Remote access can be a powerful tool for providing data access for external researchers. Since the microdata never leave the secure environment of the data-providing agency, alterations of the microdata can be kept to a minimum. Nevertheless, remote access is not free from risk. Many statistical analyses that do not seem to provide disclosive information at first sight can be used by sophisticated intruders to reveal sensitive information. For this reason the list of allowed queries is usually restricted in a remote setting. However, it is not always easy to identify problematic queries. We therefore strongly support the argument that has been made by other authors: that all queries should be monitored carefully and that any microlevel information should always be withheld. As an illustrative example, we use factor score analysis, for which the output of interest - the factor loading of the variables - seems to be unproblematic. However, as we show in the article, the individual factor scores that are usually returned as part of the output can be used to reveal sensitive information. Our empirical evaluations based on a German establishment survey emphasize that this risk is far from a purely theoretical problem.
Record linkage has become an important tool for increasing research opportunities in the social sciences. Surveys that perform record linkage to administrative records are often required to obtain informed consent from respondents prior to linkage. A major concern is that nonconsent could introduce biases in analyses based on the linked data. One straightforward strategy to overcome the missing data problem created by nonconsent is to match nonconsenters with statistically similar units in the target administrative database. To assess the effectiveness of statistical matching in this context, we use data from two German panel surveys that have been linked to an administrative database of the German Federal Employment Agency. We evaluate the statistical matching procedure under various artificial nonconsent scenarios and show that the method can be effective in reducing nonconsent biases in marginal distributions, but that biases in multivariate estimates can sometimes be worsened. We discuss the implications of these findings for survey practice and elaborate on some of the practical challenges of implementing the statistical matching procedure in the context of linkage nonconsent. The developed simulation design can act as a roadmap for other statistical agencies considering the proposed approach for their data.