Data Dictionary: Census 2000
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Survey: Census 2000
Data Source: U.S. Census Bureau
Universe: Occupied housing units
Variable Details
H49. Plumbing Facilities By Occupants Per Room By Year Structure Built
Universe: Occupied housing units
H049023 Lacking complete plumbing facilities
Aggregation method:
Addition
Relevant Documentation:
Excerpt from: Social Explorer, U.S. Census Bureau; 2000 Census of Population and Housing, Summary File 3: Technical Documentation, 2002.
 
Plumbing Facilities
The data on plumbing facilities were obtained from answers to long-form questionnaire Item 39, which was asked on a sample basis at both occupied and vacant housing units. Complete plumbing facilities include: (1) hot and cold piped water, (2) a flush toilet, and (3) a bathtub or shower. All three facilities must be located inside the house, apartment, or mobile home, but not necessarily in the same room. Housing units are classified as lacking complete plumbing facilities when any of the three facilities is not present.

Comparability
The 1990 census and Census 2000 data on complete plumbing facilities are not strictly comparable with the 1980 data. Before 1990, complete plumbing facilities were defined as hot and cold piped water, a bathtub or shower, and a flush toilet in the housing unit for the exclusive use of the residents of that unit. In 1990, the Census Bureau dropped the requirement of exclusive use from the definition of complete plumbing facilities. Of the 2.3 million year-round housing units classified in 1980 as lacking complete plumbing for exclusive use, approximately 25 percent of these units had complete plumbing but the facilities also were used by members of another household. From 1940 to 1970, separate and more detailed questions were asked on piped water, bathing, and toilet facilities. Prior to 1990, questions on plumbing facilities were asked on a 100-percent basis. In 1990 and Census 2000, they were asked on a sample basis.

Excerpt from: Social Explorer, U.S. Census Bureau; 2000 Census of Population and Housing, Summary File 3: Technical Documentation, 2002.
 
Occupants per Room
Occupants per room is obtained by dividing the number of people in each occupied housing unit by the number of rooms in the unit. The figures show the number of occupied housing units having the specified ratio of people per room. Although the Census Bureau has no official definition of crowded units, many users consider units with more than one occupant per room to be crowded. Occupants per room is rounded to the nearest hundredth. This item was derived from questions asked on a sample basis.

Mean occupants per room
This is computed by dividing occupants in housing units by the aggregate number of rooms. This is intended to provide a measure of utilization or crowding. A higher mean may indicate a greater degree of utilization or crowding; a low mean may indicate underutilization. Mean occupants per room is rounded to the nearest hundredth. (For more information on means, see "Derived Measures".)

Excerpt from: Social Explorer, U.S. Census Bureau; 2000 Census of Population and Housing, Summary File 3: Technical Documentation, 2002.
 
Year Structure Built
The data on year structure built were obtained from answers to long-form questionnaire Item 35, which was asked on a sample basis at both occupied and vacant housing units. Year structure built refers to when the building was first constructed, not when it was remodeled, added to, or converted. For housing units under construction that met the housing unit definition-that is, all exterior windows, doors, and final usable floors were in place-the category "1999 or 2000" was used for tabulations. For mobile homes, houseboats, RVs, etc., the manufacturers model year was assumed to be the year built. The data relate to the number of units built during the specified periods that were still in existence at the time of enumeration.

Median year structure built
Median year structure built divides the distribution into two equal parts: one-half of the cases falling below the median year structure built and one-half above the median. Median year structure built is computed on the basis of a standard distribution (see the "Standard Distributions" section under "Derived Measures"). Median year structure built is rounded to the nearest whole number. Median age of housing can be obtained by subtracting median year structure built from 2000. For example, if the median year structure built is 1967, the median age of housing in that area is 33 years (2000 minus 1967). (For more information on medians, see "Derived Measures".)

Limitation of the data
Data on year structure built are more susceptible to errors of response and nonreporting than data on many other items because respondents must rely on their memory or on estimates by people who have lived in the neighborhood a long time.

Comparability
Data on year structure built were collected for the first time in the 1940 census. Since then, the response categories have been modified to accommodate the 10-year period between each census. In the 1980 census, the number of units built before 1940 appeared to be underreported. In an effort to alleviate this problem, a "Don't know" category was added in 1990. Responses of "Don't know" were treated like blanks and the item was allocated from similar units by tenure and structure type. However, this led to an extremely high allocation rate for the item (28 percent). A 1996 test proved inconclusive in determining whether a "Don't know" category led to a more accurate count of older units, but the test showed the allocation rate for this item was greatly reduced by the elimination of the "Don't know" category. As a result, "Don't know" was deleted for Census 2000.