There is barely a week passing by without international newspapers covering Beijing’s hazardous smog levels. It is very clear that Beijing’s ambient air quality is far away from being perfect，let alone healthy. What international news coverage often neglects，however，is the fact that also many European and American cities suffered from air pollution several decades ago. This research paper therefore aims at putting the experiences made by China (Beijing) into direct comparison with the ones made by Germany (the Ruhr Area)，who had to contend with similar problems in the past. Since it is often stressed that China’s environmental problems stem from weak policy implementations at the local level，this thesis tries to analyze the difficulties both research objects faced/are still facing，when it comes to environmental policy formulation and enforcement with the help of principal-agent theory. It is argued that in both countries/systems the principal-agent problem is prevailing in its very own way and slowing down effective air pollution control. Against the background of the possibilities and difficulties that both systems entail it will also be assessed，why Beijing in the future could be more efficient in controlling air pollution than the Ruhr Area had been. In consideration of the latest developments that are taking place since the change of leadership in 2013 with regard to air pollution prevention and control this topic gains even more importance.