Digital Spatial Data

US Census

PUMS - Public Use Microdata Samples

PUMS, or Public Use Microdata Samples, are datasets consist of individual records of population and households without name of addresses, and that are released for large geographic areas of 100,000 or more population. PUMS data are taken from the sample questionnaires, so they contain the full set of data obtained by the census. The advantage of PUMS, compared to the summary files, is that users can create own variables and summarize them as they like. One of the drawbacks of PUMS, on the other hand, is that geography is limited to the large areas, thus generally not suitable for small geographic area analysis. Another drawback of PUMS is that PUMS requires full undestanding on the data structure and knowledge on computerized data format since PUMS is only available on computer tape or CD-ROM.

PUMS use example 1: inter-racial marriage study -- how many interracial married couples are in each state? Are the distribution patterns the same over the nation? Are there any geographic differences? Are there more black-male and white-female couples than white-male and black-female couples? Map left showing ratios of  non-hispanic white and minorities married couples to all couples (geography - PUMA).

PUMS use example 2: Milwaukee local paper cited a study done by researchers who worked for a foundation associated with conservative positions on educational issues. It reported that "public school teachers who live in Milwaukee are more likely to send their children to private schools than city residents in general, according to an analysis of 2000 census data. (Milwaukee Journal Sentinel, Sept. 16, 2004)" Such information is not available from summary files which are commonly used, but is available from 2000 PUMS. PUMS allows researchers to create variables of own interest.

PUMS Data Sources 

IPUMS - Integrated Public Use Microdata Series (by Minnesota Population Center, University of Minnesota) (web)
http://www.ipums.org/
IPUMS.ORG provides historical PUMS data files by allowing users to select and extract data that they need. They also provides detailed data dictionaries. Except for cartographic boundary files, almost everything a researcher needs to conduct PUMS data analysis is available from this site. 

Inter-University Consortium For Political and Social Research (ICPSR) (web)
http://www.icpsr.org/
Various years of PUMS files are also available from ICPSR.

PUMS Electronic Sources at the UW-Milwaukee Libraries (CD) (UWM Libraries)
A variety of electronic resources, which were obtained from the Census Bureau, are available for the in-house use at the UWM Libraries' reference information counter located on the 1st floor. ID card is required to use the CDs. Use PantherCat to identify call number of the data files you need.

PUMS Boundary Data Sources 

2000 - US Census: Cartographic Boundary Files (web)
http://www.census.gov/geo/www/cob/index.html
The boundary files relevant to 2000 PUMS are PUMAs (Public Use Microdata Areas - 5% sample) and Super-PUMAs (Super Public Use Microdata Areas - 1% sample). 2000 PUMA files are available from the US Census Bureau. Available formats are ArcInfo export (e00), shapefiles, and ArcInfo Ungenerate formats.

1990 - CIESIN Archive of Census Related Products (ACRP) (web)
http://sedac.ciesin.org/plue/cenguide.html#pumadata
The 1990 PUMA boundaries files consisting of a 5% sample and 1% sample areas are available from CIESIN's website. Available formats are Atlas agf, bna, and shapefiles.

PUMS Geography

PUMS geography varies depending on years. Visit IPUMS.ORG (Minnesota Population Center, University of Minnesota)'s "geographic tools" page to see historical PUMS boundary maps.

Return to top of page

Comments for the AGSL? Send them to agsl@uwm.edu.