The estimation of over- and underemployment in Germany is normally based on data of Mikrozensus (Ehing 2014: 4) or of the Socio-Economic Panel (SOEP). However, the results differ and may lead to different political conclusions. A recent publication of the Statistisches Bundesamt (Rengers 2015), which is based on the Mikrozensus 2014, points out that for 9.3 percent of the overall labour force actual work hours and preferred work hours differ. A majority of them would prefer to increase their actual work hours. Contrary to that, estimations based on SOEP 2012 (Holst/Wieber 2014) show that 71 percent of all employees face a mismatch between actual and preferred work hours with a majority preferring a reduction of their work hours.