Main Article Content
Public Use Microdata Samples (PUMS) released by the U.S. Census Bureau and other data providers undergo various privacy protection transformations prior to public release of the individual records. We briefly review these methods but focus our attention on "top-coding" as implemented by the Census Bureau. In particular, we provide a brief analysis of the method used for top-coding of records within a hierarchy. We also show that top-coding artificially moves the correlation between two variables (at least one of which is top-coded) closer to zero by the transformation. We then discuss our attempts to recover the un-transformed data, or at least the original correlations, which all failed. In the final section we briefly discuss methods of disclosure avoidance in PUMS files which preserve joint probability distributions.
Copyright is retained by the authors. By submitting to this journal, the author(s) license the article under the Creative Commons License – Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), unless choosing a more lenient license (for instance, public domain). For situations not allowed under CC BY-NC-ND, short sections of text, not to exceed two paragraphs, may be quoted without explicit permission provided that full credit, including © notice, is given to the source.
Authors of articles published by the journal grant the journal the right to store the articles in its databases for an unlimited period of time and to distribute and reproduce the articles electronically.