An application of information theory to the problem of statistical disclosure

By using prior knowledge it may be possible to deduce pieces of individual information from a frequency distribution of a population. If the prior information is described by a stochastic model, an information-theoretic approach can be applied in order to judge the possibilities for disclosure. By specifying the stochastic model in various ways it is shown how the decrease in entropy caused by the publication of a frequency distribution can be determined and interpreted. The stochastic models are also used to derive formulae for disclosure risks and expected numbers of disclosures.