Since 2001 the Statistical Offices in Germany offer access to micro level panel data that linked information from various waves of a survey over time. These panel data enormously extended the research potential of data from official statistics by allowing dynamic analyses and control for unobserved heterogeneity via panel econometric methods. A second generation of data sets which became available recently has an even higher research potential. These new data combine information for firms gathered in different surveys (or from external sources) that could not be analyzed jointly before. Merging firm level data from different surveys to construct data sets that cover information on a wider range of variables than the ones collected in any of these surveys, one at a time, is the basic idea of the project AFiD. AFiD is an acronym for the German Amtliche Firmendaten für Deutschland (official firm data for Germany). The papers in this issue present first results generated with this new type of firm level data and discussions.weiterlesen