Reducing the Infeasibility and Oversuppression for M-LP Cell Suppression

• Activity Number: 245
• Type: Contributed
• Date/Time: Monday, August 10, 2015 : 2:00 PM to 3:50 PM
• Sponsor: Government Statistics Section
• Author(s): Bei Wang*
• Companies: U.S. Census Bureau
• Keywords: cell suppression ; LP ; m-LP ; Infeasible ; disclosure avoidance ; Economic Census

Abstract

The 2012 Economic Census uses cell suppression to protect sensitive information. We general use 1-LP sequential approach for small table and m-LP partial simultaneous approach for large table. This research is about limiting oversuppression and infeasibility caused by grouping particular cells together in m-LP. - We have some examples illustrating why and how m-lP causes infeasibility and oversuppression. - We establish a baseline to evaluate oversuppression. The baseline uses 1-LP, but given a particular n, there n! outcomes needed to run 1-LP multiple times to get an average and variance. We use a 3-d table from the 2012 Economic Census. - We develop some algorithms to reduce infeasibilities. The general idea is to set m cells wide apart in terms of relationships such that each targeted cell finds its own protection without interacting each other. We identify a class of cells which should be done first and fit this into our algorithm for forming m-groups. This research should benefit the 2017 Economic Census.