Abstract
In recent decades, several important contributions have been made to further our understanding of whether and how ideas affect policies. More recently, research have turned towards the question of why certain ideas gain prominence in policymaking processes at the expense of others. However, in answering this question there seems to be a continuing blind spot in terms of fully understanding the role of knowledge production within state bureaucracies in determining which ideas are inscribed into policy and which are not. This article offers new insights to the ideational literature by showing how the use of institutionalised and systematic production of knowledge within state bureaucracies is pivotal for explaining the power of ideas. This is demonstrated through an in‐depth and illustrative case study of the policymaking process leading up to a major reform of Danish activation policies in 2014. In this case, an evaluation system institutionalised within the Ministry of Employment significantly shaped the types of knowledge utilised in the policymaking process and the final design of the policy reform. Consequently, the evaluation system instated a bulwark against ideational shifts in every phase of the policymaking process. Thus, ultimately steering the policymaking process in the direction of ideas grounded in a Work First approach rather than the Human Capital approach initially promoted by the Minister of Employment.