Demographic data on this site is provided by Applied Geographic Solutions,
Inc. (AGS). AGS uses a wide range of data sources in constructing its estimates
and projections, including:
Census tabulations from 1970, 1980, 1990 and most recently, the release
of the 2000 Census
Census Bureau estimates and projections of population characteristics at
various levels of geographic detail, including the latest estimates of population
at the city level
Bureau of Labor Statistics estimates and projections of employment by industry
and occupation at the county level
Medicare eligible population counts at the ZIP code level, including population
by sex and 5- year age cohorts, provided by the Health Care Financing Administration
of Social Security. These counts provide a very accurate local count of the
population aged 65 and higher.
Internal Revenue Service statistics on tax filers and year-to-year migration
The Census Bureau Current Population Survey, which provides detailed demographic
breakdowns and enables a thorough longitudinal analysis of demographic trends
Experian's INSOURCE database, a household level credit and demographic database
that covers the vast majority of households.
INSOURCE is a vast database at the household and individual level that Experian
provides to AGS for use in its demographic estimates. The INSOURCE database
was aggregated to the ZIP+4 and Block Group levels of geography for analysis
and standardized to Census Bureau county level current estimates. A large
number of demographic attributes from INSOURCE were utilized in building the
2002B estimates, including:
• Population
• Population by Age
• Households
• Household Size
• Household Type (presence of children)
• Marital Status
• Income
• Hispanic origin
• Population of Asian origin
• Dwelling Tenure (own/rent)
• Length of Residence
Other methodology
A number of other variables are also projected within the series. In large
part, these are derived by using available current estimates and projections
at the lowest possible level of geography as the base for the estimation procedures.
The CPS is used extensively to track changes using available cross-reference
information related to age, race, sex, and income. Where possible, these CPS
statistics are supplemented by INSOURCE estimates.
For example, current marital status estimates are available at the state level
from the Census Bureau as “control targets”. The CPS surveys (both
historical and current) are used to track the changes in marital status dependent
upon other symptomatic variables such as age, sex, race, and income levels.
These “micro-models” are then applied to the block group level changes
between the census and the current period. This results in block group level
data that is consistent with higher order levels but also reflects changes in
marital status owing to shifting local demography.
On the other hand, vacant housing is tracked using state and regional indicators,
then adjusted for seasonally vacant dwellings that are a significant component
of the marketing landscape in many areas of the country.
