The interplay among intergovernmental and supranational actors is a defining feature of the institutional life of the European Union (EU). Too often, however, these actors are considered independent of each other, and their autonomy is assessed in a vacuum. This is problematic because if there is such a thing as “endogenous preferences” in the EU, it appears exactly through this interdependence of intergovernmental and supranational actors. None of the institutionalist approaches to the EU has come to grips with this fact yet. Based on some very simple game-theo- retic ideas, I offer in this article a rationale for “endogenous preferences” and discuss their impact on issues of delegations. Some cursory empirical evidence supports the claims that the preferences of supranational actors are related to those of the actors who select or appoint them. Similarly, the analyses presented here suggest that preferences over delegation to supranational actors are influenced by differences in policy views between principals and agents.