units inside SMSA's remained at the 1965 level whereas units outside SMSA's continued to increase.

Among the regions, the Northeast ranked lowest in the proportion of vacancies "held off market." For each region except the West, vacant units "held off market" show an upward trend between 1956 and 1965. In 1966 and 1967, the trend in the South seems to have continued upward; in the Northeast and North Central Regions, the levels reached in 1965 have continued. In the West, the level of vacant units "held off market" fluctuated slightly between 1956 and 1964 but has been stable since 1965.

Year-round vacancies that were found to be dilapidated (but still considered living quarters) amounted to 1.0 percent of all housing units in the United States in 1956. By 1965, vacant dilapidated units declined to 0.7 percent and remained at this level through 1967. The decline in dilapidated units occurred entirely outside metropolitan areas.

During the 1956 to 1965 period, there is some evidence that the Northeast had the smallest proportion of vacant dilapidated units while the South had the highest. In 1966 and 1967, all regions except the Northeast seem to have had relatively fewer dilapidated vacancies than in previous years.

Between 1956 and 1967, the trend in vacant seasonal units continued at the same level for the United States as a whole. There was also no change in the level of vacant seasonal units inside SMSA's. Outside SMSA's, where most of the seasonal vacancies were located, the percentage rose sharply between 1956 and 1965 but moved downward from 1965 to 1967.

Among the geographic regions, the Northeast had the highest proportion of seasonal vacancies

and showed the most stability in the level of such units. The North Central Region and the South had relatively fewer seasonal vacancies in 1956 but showed noticeable increases by 1965. In 1966 and 1967, the Northeast and the North Central regions continued at the 1965 level in the percentage of vacant seasonal units; the South dropped to the 1956 level. The West, where the percentage of seasonal vacancies was the same as that for the North Central and South Regions in 1956, ranked lowest from 1960 through 1967.

OCCUPANCY AND VACANCY RATES

Table J illustrates that the percentage relationship between total rental units and all housing units has remained at approximately the same level from 1956 to 1967. Total rental units amounted to 35.2 percent of all housing units in 1967 which is not significantly different from the 38.6 percent in 1956. The total number of rental units, however, increased steadily during the 12-year period. Between 1956 and 1965, the proportionate increase in the number of vacant rental units was far greater than that in the number of occupied rental units. This resulted in a rise in the rental vacancy rate. In 1966 and 1967, the pattern was reversed. The number of renteroccupied units remained about the same as in 1965, while the number of vacant rental units decreased. This resulted in a drop in the rental vacancy rate. A similar situation exists among homeowner units. Although the total number of homeowner units increased substantially, a relatively larger increase occurred among vacant forsale units in the period 1956 to 1965, thereby increasing the vacancy rate in homeowner units. In 1966 and 1967, the increase in the number of owner-occupied units was relatively small, which probably reflects the decline in housing starts, while the decrease in the number of vacant for

sale units was relatively large. This resulted in a drop in the vacancy rate in homeowner units. Tenure of occupied units.-- In 1956, approximately 60.0 percent of all households in the United States owned their own homes. By 1967, the percentage for homeowners had moved slowly up to 63.6 percent (table K).

Owner-occupancy rates were sustained at a much higher level outside SMSA's than rates inside SMSA's. Outside metropolitan areas, the owneroccupancy rate moved from 64.6 percent in 1956 to 70.0 percent in 1967; within metropolitan areas, the rate was 57.0 percent in 1956 and 60.2 percent in 1967.

In the Northeast, North Central, and South Regions, owner-occupancy rates followed the national pattern, moving slowly upward over the 12-year period. In the West, on the other hand, owneroccupancy rates showed an upward movement from

1956 to 1960, a gradual decline from 1961 to 1965, and a slight upward movement from 1965 to 1967.

Table K.--Annual Average Owner-Occupancy Rate: 1956, 1960, and 1965 to 1967

Area

United States.

Inside SMSA's... Outside SMSA's..

Northeast....

North Central.
South.
West

Except for the instances noted below, the concepts and definitions used in the quarterly surveys are identical with those used in the 1960 Census.

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, the smaller of which must have at least 15,000. 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. New England, SMSA's consist of towns and cities, rather than counties. A more detailed discussion of the criteria used to define SMSA's is given in 1960 Census of Housing, Volume I, States and Small Areas.

