This contribution concerns a study that aims to trace factors that determine the effectiveness of policy implementation. To this end, a case study was conducted in two municipalities. In both municipalities, a random sample was drawn of 100 activities in the cultural field carried out in the year 2021. Based on this, the effectiveness of the implementation of subsidy provision was examined for both municipalities. This effectiveness has been operationalised to the percentage of correct non‐applications, the percentage of rightly approved subsidy applications and the percentage of rightly rejected subsidy applications. A comparison between these municipalities, based on an analysis of the documents and 22 interviews, then provided an opportunity to explain differences in effectiveness. It turns out, that the control function provides the decisive explanation for the difference in effectiveness. This control function is not only about monitoring and controlling the implementation, but also about facilitating and optimising the process of providing subsidies. Although previous research highlights the importance of an adequate monitoring and control for implementation, the control function can be defined in a broader way. Besides overseeing proper implementation, the control function in this broader view also plays a facilitating role towards the implementers. This broader control function specifically has not often been the explicit object of implementation research. It should be noted, however, that this study is based on only two municipalities, which only examined the subsidisation of cultural activities. Therefore, no general conclusions can be drawn on this basis.