“The partisan politics of institutional welfare state reform” was selected by two of JEPP’s editorial board members (Christoph Knill and Frank Schimmelfennig) as the best article published in a normal issue of JEPP in 2015. In their award statement, the jury praises the paper for making “a highly important contribution to the welfare state and party politics literature”. The paper makes a novel argument with the objective to demonstrate that the government partisan effect is significantly stronger on institutional welfare state reforms than on ordinary social policy reforms. To probe this claim, the authors employ an innovative dataset and a mixed-methods research design. The jury, furthermore, highlights the paper’s exceptional findings, which fit well with existing research but also contradict a number of major points made by the literature on welfare state reform, including the role of party ideology and class politics. JEPP congratulates the prize winners for their exceptional work!