During the first half of the decade, the annual increase in the number of households averaged about 650,000, according to the results of sample surveys made by the Bureau of the Census, Department of Commerce. There were an estimated 47.8 million households in April 1955 as compared with 43.6 million in March five years earlier. This increase was not shared uniformly. Urban and rural-nonfarm households in the United States increased by about a million a year during the period 1950 to 1955, whereas ruralfarm households showed a decline of close to 150,000 a year. In March 1950, there were 37.3 million urban and rural-nonfarm households and 6.3 million ruralfarm households. According to the most recent survey, however, there were 42.2 million nonfarm households and 5.5 million farm households in April 1955.

The count of households is equivalent to the number of occupied dwelling units. The increase in nonfarm households for a given period, however, may differ considerably from the number of nonfarm housing starts reported by the Bureau of Labor Statistics because two different types of measures are involved. Demolitions, conversions, changes in the supply of vacant housing, shifts between farm and nonfarm usage, and differences in definition affect the relationship between the increase in nonfarm households and the number of nonferm housing starts.

Table 2 shows the estimated number of households by type and urban-rural residence in 1955. Of all households, 67 percent were living in urban areas, 21 percent in rural-nonfarm areas, and 12 percent on rural farms. Of all rural-farm households, 84 percent were husband-wife households; the corresponding proportion for urban areas was only 73 percent. On the other hand, 20 percent of the urban households had a female head, as compared with only 8 percent of the rural-farm households.

The rural-farm household figures in tables 1 and 3 for the years 1947 to 1953 represent revised figures obtained by computing the ratio of the original farm population estimates from the Current Population Survey to the revised farm population estimates published in Series Census-BAE, No. 16, and Census-AMS, No. 20, and applying this ratio to the rural-farm household figures based on surveys for 1947 to 1953. Because of the use of the expanded sample

Total...

Urban and rural nonfarm..... Rural farm....

1

1947 TO 1955

April 1955

April 1954

April 1953

April 1952

April

1951

March 1950

April 1949

April 1948

April 1947

42,243,000 5,545,000

Revised; see text.

Table 4 presents estimates of the number of households, families, and related types of units for each of the years from 1947 to 1955. Residence detail for family units other than households are not yet available for 1955 but will be presented in a forthcoming report.

Annual increases in the number of households, families, and other types of units which may be computed from tables 3 and 4 should be used with full realization that they may be in substantial error. Many of the apparent differences in annual growth may not be the same as the differences in annual growth that would be found by a complete enumeration. These changes are small relative to the total number of family units, and consequently estimates of such changes are sensitive to small errors in the estimates of the total number. The joint effect of sampling variability and any biases of response and coverage on the estimates of the total number of units for each year is, therefore, large in relation to the amount of the annual increase. Since data are not available to permit realistic estimates of the size and effect of these biases, and since some of the judgments as to size of these biases suggest that they are larger than the effects of sampling variability, estimates of the sampling variability are not included in this report. Because of the variability in the measures of annual changes, tables 1 and 4 feature changes over periods of several years.

Definitions.--The definition of urban and rural areas used in the present report is the same as that used in the 1950 Census. According to the new definition adopted for use in the 1950 Census, the urban population comprises all persons living in (a) places of 2,500 inhabitants or more incorporated as cities,

boroughs, and villages, (b) incorporated towns of 2,500 inhabitants or more except in New England, New York, and Wisconsin, where "towns" are simply minor civil divisions of counties, (c) the densely settled urban fringe, including both incorporated and unincorporated areas, around cities of 50,000 or more, and (d) unincorporated places of 2,500 inhabitants or more outside any urban fringe. The remaining population is classified as rural. The territory classified as urban is the same as that in the 1950 Census, since it is not feasible to take into account population growth in certain communities or annexations of territory since the census date.

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.

A household includes all of the persons who occupy a house, an apartment or other group of rooms, or a room, that constitutes a dwelling unit. Quasi households, such as groups of persons living in institutions, hotels, and large rooming houses, are

not counted as households.

The term "family," as used here, refers to a group of two persons or more related by blood, marriage, or adoption and residing together; all such persons are considered as members of one family. A primary family includes the head of a household and a secondary family does not. Secondary families are generally roomers or resident employees in ordinary homes or rooming houses.

A subfamily is a married couple with or without children, or one parent with one or more children

Source of data for 1947 to 1955.--The estimates for 1947 to 1955 presented in this report are based on data obtained in connection with the monthly population sample survey of the Bureau of the Census. The statistics for 1954 and 1955 are based on a new sample design instituted in January 1954. This sample is spread over 230 sample areas comprising 453 counties and independent cities. A total of 24,000 to 26,000 dwelling units and other living quarters are designated for the sample at any time, and completed interviews are obtained each month from about 20,000 to 22,000 households. of the remainder, about 500 to 1,000 are households for which information should be obtained but is not (1.e., households temporarily absent, households living in areas with impassable roads, etc.), and the rest are vacant dwellings or those otherwise not to be enumerated for the survey. The data for 1947 to 1953, for which similar information was obtained, are based on a different sample, which consisted of about the same number of units but which covered only 68 sample areas.