Zusammenfassung:
With the upswing of populist, right-wing and EU-sceptic parties and politicians in Europe and the success of Donald Trump in the US presidential elections in 2016 media and their role with respect to the perception and decisions of individuals in the political context are (once again) in the focus of interest. This contribution introduces a new measure of political media bias by analyzing articles and newscasts with respect to the tonality on political parties and politicians. On this basis we develop a Political Coverage Index (PCI) sorting the outlets in the political left to right spectrum. We apply the PCI to 35 opinion-leading media in Germany, analysing 10,105,165 news items on political parties and politicians from 1998 to 2012. With this tonality-based approach we are able to achieve a more direct and reliable measure of media bias. In addition, we apply the PCI to investigate whether the media fulfil their role as the fourth estate, i.e. provide another level of control for government, or whether there is evidence of government capture. First results show that at least in Germany this seems to be not the case.