The American Community Survey (ACS) Protected Identification Key (PIK) Crosswalks are used to link ACS microdata files to other microdata files with a Protected Identification Key (PIK) variable.
The ACS is part of the Decennial Census Program. This survey is sent to a random sample of households in the United States and Puerto Rico on a rotating basis. The ACS collects information from U.S. households similar to what was collected on the decennial census "long form."
