ABSTRACT
Within all the development tiers discussed so far there has been considerable variation, although all have had a functional unity of a sort. It might be thought that this last development tier, the resource niche, is no more than a convenient catch-all in which to consider the remaining parts of the world. What could the highly urbanized desert kingdoms of the Middle East, the dispersed hunter-gatherers of the Amazonian rainforests and the populations of the islands of the Pacific or the Caribbean possibly have in common? There are obviously huge differences in terms of cultures and development within this tier, between the futuristic architecture of some of the Gulf states, the luxury tourist resorts of Polynesia and the sun-dried clay houses of the Sahel. It would indeed be possible to create a whole series of developmental regions within this tier, but several common threads do seem to run through the diversity. The first is vulnerability: a vulnerability in terms of environmental issues, in terms of size and in terms of a tenuous link with the other development tiers, and particularly the old and new cores. Although, as we shall see, the volume of migration may not always rival that in the other tiers, it is in this development tier that the relative impact of the movement is perhaps the greatest. The most vivid common thread is that this tier has been and will be, in the foreseeable future, little more than a resource niche for groups in the first three development tiers.