The statistics presented for inside SMSA's and outside SMSA's beginning the second quarter 1962 relate to the areas (212) designated SMSA's at the time of the April 1960 Census. Prior to the second quarter 1962, the statistics related to the areas (168) designated SMA's at the time of the 1950 Census. For a list of the 212 SMSA's and their constituent parts, refer to the individual chapters (or Series HC(1) reports) in the 1960 Census of Housing, Volume I, States and Small Areas; or to the 1960 Census of Population, Volume I, Number of Inhabitants. For a list of the 168 areas and their constituent parts, refer to the individual chapters (or bulletins) in the 1950 Census of Housing, Volume I, General Character

istics; or to the 1950 Census of Population, Volume I, Number of Inhabitants, or Volume II, Characteristics of the Population,Part I, United States Summary.

Housing unit.--Beginning with the second quarter 1960, the 1960 Census housing unit concept was used to enumerate separate living quarters. Prior to that time, separate living quarters were enumerated according to the 1950 dwelling unit definition. The major difference between the two is not in content but in sharpening of the criteria by which separate units are identified. It is expected that the housing unit concept will yield better coverage of both occupied and vacant living quarters than the dwelling unit concept. Although no statistical measure of the effect of the change is available at this time, it is believed to be too small to affect the vacancy rates.

A group of rooms, or a single room, is regarded as a housing unit when it is occupied as separate living quarters, that is, when the occupants do not live and eat with any other persons in the structure, and when 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.

Vacant living quarters which are intended for occupancy as separate living quarters and meet the physical criteria defined above are separate housing units. Since it is customary in some localities for occupants to furnish their own cooking equipment, vacant units without a kitchen or cooking equipment are considered to have such equipment if the last occupants had cooking equipment.

Living quarters of the following types are excluded from the housing unit inventory: Dormitories, bunkhouses, and barracks; quarters in predominantly transient hotels, motels, and the like, except those occupied by persons who consider the hotel their usual place of residence; quarters in institutions, general hospitals, and military installations except those occupied by staff members or resident employees who have separate living arrangements.

Quarters for roomers or boarders having shared living arrangements are excluded from the housing inventory if there are five or more such rooms; they are combined as one housing unit if there are four or fewer such rooms.

Trailers, tents, and boats are excluded if vacant, used for business, or used for extra sleeping space or vacations.

Dwelling unit, 1950.--The 1950 dwelling unit was defined as follows: A group of rooms occupied as separate living quarters was a dwelling unit if it had separate cooking equipment or if it constituted the only living quarters in the structure. Each apartment in a regular apartment house was a dwelling unit even though it may not have had separate cooking equipment. Apartments in residential hotels were dwelling units if they had separate cooking equipment or consisted of

two or more rooms.

Vacant quarters which were intended for Occupancy as separate living quarters and met the physical criteria defined above were separate dwelling units. Vacant units were considered as having cooking equipment if they were equipped with such equipment or if the last occupants had cooking equipment.

In general, living quarters of the types excluded from the housing unit inventory were excluded from the dwelling unit inventory.

Occupied housing units.-- A housing unit is occupied if a person or group of persons was living in it at the time of enumeration or if the occupants were only temporarily absent, as for example, on vacation. The persons living in the unit must consider it their usual place of residence or have no usual place of residence elsewhere. The count of occupied housing units is the same as the count of households.

Units occupied by persons with usual residence elsewhere.-- A housing unit which is occupied temporarily by persons who usually live elsewhere is enumerated as a vacant unit provided the usual place of residence is held for the household and is not offered for rent or for sale. For example, a beach cottage occupied at the time of enumeration by a family which has a usual place of residence in the city is included

in the count of vacant units. Their house in the city would be reported "occupied" and would be included in the count of occupied units since the occupants are only temporarily absent.

Units occupied by persons with usual residence elsewhere are included with seasonal units or with year-round vacant units as dilapidated, or not dilapidated but held off the market, as the case may be.

Vacant housing units. --A housing unit (furnished or unfurnished) is vacant if no persons were living in it at the time of enumeration, except when its occupants were only temporarily absent. Dilapidated vacant units were included if they were intended for occupancy as living quarters; however, if the vacant unit was unfit for use and beyond repair so that it was no longer considered living quarters, it was excluded from the inventory. Vacant units to be demolished were excluded if unfit or if there was positive evidence, such as a sign or mark on the house or in the block, that the unit was to be torn down. New units not yet occupied were enumerated as vacant housing units if construction had proceded to the point that all the exterior windows and doors were installed and final usable floors were in place; otherwise, potential units under construction were not included. Unoccupied units held off the market for various reasons and units recently rented or sold but not yet occupied are considered vacant.

