This project intends to answer the question under what circumstances members of the European Commission, i.e. EU commissioners, act as committed Europeans vs. as agents of their respective member states. Recently, there have been some publications which have dealt with the behaviour of European Commissioners or of the Commission as a whole. But so far, there is no publication which developed quantitatively comparable measures of Commissioners’ individual behaviour to research it on the basis of theoretical argument. Since these three elements make up the specific aim of this project, this section shows in detail what the relevant literature so far has contributed to the academic discussion. It also shows the research gap, which the project aims at filling.