This report is based on a transcription and tabulation of data from the 1950 Census of Population and Housing. The statistics relate to dwelling units considered substandard by the Public Housing Administration, in accordence with the contract for these statistics between the Bureau of the Census and the housing Authority of the City of Laurel.

A dwelling unit is considered substandard by the Public Housing Administration if it is either dilapidated or does not have the following plumbing facilities: flush toilet and bath inside the structure for the unit's exclusive use, and hot running water. The Public Housing Administration considers the absence of hot running water to be evidence generally of poor

ality of the dwelling unit, but there may be some localities in which the absence of hot running water is not deemed to be a sufficient indication by itself of poor quality. In such localities, a revised count of substandard units may be obtained from table 1 by subtracting from the total the units which lack hot water only. If it is desired to eliminate the units lacking bot water only from the total count of substandard units, the distributions shown in the tables will not be materially affected.

The criteria used to define substandard units in these tabulations are not identical with the housing characteristics included in the published reports from the 1940 Census. Therefore, any comparison of data in this report with the 1940 results must be made with extreme care. A direct comparison cannot be made with the 1940 results because information on hot running water wes not collected at that time. Further, the 1940 data on condition were collected showing dwelling units "needing major repairs," whereas

The data are presented in the series of attached tables. In table 1 the structural and occupancy characteristics are shown for all substandard dwelling units. Table 2 shows the rent paid for renter-occupied substandard units; table 3 shows the condition and plumbing facilities of these same units. Table 4 shows the characteristics of all families (both primary and secondary) living in the substandard units. Table 4a classifies the primary families by fanily income. Table 5 classifies primary families with no subfamily or secondary family present, by rent as a percent of family income.

Primary family. --A primary family consists of two or more persons including the head of the household and all (one or more) persons in the household who are related to the head by blood, marriage, or adoption. It may include a subfamily consisting of a married couple with or without children, or one parent with one or more children under 18 years of age, living in the household and related to but not including the head of the household or his wife. The subfamily is considered a part of the primary family for ail tabulation purposes.

3. The amount of other money income received in 1949, such as interest, dividends, veterans' allowances, pensions, or rents.

Gross rent.--Monthly gross rent is contract rent plus the reported average monthly cost of water, electricity, gas, and other fuel paid for by the renter. If furniture is included in the contract rent, the reported estimated rent of the dwelling unit without furniture is used for the computation instead of the contract

rent.

SOURCE AND RELIABILITY OF THE DATA

The data in tables 1 through 4 are based on complete counts, including all dwelling units and families with the specified characteristics. The distributions involving income in tables 4a and 5, however, were prepared from data collected on a sample basis. As part of the 1950 Census, family income data were obtained from about one-fifth of all families. For these tabulations, additional interviews were made to increase the income sample above the 20 percent level. This was accomplished by a subsequent field enumeration of a sample of families who were not in the original sample but were living in substandard dwelling units.

Although the figures shown in tables 1 through 4 are based on the same data as the forthcoming 1950 Census tabulations of these items, they may differ from those to be published as part of the Census. The present tables were obtained by tabulating directly the data as transcribed in the field offices of the Census Bureau and the figures therefore do not include all of the refinements that result from a careful examination of the schedules.

In addition, the data are subject to other biases due to errors of response or nonreporting which cannot be corrected in editing. Factors affecting the accuracy of enumeration include the respondent's knowledge of the facts and the ability of the enumerator to obtain accurate information on such items as income, rent, dilapidation and plumbing facilities. The regular 1950 tabulations are also subject to these biases.

Reliability of Estimates in Tables 48 and 5

Because of sampling variability, percentage distributions shown in table 4a and all figures in table 5 may differ from those that would have been obtained from a complete count. (The ab

The sampling variability of a specified percentage of total primary families with designated characteristics will vary according to the proportion of white families and nonwhite families making up this percentage. For example, consider the sampling variability of a figure of 10 percent based on total primary families. The maximum sampling error to be expected of such a figure would occur when the entire 10 percent includes only nonwhite primary families and the chances are about 19 out of 20 that this sampling error would not exceed 1.9 percent. The minimum sampling error would occur when the entire 10 percent includes only white primary families and the chances are 19 out of 20 that this

sampling error would not exceed 1.3 percent. For other specific characteristics composed of 10 percent of total primary families the sampling variability may assume any value between these two figures.

Reliability of absolute figures in table 5.-The approximate sampling variability of the absolute figures in table 5 is shown below. The chances are 19 out of 20 that differences between the numbers shown in table 5 and the numbers that would have been obtained from a complete census would be less than the sampling errors which follow.