ABSTRACT
The first substantive issue that should be clear from the discussions of migration and development in the five development tiers is that population movements are an integral part of the societies and economies of each one: the forms and type may differ, but people are highly mobile in each tier. The examination of the evolution of mobility should also have shown that the forms change over time and that it would be difficult to identify a time when migration was unimportant. Our era is certainly an age of migration, but it is not the age of migration. There have been many times in the past when migration has been just as significant. Although more people may be moving over longer distances today than ever before, this is due primarily to the fact that there are more people alive in the world today and that modern technological development in transport has facilitated the conquest of distance.
