Getting the best results in controlled rounding with the least effort

Abstract

This paper describes computational experiments with an algorithm for control-rounding any series of linked tables such as typically occur in official statistics, for the purpose of confidentiality protection of the individual contributors to the tables. The resulting tables consist only of multiples of the specified rounding base, are additive, and have specified levels of confidentiality protection. Computational experiments are presented demonstrating the considerable power of the program for control-rounding very large tables or series of linked tables. Heuristic approaches to problematic cases are presented, as are procedures for specifying the input to the program. The statistical properties of the rounding perturbations are described, and a method of overcoming statistical bias in the rounding algorithm is demonstrated. © Springer-Verlag 2004.