ABSTRACT
The idea of migration as a system incorporating a network of origins and destinations that change through time was raised in the previous chapter. Originally conceptualized for the analysis of internal migration, the system was assumed to be bounded by the nation state. It is also possible to examine subsystems of movement within any single country, and particularly in a large country, linking some regions more intensively together than others. When we come to international movements ‘consideration of an all-encompassing global system would not be very enlightening’ and separating one system from another becomes an important issue (Zlotnik 1992: 19). While this point is generally well taken, no system that can be identified at the international level will be entirely closed and there will always be ‘spillage’ into other systems. There may be some benefit in considering the world as a whole, at least to see not only how and why the major systems have evolved but also how they themselves interact, no matter how tenuously. Nevertheless, identification of system boundaries becomes a major methodological issue. Zlotnik (1992) would delimit the system on the basis of the strength of the linkages as measured by the number of migrants from country A in country B. A threshold therefore needs to be established to separate ‘strong’ linkages, included within the system, from ‘weak’ linkages, excluded from the system.
