In general, pooling and delegating functions and policies to supranational institutions to take advantage of economies of scale and scope, while maintaining other prerogatives at the national (or sub-national) level, has brought substantial benefits to Europeans when appropriately implemented in areas with relatively low heterogeneity costs. Those benefits have been obtained while keeping ultimate sovereign control and the monopoly of the legitimate use of coercion at the national state level. A centralized European authority could provide a broader range of public goods with large economies of scale and scope, while using coercion to prevent free riding. But that would come with much higher heterogeneity costs. Europeans have probably been wise not to travel all the way to a sovereign federation so far, given their existing differences in preferences and cultures. If those preferences change, Europe may benefit from a reorganization in a federal direction, but of course that should be decided only through broad and democratically expressed consensus.