A public-use microdata file should be analytically valid. For a very small number of uses, the microdata should yield analytic results that are approximately the same as the original, confidential file that is not distributed. If the microdata file contains a moderate number of variables and is required to meet a single set of analytic needs of, say, university researchers, then many more records are likely to be re-identified via modern record linkage methods than via the re-identification methods typically used in the confidentiality literature. This paper compares several masking methods in terms of their ability to produce analytically valid, confidential microdata.