Homeowners and Renters

Description of Data
Data sources
The Census data used in the report come from two sources - Summary Tape File 2a for 1990 and Summary Files 1 and 2 for 2000. The form in which housing data are tabulated by the census requires that we use households as the unit of analysis. Households are assigned to racial/ethnic categories based on the race/ethnicity of the household head. We use split tracts in order to distinguish accurately between city and suburban locations; split tracts located entirely in the city or suburbs are aggregated to whole tracts.

Group definition
Census 1990 provided separate tabulations for non-Hispanic whites, non-Hispanic blacks, Asians/Pacific Islanders (regardless of Hispanic origin), and Hispanics of any race. A small number of households (Hispanic Asians) are double-counted in both the Asian and the Hispanic categories.
Census 2000 tables were manipulated to approximate these same categories, although an exact match is not possible due to the introduction of mixed-race categories in 2000. In data from SF2 "non-Hispanic white" refers to non-Hispanics who report only white race. "Hispanic" draws from the tables for Hispanics, regardless of race. "Asian" draws from the tables for all household heads who report Asian race alone or in combination with another race, regardless of Hispanic origin. Non-Hispanic black refers to household heads who are black alone or in combination with another race and non-Hispanic.

Data suppression
 Census 2000 suppressed race-specific tables in Summary File 2 where the group count was 100 or less. To remedy data suppression we replace the missing tract information in Summary File 2 with similar information available from Summary File 1. For these tracts with few group members, SF1 provides exactly comparable tables for non-Hispanic whites and for Hispanics. For Asians and blacks, the use of SF1 tables introduces some error.

For Asians, SF1 refers to "Asians alone," resulting in an understatement of the number of Asian householders in the tract compared to the SF2 definition. Due to suppression, SF2 counts only 88.9% of Asians in metropolitan areas in the United States. Replacement from SF1 tables allows us to bring this up to 97.8%.

Use of SF1 to replace suppressed data for non-Hispanic blacks is more complex and also results in an understatement of the number of black householders. SF1 does not provide a table for non-Hispanic blacks; the number must be calculated from other tables. We begin with the number of blacks alone (blacks in combination with another race are lost). From this count we wish to remove Hispanic blacks. We approximate the number of Hispanic blacks by subtracting Hispanic whites (all "white alone" less "non-Hispanic white alone") from all Hispanics.

More precisely, the number is calculated by this formula: NHB = B-(H-(W-NHW)), where NHB is non-Hispanic blacks, B is all blacks (alone), H is all Hispanics, W is all whites (alone), and NHW is non-Hispanic whites (alone). Where the calculation yields a negative number, it is set to zero. This number is used only in those tracts where the actual count is suppressed in SF2.

Due to suppression, SF2 counts only 96.6% of non-Hispanic blacks in metropolitan areas in the United States. Replacement from SF1 tables allows us to bring this up to 98.1%.