This section is focused on Public Use Microdata Sample (PUMS) and associated Public Use Microdata Areas (PUMA).

 

Public Use Microdata Sample (PUMS)-- weighted sample response data for individuals and housing units

 

The PUMS data/files contain a sample of actual responses to the American Community Survey (ACS). The PUMS dataset includes variables for nearly every question on the survey, as well as many new variables that were derived after the fact from multiple survey responses (such as poverty status). Each record in the file represents a single person, or--in the household-level dataset--a single housing unit. In the person-level file, individuals are organized into households, making possible the study of people within the contexts of their families and other household members.

 

ACS 1 year files contain records for approximately one percent of the US population.

ACS 5 year files contain records for approximately five percent of the US population.

 

ACS 2010 and ACS 2011 PUMS files are supported by Crosstabs. Future files will be supported as released

 

Since all ACS responses are strictly confidential, many variables in the PUMS file have been modified in order to protect the confidentiality of survey respondents. High incomes are top-coded, uncommon birthplace or ancestry responses are grouped into broader categories, and the PUMS file provides a very limited set of geographic variables.

 

Public Use Microdata Areas (PUMA)-- geographic areas identified in the PUMS data records

 

The most detailed unit of geography contained in the PUMS files is the Public Use Microdata Area (PUMA). PUMAs are special non-overlapping areas that partition each state into geographic units originally defined as containing no fewer than 100,000 people each.

 

The 2006-2010 and 2007-2011 ACS PUMS files make use on PUMA boundaries defined as of Census 2000.

 

PUMA codes are 5-digit character codes with lead zeroes. The state FIPS code must be used with the state PUMA code to make the PUMA code unique within the U.S. For example, the PUMA code corresponding to Shawnee County, KS is 00800. PUMA 00800 is unique to Kansas PUMAs, but not to the national set of PUMAs. The combined state FIPS code 20 and PUMA code 00800 (2000800) is a unique national scope geocode.

 

CVXE Crosstabs and PUMS Files

Illustrative application using ACS 2006-10 5 year PUMS file