Data Dictionary: Census 2000
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Survey: Census 2000
Data Source: U.S. Census Bureau and Social Explorer
Universe: Households
Variable Details
T96. Average Household Income In 1999 Dollars
Universe: Households
T096_001Average household income In 1999 Dollars
Percent base:
None - percentages not computed
Aggregation method:
Division of Sums: variables: Sum(T126_001) / Sum(T092_001)
Formula used to compute this variable:
if( SF3:P052001 == 0) Return_Value.IsNull = true; else Return_Value = SF3:P054001 / SF3:P052001;
Variables used in the formula:
Households: Aggregate household income In 1999 Dollars
Relevant Documentation:
Excerpt from: Social Explorer, U.S. Census Bureau; 2000 Census of Population and Housing, Summary File 3: Technical Documentation, 2002.
Mean income
Mean income is the amount obtained by dividing the aggregate income of a particular statistical universe by the number of units in that universe. Thus, mean household income is obtained by dividing total household income by the total number of households. (The aggregate used to calculate mean income is rounded. For more information, see "Aggregate income.")

For the various types of income, the means are based on households having those types of income. For households and families, the mean income is based on the distribution of the total number of households and families including those with no income. The mean income for individuals is based on individuals 15 years old and over with income. Mean income is rounded to the nearest whole dollar.

Care should be exercised in using and interpreting mean income values for small subgroups of the population. Because the mean is influenced strongly by extreme values in the distribution, it is especially susceptible to the effects of sampling variability, misreporting, and processing errors. The median, which is not affected by extreme values, is, therefore, a better measure than the mean when the population base is small. The mean, nevertheless, is shown in some data products for most small subgroups because, when weighted according to the number of cases, the means can be added to obtained summary measures for areas and groups other than those shown in census tabulations. (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.
A household includes all of the people who occupy a housing unit. (People not living in households are classified as living in group quarters.) A housing unit is a house, an apartment, a mobile home, a group of rooms, or a single room occupied (or if vacant, intended for occupancy) as separate living quarters. Separate living quarters are those in which the occupants live separately from any other people in the building and that have direct access from the outside of the building or through a common hall. The occupants may be a single family, one person living alone, two or more families living together, or any other group of related or unrelated people who share living quarters.

In 100-percent tabulations, the count of households or householders always equals the count of occupied housing units. In sample tabulations, the numbers may differ as a result of the weighting process.

Average household size
A measure obtained by dividing the number of people in households by the total number of households (or householders). In cases where household members are tabulated by race or Hispanic origin, household members are classified by the race or Hispanic origin of the householder rather than the race or Hispanic origin of each individual. Average household size is rounded to the nearest hundredth.