 Federal arrangements can also shelter territorially based groups with preferences that diverge from the majority population, such as ethnic or cultural minorities, so that they are not subject to majority decisions severely or systematically contrary to their preferences. Non-unitary arrangements may thus minimize coercion and be responsive to as many citizens as possible (Mill 1861 ch. 15, Elazar 1968; Lijphart 1999). Such considerations of economic efficiency and majority decisions may favor federal solutions, with “only indivisibilities, economies of scale, externalities, and strategic requirements … acceptable as efficiency arguments in favor of allocating powers to higher levels of government” (Padou-Schioppa 1995, 155).