International migration to the United States experienced a dramatice change over the last two decades. The 1965 Immigration and Nationality Act that abolished the national origins quota system established in 1924, gave rise to a more diversified pool of legal immigrants. Unlike past immigration coming from Europe, most immigrants now come from developing countries mainly from Asia and Latin America. For example, between 1971 and 1990, while legal immigration from Europe decreased five percent, immigration increased rapidly from Central America (248 percent), Mexico (159 percent) and Asia (72 percent) (INS, 1992). Due to the operation of social networks it is likely that undocumented migration followed a similiar pattern. In this context, some contend that the arrival of new immigrants is accelerating the conentration of poverty in certain regions in the United States.