4 Three factors usually affect the search for data from the Census Bureau: 1. topic (e.g., population) 2. geography (e.g., my state) 3. time period (e.g., most recent year).. Search for Data
5 Generally the larger the geographic area, the more topics and time periods you can find. U.S. level – Extensive data States and Counties - Substantial data Cities (i.e., incorporated places) – Somewhat less data Small areas (census tracts, block groups, and blocks) - once a decade after the Census Bureau tabulates the results of the Population and Housing Census. In 2010 - the American Community Survey will allow the Census Bureau to release data more frequently for areas as small as census tracts. Data Availability
6 Examples of Data by Small Geography Census 2000 Summary File 1 (100%) Census Tract Blocks - most tabulations Summary File 2 (100%) Census Tract Summary File 3 (Sample) Census Tract Block Group - most tabulations Summary File 4 (Sample) Census Tract
7 Examples of Data by Small Geography Economic Census - 2002 Zipcode level American Community Survey – 2006 Areas of 65,000+ population
9 Public Use Microdata Sample Microdata allow users to prepare their own customized tabulations of most population and housing subjects using specially prepared microdata files. These files are the actual responses to census questionnaires, but with names or addresses removed and the geography sufficiently broad to protect confidentiality.
10 What is a PUMA ? Public Use Microdata Area PUMA is a geographic entity for which extracts of the full range of population and housing data collected from a small sample of confidentiality-screened census records are provided. PUMAs are sub-state areas that can be composed of: A large single county or groups of counties Large places Groups of census tracts Combination of tract and county and Other variations
11 PUMA Delineation The Census Bureau offered State Data Centers (SDCs) the opportunity to delineate, or coordinate the delineation of, the super-PUMAs and the PUMAs. The SDCs (or their equivalents) in 48 states, the District of Columbia, and Puerto Rico participated in the delineation program. PUMA codes must be used in conjunction with the 2-digit FIPS state codes. PUMAs: Minimum population of 100,000 - cannot cross a state line. (5% long-form records sample) Super PUMAs: Aggregated PUMAs with a minimum population of 400,000 - cannot cross state lines. (1% long-form records sample)