 1960 is essentially similar to that of the dwelling unit in 1950, the housing unit definition was designed to encompass all private living quarters, whereas the dwelling unit definition did not completely cover all private living accommodations. The main difference between housing units and dwelling units is as follows: In 1960, separate living quarters consisting of one room with direct access but without separate cooking equipment qualify as a housing unit whether in an apartment house, rooming house, or house converted to apartment use; in hotels, a single room qualifies as a housing unit if occupied by a person whose usual residence is the hotel or a person who has no usual residence elsewhere. In 1950, a one-room unit without cooking equipment qualified as a dwelling unit only when located in a regular apartment house or when the room constituted the only living quarters in the structure.

The evidence thus far suggests that using the housing unit concept in 1960 instead of the dwelling unit concept as in 1950 had relatively little effect on the counts for large areas and for the Nation. Any effect which the change in concept may have on comparability can be expected to be greatest in statistics for certain census tracts and blocks. Living quarters classified as housing units in 1960 but which would not have been classified as dwelling units in 1950 tend to be clustered in tracts where many persons live separately in single rooms in hotels, rooming houses, and other light housekeeping quarters. In such areas, the 1960 housing unit count for an individual tract may be higher than the 1950 dwelling unit count even though no units were added by new construction or conversion.

Occupied housing unit.-A housing unit is "occupied" if it was the usual place of residence for the person or group of persons living in it at the time of enumeration. Included are units occupied by persons who were only temporarily absent (for example, on vacation) and units occupied by persons with no usual place of residence elsewhere.

Vacant housing unit.--A housing unit is "vacant" if no persons were living in it at the time of enumeration. However, if its occupants were only temporarily absent, the unit was considered occupied. Units temporarily occupied by persons having a usual place of residence elsewhere were considered vacant (classified as "non