The 2003, 2004, and 2005 ACS 1-year PUMS files have been revised by applying a modified age perturbation edit to these files. This is the same revision that was made to the 2006 ACS 1-year PUMS files that is described in ACS Errata Note #50.

Age perturbation is one of several disclosure avoidance techniques used in the creation of the ACS PUMS files. It disguises original data by randomly adjusting the reported ages for a subset of individuals. As discussed in Errata Note #47, this technique in some previous years of ACS PUMS processing resulted in inconsistent sex ratios for selected age groups, especially ages 65 and over. The modified age perturbation edit was applied to people aged 65 and over to reduce inconsistencies among this group. The revised file estimates for people 65 years and older align closer to the ACS full sample by single year of age for sex ratios, social security participation, labor force participation, person income and home ownership. The sex ratio inconsistencies for persons aged 65 and over will not be seen in the 2006-2008 ACS 3-year PUMS files since the 2006 ACS 1-year PUMS files were revised before the 2006-2008 3-year PUMS files were created.

Several other minor corrections were made to the 2005-2007 3-year PUMS files. The factor to adjust housing dollar amounts for inflation (ADJHSG) has been moved from the person-level files to the housing unit-level files, which will make it consistent with the documentation. The factor to adjust income and earnings dollar amounts for inflation (ADJINC) has been corrected for the 2007 cases on the 2005-2007 files. The occupation code (SOCP) for the 2005 cases on the person-level file have been updated to be consistent with the new occupation codes used for the 2006 and 2007 cases.

The original PUMS files have been removed and replaced with the revised PUMS files for the affected releases. To request the original PUMS files, please send an e-mail to acso.users.support@census.gov.