It amounts to a truism to say that amongst the great problems left by the Second Great War very few called for national and international planning so urgently as the problem of human migrations. During and after the conflicts a mass displacement of population was brought to bear heavily on the demographic situation of Western Europe. On the other hand, in the turmoil of the aftermath some western countries came to lose, one by one, their African and Asiatic colonies, and were in consequence deprived of an outlet for their surplus population. The economic implications of the problem were...