Migration network theory addresses the cumulative causation of migration as a result of reduced social, economic, and emotional costs of migration pursuant to the formation of migration networks. Because it introduces a sociological dimension, network theory improves the mechanical and economistic “push and pull” conceptions that prevailed earlier, including world systems versions thereof. Nonetheless, existing treatments of migration networks overlook the role of those networks in expanding the immigrant economy at locations of destination. The migration network performs this role when it supports migrant entrepreneurship, a phenomenon of variable but often great importance. Existing literature also ignores cultural differences that affect the efficiency of migration networks in both relocating population and generating new firms. In the last decade, immigration research has refocused on the issue of migrant networks in both contemporary and historical migrations (Bozorgmehr, 1990; Fawcett, 1989; Boyd, 1989; Morawska, 1989: 260; Wilpert and Gitmez, 1987). A long-standing concern (Tilly, 1978; Choldin, 1973: Light, 1972), migrant networks became of renewed interest when researchers sought to connect macro and micro determinants of immigration. Micro determinants begin with solitary decision-makers who operate independent of group memberships (Lee, 1966; Lewis, 1982: ch. 8; Sell, 1983). Often placed in a world systems context, macro influences impact masses of people whose responses are not thought to depend upon migration chains (Burawoy, 1976; Portes and Walton, 1981; Clark, 1986: ch. 4; Sassen-Koob, 1989). Spanning continents and decades, social networks connect individuals and macroscopic push and pull influences. True, at any stage of a migration, some people arrange their relocation on their own and without any help from migration networks. These are unassisted migrants. However, more individuals migrate when once networks have formed (Portes and Boron, 1989: 607-608). These networks organize their departure, travel, and settlement abroad. For this reason, the network itself emerges as an actor in the migration process.
Although based on already familiar ideas, Massey’s formula of “cumulatively caused” migration drew together and focused current thinking about migration. According to Massey (et al., 1987; 1988, 1989), migrations forge networks which then feed the very migrations that produced them. Therefore, whatever macrosocietal political/economic conditions may initially have caused migration, the originating pushes and pulls, the expanding migratory process becomes “progressively independent” of the original causal conditions. In effect, migrations in process self-levitate above the conditions that caused them to begin, leading thereafter an independent existence. Network formation is the reason. Massey (1988: 396) defines migration networks as “sets of interpersonal ties that link migrants, former migrants, and non-migrants in origin and destination areas through the bonds of kinship, friendship, and shared community origin.”
Networks promote the independence of migratory flows for two reasons. First, once network connections reach some threshold level, they amount to a autonomous social structure that supports immigration. This support arises from the reduced social, economic, and emotional costs of immigration that networks permit. That is, network-supported migrants have important help in arranging transportation, finding housing and jobs in their place of destination, and in effecting a satisfactory personal and emotional adjustment to what is often a difficult situation of cultural marginality. These benefits make migration easier, thus encouraging people to migrate who would otherwise have stayed at home. Unless migrants are uprooted refugees who lack any choice about departure, only immigration affording them any hope of survival (Bozorgmehr and Sabagh, 1990; Pedraza-Bailey, 1985) potential migrants always have the option of staying home. Given that choice, the reduced cost of migration enhances the number who can and will choose to leave, thus increasing the volume of migration.
Second, Massey has made the same case for networks under the assumptions of a risk-diversification model.According to this model, families allocate member labor within the constraint of their own needs and aspirations in a cost-efficient and risk-minimizing way.Many Third World households are economically precarious. Such households face high-risks to their well-being if they select non-migration.Moreover, modernization and development create social and economic dislocations that intensify the unstable and unpredictable economic environment created by the usual risks of drought, crop failure and natural disasters, for rural as well as urban areas.In the absence of other ways to insure against such risks, diversification of family members’ location minimizes overall family income risk. (Massey, 1989: 14-15)
Migration is a risk-diversification strategy.International migration is especially effective because international borders create discontinuities that promote independence of earnings at home and abroad. Good times abroad can match bad ones at home, or vice-versa. Even in the absence of earning differentials (ASA, p.15), international migration offers an effective risk-diversification strategy, especially when migrant networks already exist. Migration networks reduce the economic risks of immigration, thus rendering the strategy more attractive from a risk-diversification perspective (Massey, 1989:5-16). Expanding networks “put a destination job within easy reach of most community members” (Commission, p.398) and make migration a virtually risk-less and cost-less alternative labor power investment in the household’s portfolio of labor assets (Massey, 1988).