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  • Articles and reports: 12-001-X199400214420
    Description:

    The statistical literature contains many methods for disclosure limitation in microdata. However, their use by statistical agencies and understanding of their properties and effects has been limited. For purposes of furthering research and use of these methods, and facilitating their evaluation and quality assurance, it would be desirable to formulate them within a single framework. A framework called matrix masking - based on ordinary matrix arithmetic - is presented, and explicit matrix mask formulations are given for the principal microdata disclosure limitation methods in current use. This enables improved understanding and implementation of these methods by statistical agencies and other practitioners.

    Release date: 1994-12-15

  • Articles and reports: 12-001-X199400214426
    Description:

    In the MARS Project (Monitoring Agriculture with Remote Sensing) of the E.C. (European Community), area frames based on a square grid are used for area estimation through ground surveys and high resolution satellite images. These satellite images are useful, though expensive, for area estimation: their use for yield estimation is not yet operational. To fill this gap the sample elements (segments) of the area survey are used as well for sampling farms with a template of points overlaid on the segment. Most often we use a fixed number of points per segment. Farmers are asked to provide global data for the farm, and estimates are computed with a Horvitz-Thompson approach. Major problems include locating farmers and checking for misunderstanding of instructions. Good results are obtained for area and for production of the main crops. Area frames need to be complemented with list frames (multiple frames) to give reliable estimates for livestock.

    Release date: 1994-12-15

  • Articles and reports: 12-001-X199400114433
    Description:

    Imputation is a common technique employed by survey-taking organizations in order to address the problem of item nonresponse. While in most of the cases the resulting completed data sets provide good estimates of means and totals, the corresponding variances are often grossly underestimated. A number of methods to remedy this problem exists, but most of them depend on the sampling design and the imputation method. Recently, Rao (1992), and Rao and Shao (1992) have proposed a unified jackknife approach to variance estimation of imputed data sets. The present paper explores this technique empirically, using a real population of businesses, under a simple random sampling design and a uniform nonresponse mechanism. Extensions to stratified multistage sample designs are considered, and the performance of the proposed variance estimator under non-uniform response mechanisms is briefly investigated.

    Release date: 1994-06-15
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Articles and reports (3)

Articles and reports (3) ((3 results))

  • Articles and reports: 12-001-X199400214420
    Description:

    The statistical literature contains many methods for disclosure limitation in microdata. However, their use by statistical agencies and understanding of their properties and effects has been limited. For purposes of furthering research and use of these methods, and facilitating their evaluation and quality assurance, it would be desirable to formulate them within a single framework. A framework called matrix masking - based on ordinary matrix arithmetic - is presented, and explicit matrix mask formulations are given for the principal microdata disclosure limitation methods in current use. This enables improved understanding and implementation of these methods by statistical agencies and other practitioners.

    Release date: 1994-12-15

  • Articles and reports: 12-001-X199400214426
    Description:

    In the MARS Project (Monitoring Agriculture with Remote Sensing) of the E.C. (European Community), area frames based on a square grid are used for area estimation through ground surveys and high resolution satellite images. These satellite images are useful, though expensive, for area estimation: their use for yield estimation is not yet operational. To fill this gap the sample elements (segments) of the area survey are used as well for sampling farms with a template of points overlaid on the segment. Most often we use a fixed number of points per segment. Farmers are asked to provide global data for the farm, and estimates are computed with a Horvitz-Thompson approach. Major problems include locating farmers and checking for misunderstanding of instructions. Good results are obtained for area and for production of the main crops. Area frames need to be complemented with list frames (multiple frames) to give reliable estimates for livestock.

    Release date: 1994-12-15

  • Articles and reports: 12-001-X199400114433
    Description:

    Imputation is a common technique employed by survey-taking organizations in order to address the problem of item nonresponse. While in most of the cases the resulting completed data sets provide good estimates of means and totals, the corresponding variances are often grossly underestimated. A number of methods to remedy this problem exists, but most of them depend on the sampling design and the imputation method. Recently, Rao (1992), and Rao and Shao (1992) have proposed a unified jackknife approach to variance estimation of imputed data sets. The present paper explores this technique empirically, using a real population of businesses, under a simple random sampling design and a uniform nonresponse mechanism. Extensions to stratified multistage sample designs are considered, and the performance of the proposed variance estimator under non-uniform response mechanisms is briefly investigated.

    Release date: 1994-06-15
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