The construction and use of sample design variables in EU-SILC. A user’s perspective

Currently, EU‐SILC is the single most important data source on income and living conditions in the European Union. It is widely used to inform policy makers and it constitutes a major resource for social research on the social situation in the European Union and its member states. As EU‐SILC consists of samples in every EU Member State, estimates based on EU‐SILC should be accompanied by proper standard errors and confidence intervals to indicate the precision of the estimates. In order to compute accurate standard errors, it is essential to take account of the sample design. In this report the quality of the variables which should enable the latter is discussed as well as the documentation of the sample design in every EU Member State. The report lists the most important problems and shortcomings of these variables and develops practical recommendations to improve their quality and usefulness. Furthermore, some suggestions are made for better documenting the sample design in the national quality reports. The main conclusions are: (1) especially in countries with complex sample designs the sample design variables do not always reflect the real sample design; (2) the sample design should be better documented in the national quality reports in order to facilitate the evaluation of the sample design variables. The main recommendations are: (1) the responsible persons at the national statistical offices should be informed on the use of the sample design variables; additionally they should receive more guidance in the construction of the sample design variables and the description of the sample design in the national quality reports; (2) a discussion should be organised about the organisation of sample designs in the future: in some countries they seem to be unnecessarily complex, lacking an adequate sampling frame and so prohibiting the correct computation of sampling variances; (3) a research‐based discussion should be organised about the possibilities to disclose all sample design variables in the UDB.