The “Kreditanstalt für Wiederaufbau” (KfW) has been establishing a firm panel on the basis of paper-and-pencil interviews which is representative of medium-sized and large companies since 2002. Companies of all sizes (except for large businesses), of all economic sectors and of all age-related cohorts are to be gathered. The purpose of this panel is the continuous coverage of the development of companies promoted by KfW in particular and, at large, of medium-sized companies. Furthermore, this panel should serve the evaluation and further development of measures which promote small and medium-sized companies. In order to fulfil these multiple ambitions, the medium-sized panel relies on a sample of promoted as well as non-promoted companies. In addition, in order to preserve the representativity of the promoted as well as of the non-promoted companies, the panel has to be adjusted periodically to the dynamics of the respective populations. The conception and preparation of the sample(s) was conducted by ZEW in 2002. The first two waves of the KfW medium-sized panel lean on these samples. For the next waves, an adaptation of the samples was undertaken. For this purpose, the dynamic of start-up by economic sector was taken into consideration, sample failures were adequately replaced and potential changes between non-promoted and promoted companies were also considered. In this context, ZEW undertook the conception and preparation of the sample, which had to be altered for the next round of the survey. KfW made available information about the cases which had yet been realized in the previous panel waves as well as information about new cases of promotion. For the sampling procedure, ZEW added this information from the “Mannheim Enterprise Panel” (MUP). For the following wave, a renewed adaptation of the samples is conducted on the basis of the previous survey waves. Prior to the sampling procedure, the basis of the drawing of the businesses promoted by KfW on the one and of the businesses which are not promoted by KfW on the other hand has to be edited. On the basis of the information from the promotional programs, KfW has an enormous number of companies’ addresses at its disposal. For a partial timeframe, data of the DtA, which in the meantime merged in the KfW, has also to be considered for the preparation. In the process, it might also happen that companies participate in the promotional programmes of the DtA as well as those of the KfW. In order to prevent that these “multiple” participants are repeatedly taken into the basic file for the sampling procedure, in a first step, “multiple” participants have to identified. In a second step, with a reconciliation of cases which were realized in the previous waves, the new KfW (former DtA cases included) and ZEW data, companies have to be identified which have not received promotion from KfW. The base data is composed of the data file brought together in the first step and a data file of the ZEW data. The procedure for the reconciliation is the one described above. As a result, a data file of potential sample companies which do not receive promotion by the KfW (DtA, respectively) and which have not yet been counted among the sample of the previous waves, emerges.