The economic theory of clubs can offer eminent contributions to an efficient shaping of processes of integration, especially at the level of the European Union. To determine a welfare maximum in a world full of clubs, the distinction between the within-club point of view and the total economy point of view plays a decisive role. The article tackles this conflict in already existing clubs realizing their optimal size in connection with the principleagent- problem between club members and club managers. Including the indivisibility problem of individuals and clubs in a more realistic perspective leads to a further problem typical for welfare maximization in a world full of full (i.e. optimally sized) clubs: the situation of those who will not be provided with the club goods. Three possible options taking care of those unprovisioned are distinguished, and it is analyzed how these options affect individual and social net benefit. It is shown that the efficiency of these options decisively depends on the within-club or total economy perspective implying specific principal-agent-problems. Some economic policy conclusions are drawn at the end applying the Frey/Eichenberger-Model of Functional Overlappung Competing Jurisdiction to the European Integration Process.