Vacant sleeping rooms in lodginghouses, transient accommodations, barracks, and other quarters not defined as housing units are not included in the statistics in this report. (See section on "Housing unit.")

Year-round vacant units.--Year-round units are those intended for occupancy at any time of the year, even though they may not be in use the year round. In resort areas, a housing unit which is usually occupied on a year-round basis was considered a year-round unit. On the other hand, a housing unit located in the closely built-up area of a nonresort city was considered a "year round" unit even though it may be occupied only part of the year. As indicated above, year-round units temporarily occupied by persons with usual residence elsewhere are included with year-round vacant units.

Seasonal vacant units.--Seasonal housing units are those intended for occupancy during only a season of the year and are found primarily in resort areas. In farm areas, housing units used for only a portion of the year to house migratory workers employed during the crop season are classified as seasonal.

Seasonal units comprise unoccupied seasonal units and seasonal units temporarily occupied by

persons with usual residence elsewhere. Units in resort areas occupied by persons who considered the unit their usual place of residence or had no other place of residence are classified as occupied. (See also section on "Occupied housing units.")

Available vacant units.--The categories "available for rent" and "available for sale only" provide a measure of vacant housing units which are on the market for year-round occupancy, are in either sound or deteriorating condition, and are being offered for rent or for sale. These categories are comparable with the 1950 categories "Nonseasonal not dilapidated, for rent" and "Nonseasonal not dilapidated, for sale only."

To describe the rental and sale market, the measure of units available for rent is expressed as a percentage of the total rental inventory and the measure of units available for sale is expressed as a percentage of the total homeowner inventory. In the analysis of the total inventory and total vacant units, percentages are based on total housing units.

Vacant units available for rent.--This group consists of available vacant units offered for rent and those offered "for rent or sale."

Vacant units available for sale only. --This group is limited to units for sale only; it excludes units "for rent or sale." If a unit was located in a multiunit structure which was for sale as an entire structure and if the unit was not for rent, it was reported as "held off market." However, if the individual unit was intended to be occupied by the new owner it was reported as for sale.

Vacant units rented or sold. --This group consists of year-round vacant units in sound or deteriorating condition which have been rented or sold but the new renters or owners have not moved in as of the day of enumeration. In the 1950 statistics, such units are shown in combination with year-round not dilapidated vacant units held off the market.

Vacant units held off the market.--Included in this category are year-round units in sound or deteriorating condition which were vacant for reasons other than those mentioned above: For example, held for occupancy of a caretaker, janitor, and the like; held for settlement of estate; held for personal reasons of the owner; and temporarily occupied by persons who have a usual place of residence elsewhere. In the 1950 statistics, such units are shown in combination with year-round not dilapidated vacant units, rented or sold, as "nonseasonal not dilapidated, not for rent or sale" units.

Rental vacancy rate.--The percentage relationship of the vacant units available for rent to the total rental inventory is termed the rental vacancy rate. It is computed by dividing the number of vacant units available for rent by the total rental units. The total rental units consist of the renter-occupied units, vacant units rented but not yet occupied at the time of enumeration, and the vacant units available for rent. Vacant units that are dilapidated, seasonal, or held off the market are excluded.

Homeowner vacancy rate.--The percentage relationship between the vacant units available for sale and the total homeowner inventory is termed the homeowner vacancy rate. It is computed by dividing the number of vacant units available for sale by the total homeowner units. The total homeowner units consist of the owner-occupied units, vacant units sold and awaiting occupancy, and the vacant units available for sale. Vacant units that are dilapidated, seasonal, or held off the market are excluded.

Tenure.--A unit is owner-occupied if the owner or co-owner lives in the unit, even if it is mortgaged or not fully paid for. All other occupied units are classified as "renter occupied" whether or not cash rent is paid. Thus, units occupied in exchange for services rendered and units provided without payment of cash rent are "renter occupied."

Condition of housing unit. --The structural condition of a housing unit is considered one of the measures of the quality of housing. Beginning the first quarter 1961, the condition of vacant housing units was measured according to the concept used in the 1960 Census. Three categories were used: Sound, deteriorating, and dilapidated. In preceding quarters and in 1950, two categories were used: Not dilapidated, or dilapidated. The category "sound or deteriorating" is assumed to be equivalent to the category "not dilapidated."

