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In page Arthur MacMahon:

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Late in his career, MacMahon developed an interest in federalism, publishing three books on the subject. His first work on federalism was the collection Federalism, Mature and Emergent, which he edited. In his introduction to the book, MacMahon wrote about the process of European integration, and the gradual move towards a federalist Europe.[1] MacMahon also wrote two books on the subject of federalism himself: Delegation and Autonomy (1962) and Administering Federalism in a Democracy (1972).