In all social sciences that participate in the interdisciplinary science of public administration and public policy, one can observe a revival of the institutional approach (Keman, 1997). Although these institutional approaches may differ in many respects, what they have in common is that they all characterize institutions as distinct systems of rules purporting to effectuate social practices in which those systems are realized. In some studies the social practices are set in the first place while the rules are considered to be of secondary importance. In other studies the analysis takes the reverse order of precedence. However, the dual nature of institutions is generally recognized. Using terms coined by the Austrian legal theorist Ota Weinberger, I call institutions qua distinct systems of rules ‘normative institutions’ and institutions qua social practices ‘real institutions’. (Weinberger, 1991: 20–21) Thus, a distinction can be drawn between the local authority ‘Amsterdam’ on the one hand and the local community ‘Amsterdam’ on the other. Likewise, a distinction can be drawn between the public limited company ‘Ajax’ on the one hand and the football club ‘Ajax’ on the other. Finally, a similar distinction can be drawn between, on the one hand, the outline of the European Union laid down in the EC Treaty, the Maastricht Treaty and the Treaty of Amsterdam and, on the other hand, the evolving, large-scale, real institution of that name.