 Federal arrangements may not only protect existing clusters of individuals with shared values or preferences, but may also promote mobility and hence territorial clustering of individuals with similar preferences. Member unit autonomy to experiment may foster competition for individuals who are free to move where their preferences are best met. Such mobility towards member units with like-minded individuals may add to the benefits of local autonomy over the provision of public services—absent economies of scale and externalities (Tiebout 1956, Buchanan 2001)—though the result may be that those with costly needs and who are less mobile are left worse off.