Sound housing has no defects, or only slight defects which are normally corrected during the course of regular maintenance. Examples of slight defects include: Lack of paint; slight damage to porch or steps; small cracks in walls, plaster, or chimney; broken gutters or downspouts; slight wear on floors or door sills.

Deteriorating housing needs more repair than would be provided in the course of regular maintenance. It has one or more defects of an intermediate nature that must be corrected if the unit is to continue to provide safe and adequate shelter. Examples of such defects include: Shaky or unsafe porch or steps; holes, open cracks, or missing materials over a small area of the floors, walls, or roof; rotted window sills or

frames; deep wear on floors or doorsills; broken or loose stair treads or missing balusters. Such defects are signs of neglect which lead to serious structural damage if not corrected.

Dilapidated housing does not provide safe and adequate shelter. It has one or more critical defects, or has a combination of intermediate defects in sufficient number to require extensive repair or rebuilding, or is of inadequate original construction. Critical defects are those which indicate continued neglect and serious damage to the structure. Examples of critical defects include: Holes, open cracks, or missing materials over a large area of the floors, walls, roof, or other parts of the structure; sagging floors, walls, or roof; damage by storm or fire. Inadequate original construction includes structures built of makeshift materials and inadequately converted cellars, sheds, or garages not originally intended as living quarters.

The enumerator determined the condition of the housing unit on the basis of his own observation. He was instructed to appraise the condition of units uniformly, regardless of the neighborhood. The enumerator was provided with detailed written instructions and with pictures illustrating the concepts "sound," "deteriorating," and "dilapidated."

Although the enumerator was provided with detailed oral and written instructions and with visual aids, it was not possible to eliminate completely the element of judgment in the enumeration of this item. It is possible that some enumerators obtained too large or too small a count of dilapidated units. However, with the large number of enumerators involved, it is likely that such deviations tend to be offsetting.

A

Number of rooms.--All rooms which are to be used, or are suitable for use, as living quarters were counted in determining the number of rooms in the housing unit. Included are kitchens, bedrooms, dining rooms, living rooms, and permanently enclosed sunporches of substantial size; and finished basement or attic rooms, recreation rooms, suitable for use as living quarters. kitchenette or half-room which is partitioned off from floor to ceiling was counted as a separate room, but a combined kitchenette and dinette separated only by shelves or cabinets was counted as only one room. Not counted as rooms were bathrooms, strip or pullman kitchens, halls or foyers, alcoves, pantries, laundries, closets or storage space, and unfinished basement or attic rooms not suitable for living quarters.

The median number of rooms is the theoretical value which divides the housing units equally, one-half having more rooms and one-half having fewer rooms than the median. In the computation

of the median, a continuous distribution was assumed. For example, when the median was in the 3-room group, the lower and upper limits were assumed to be 2.5 and 3.5, respectively. Tenths were used in the computation of the median to permit comparisons.

Number of bedrooms. --Only rooms intended primarily to be slept in were counted as bedrooms. A bed-living room or a den intended primarily for purposes other than sleeping was not counted as a bedroom. A 1-room apartment, therefore. was reported as having no bedroom. Also, space which could be made into bedrooms (the upper floor of a 1 1/2-story house, for example) was not counted as a bedroom unless it was finished off and suitable for use as living quarters.

Number of housing units in structure.-- A structure either stands by itself or has vertical walls dividing it from all other structures. The count of housing units in a structure is the total number of units in the structure, including both occupied and vacant units. A structure may be detached, attached, or semidetached. A detached structure has open space on all four sides; and attached structure is one of a row of three or more adjoining structures, or is a structure attached to a nonresidential structure; while a semidetached structure is one of two adjoining residential structures, each with open space on the remaining three sides. In apartment developments, each building with open space on all sides is considered a separate structure.

The statistics reflect the number of vacant housing units classified by the number of housing units in the structure in which they are located, rather than the number of residential structures that contain vacant units.

In the quarterly surveys, data were obtained on the number of housing units in the structure, regardless of the type of structure (detached, attached, or semidetached) in which the unit was located.

Year structure built.--"Year built" refers to the date the original construction of the structure was completed, and not to any later remodeling, addition, or conversion. The figures on the number of units built during a given period relate to the number of units in existence at the time of enumeration. The figures reflect the number of units constructed during a given period plus the number created by conversions in structures originally built during that period, minus the number lost in structures built during the period. Losses occur through demolition, fire. flood, disaster; change to nonresidential use; or merger to fewer housing units.