Australia is the site of a quite remarkable social experiment. In just over four decades since the post-war immigration program began, the Australian population has more than doubled, from 7.5 million in 1947 to 16 million by the mid eighties. Without immigration, given the birth rates of the native bom, the Australian population would now be only about 11 million. This in itself is not remarkable. Mass migration has been one of the most important historical features of the era of global industrialisation, from the country to the city, the developing to the developed world, from points of crisis to points of quieter affluence. But, in a half century when global mobility has been greater than ever before, Australia’s immigration program has been greater than that of any first world country relative to the size of the existing population, bar the peculiar historical phenomenon of the establishment of the state of Israel in British Mandated Palestine.